165/2004. Report on the U.S. NLDN System-wide Upgrade. Exploring Long-range Lightning Detection over the Oceans

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1 165/2004 Report on the U.S. NLDN System-wide Upgrade Exploring Long-range Lightning Detection over the Oceans Vaisala Radiosonde RS92 on Trial in Italy Vaisala Upgrades Dubai International Airport

2 Contents President's Column 3 Vaisala Remote Sensing Report on the U.S. NLDN System-wide Upgrade 4 Exploring Long-range Lightning Detection over the Oceans 9 Vaisala takes part in the 84 th American Meteorological Society Annual Meeting in Seattle 11 Vaisala Soundings Vaisala Radiosonde RS92 on Trial in Italy 12 Vaisala HydroMet Chilean Navy Weather Service Invests in Vaisala Automatic Weather Stations 18 Over the past two years, Vaisala has invested in the most comprehensive upgrade of the North American Lightning Detection Network to date. The upgrade included the installation of the new Vaisala IMPACT ESP Lightning sensors throughout the continental United States. The upgrade will improve the performance of the sensors, minimize maintenance and downtime and build a stronger base for future improvements. In May 2004 Vaisala's new clean room was taken into operation and the production of sensors was re-started. A clean room is a nearly particle-free area where air quality, temperature and humidity are carefully regulated to ensure that sensitive equipment is free from contamination. The new facility is state-of-the-art and will allow Vaisala to continue to produce high quality sensors for our products. Update of the Vaisala Automatic Weather Stations MAWS101 Monitoring Transmission Lines 19 Hydrometeorological Real-time network in North-eastern Italy 20 Co-operating to Improve Water Quality Measurements in Finnish Waterways 22 The Vaisala Radiosonde RS92 family has been available on the market for over a year. In November 2003 and March 2004 testing was carried out in Italy to compare the PTU measurement performance of the Vaisala Radiosonde RS92 and the Vaisala RS90. Vaisala Road Weather Norwegian Roads Safer with Vaisala's Remote Measurement and Forecasting Technology 23 Vaisala Aviation Weather Vaisala updgrades Dubai International Airport 24 General Cover photo: Grand Canyon, Arizona USA Vaisala Invests 6.5 million Euros in New Clean Room 26 Secretary General of the World Meteorological Organization Visits Vaisala 28 In Vaisala 30 Vaisala in Brief We develop, manufacture and market products and services for environmental and industrial measurements. The purpose of these measurements is to provide a basis for a better quality of life, cost savings, environmental protection, improved safety and better performance. We focus on market segments where we can be the world leader, the preferred supplier. We put a high priority on customer satisfaction and product leadership. We secure our competitive advantage through economies of scale and scope. Editor-in-Chief: Angela Billings Publisher: Vaisala Oyj P.O. Box 26 FIN Helsinki FINLAND Phone (int.): Telefax: Internet: Design and Artwork: Edita Prima Printed in Finland by Edita Prima, Finland ISSN NORDIC ENVIRONMENTAL LABEL Printed matter 2 165/2004

3 President s Column Insource the core, outsource the context creasingly more expensive to maintain resources for that on the local level. The paradigm is changing and the key word today is service. I believe that our customers will increasingly need services as they begin to focus their resources on their core activities. At the same time they will increasingly want supporting services from a reliable partner. Our technical and application competencies give us a good position to take responsibility in system integration, maintenance, operations, financing, and to meet the ultimate needs of the customer: deliver high quality information and data. Vaisala has done similar things in our own industrial activity. We rely on competent service providers, who have devel- Insource the core, outsource the context is a business slogan, which is applied in many global companies. The key message is that in order to be competitive, resources should be focused on the core activities of the business, that is to say, to areas which generate a competitive edge. Non-core or context activities should be purchased from competent service providers. At times it is even better to take some of the core pieces from strategic partners, if you are unable to meet the volume required by that activity. I believe that this guidance applies equally well to the meteorological community. For most of our customers the ultimate need is weather observation data or further value added information, supporting operational decision making in a specific application. Activities such as integrating and installing a system, owning it, operating it and maintaining it, have all traditionally been mandatory in order to meet one's need for data or information. Those originally mandatory activities may have changed over time to become activities determined to be context. Technology development is also creating a push for change. Increasing automation makes equipment challenging to maintain and upgrade. During the equipment's lifespan upgrades can increase the value of data and information. Using the Internet enables new system architectures, where central processing can be done efficiently on a global level. More skills are needed to manage the recent developments in technology and it is inoped expertise by focusing their efforts on their core. A wide range of manufacturing activities belongs to this category. This transformation has helped us to develop our competitiveness and growth. I may have been a bit provocative above. But we have good experience already in many areas of shifting from being solely a provider of hardware to providing services and data. In the U.S we already provide lightning data to multiple applications. This will be an area to increase our offerings. Let's talk about it. Pekka Ketonen President and CEO 165/2004 3

4 Michael J. Grogan Product Manager, Network Data and Software Vaisala Tucson, USA Vaisala's U.S. National Lightning Detection Network Report on the U.S. NLDN System-wide Upgrade Two years ago, Vaisala began an ambitious project to re-build the National Lightning Detection Network (NLDN) by replacing more than 100 early generation sensors with new, more sensitive lightning sensors to improve network performance and expand applications. Initial third-party validation studies indicate that the network is operating better than ever with minimum 90 percent flash detection efficiency /2004

5 Over the past two years, Vaisala has invested in the most sweeping upgrade yet of the NLDN with the installation of new Vaisala IM- PACT ESP Lightning Sensors at sensing stations throughout the continental United States. These new sensors replaced more than 100 of the first generation IM- PACT Lightning Sensors and older LPATS III Lightning Sensors. The main goals of the upgrade were to: Improve network performance by using newer sensing technology Minimize maintenance and sensor downtime by replacing aging sensors and sensing station equipment Build a stronger base for future improvements, including cloud lightning detection opportunities Pre-Upgrade Operations In the early 1990s, the NLDN consisted of early generation magnetic direction finding sensors. The network detected 65 to 80 percent of cloud-to-ground lightning discharges with location accuracy ranging from 2 to 4 kilometers. The first major upgrade project to the NLDN began in 1994 and was completed in Vaisala then Global Atmospherics partnered with the Electric Power Research Institute to improve network performance to produce operational benefits targeted at the electric utility industry. Electric power utilities needed more detailed information and more accurate lightning locations to design more effective lightning protection to improve the reliability of transmission and distribution systems. The focus of the upgrade project was to: Report strokes as well as flashes Improve location accuracy Increase percentage of lightning discharges detected Report peak current estimates for cloud-to-ground lightning strokes The primary means to achieve these goals was to employ the latest lightning sensor technology; a combination of time-of-arrival and magnetic direction finding methods in a single sensor, the original IMPACT Lightning Sensor. At the completion of the project, the network consisted of 47 of the new combined technology sensors and 59 of the existing time-of-arrival sensors. In central processing, the location and stroke processing algorithms were also refined and Image shows 24 hours of lightning data from the U.S. National Lightning Detection Network U.S. National Lightning Detection Network Backgrounder Weather forecasters in both public and private sectors use real-time lightning maps and individual lightning stroke characteristics from the NLDN to closely monitor thunderstorm development, strength, and paths for more accurate severe weather forecasting and for issuing warnings. NLDN users include the National Weather Service, NASA, FAA, and other government agencies. Operations that are affected by lightning and thunderstorms electric power utilities, airports, telecommunications, explosives handling and others rely on NLDN lightning data to tell which facilities are at increased risk from thunderstorms. NLDN information is used for monitoring current conditions and for studying past events. Since 1989, the NLDN has reported more than 20 million cloud-toground lightning flashes that occur every year, creating a comprehensive archive of lightning data used for statistical and forensic analysis. NLDN data is available to subscribers through various lightning mapping software and Internet lightning tracking services. These application tools are specialized for real-time lightning tracking and warning or for analysis of past lightning activity. Real-time data is delivered by satellite broadcast or TCP/IP. Historic lightning data is delivered by CD or via traditional Internet protocols. 165/2004 5

6 NLDN Timeline : Three separate regional lightning networks develop and operate at various locations. These networks using early direction finding methods for lightning detection 1989: Regional networks share data to establish a national network, the NLDN. This cooperative project is funded by the Electric Power Research Institute (EPRI) and operated by the State University of New York (SUNY) at Albany. For the first time, real-time data is available to users across the country. This will allow the first time ever improved. The result of the project was a new flash detection efficiency of 80 to 90 percent and 500-meter median location accuracy. The results of the upgrade were verified by independent validation studies. Upgrade Calls for All New Sensors A combination of aging equipment and the desire to improve performance by using more advanced technology led to initial planning of the next systemwide upgrade. After more than a year of planning and development, work began in November 2001 to install new and more advanced Vaisala IMPACT ESP Lightning Sensors throughout the network. The new sensors would replace the old sensors 1991: Real-time and historic lightning data becomes commercially available. 1993: NLDN Network Control Center is moved to its current location in Tucson, Arizona. 1994: Comprehensive customer research leads to the development of new, more powerful lightning display and lightning analysis software. 1995: First major system-wide upgrade completed with project partner EPRI. This upgrade added new lightning sensors that combined magnetic direction finding and time-of-arrival detection methods in a single sensor, the original IMPACT Lightning Sensor. NLDN began reporting flashes and individual return strokes within a flash. Flash detection efficiency increased to 80-90% with median stroke location accuracy of 500 meters. Today s NLDN consist of 113 lightning sensor locations across the continental U.S : Commercial applications of historic lightning data proliferate in electric power, insurance, and other industries as a result of improved location accuracy and application-specific software developments. 1998: The Canadian Lightning Detection Network, owned by Environment Canada, is completed. Operations for the CLDN are combined with NLDN operations in Tucson. The lightning data from the NLDN and CLDN sensors close to 200 sensors are processed on a single processing platform. 2000: NLDN real-time and historic lightning data is available on the Internet in several application-specific formats. 2003: Second major system-wide upgrade completed with replacement of aging sensors and earlier sensing technology with new, more advanced, third generation Vaisala IMPACT ESP Lightning Sensors throughout the network. Preliminary evaluations indicate overall minimum 90% flash detection efficiency and 60-80% stroke detection efficiency. Distinguishing Flashes and Strokes NLDN lightning flash data provides time, location, polarity, first-stroke amplitude, and multiplicity of each cloud-toground lightning flash. However, research has shown that there can be up to 20 return strokes that make up a flash and these strokes often strike the earth in different locations up to several kilometers apart. NLDN stroke data provides time, location, polarity, and amplitude of these strokes, providing the very detailed data needed for in-depth lightning analysis and lightning incident investigations. Flash data is most often used for general trending of lightning events; stroke data is critical for understanding specific incidents. Key Performance Measurements Median stroke location accuracy: 50 percent probability error for locating a cloud-to-ground stroke Flash detection efficiency: Percentage of cloud-to-ground lightning flashes detected by the network Stroke detection efficiency: Percentage of all return strokes within a flash detected by the network 6 165/2004

7 and several new sensor locations and relocations were planned to optimize network geometry. The combined magnetic direction finding and time-of-arrival sensing technology employed by each new IMPACT ESP sensor raises the benchmark for NLDN performance. This more advanced combined technology replaces the now outdated, stand-alone time-of-arrival technique and also updates the original IMPACT sensors. The IMPACT ESP the third generation of the IMPACT sensor has improved sensitivity, shorter dead time (less than 1 millisecond), and more processing power than its predecessor. Like earlier versions of the IMPACT sensor, the new sensor employs both electric and magnetic field sensing to provide both arrival time and azimuth information for each detected lightning discharge. A network of these new sensors can detect survey-level amounts of cloud lightning, depending on sensor spacing. This cloud lightning capability offers an important step toward more timely and more accurate nowcasting and forecasting since cloud lightning is a typical precursor to cloud-to-ground lightning as well as an indicator of heavy precipitation, downbursts, and other weather hazards. Cloud lightning is a valuable weather element used by aviation professionals, meteorologists, and others to issue thunderstorm warnings faster and more accurately by identifying thunderstorms earlier and providing more detailed storm information. Cloud lightning detection capabilities using either the IM- PACT ESP sensors or its 2004 successor, the Vaisala Thunderstorm Total Lightning Sensor LS8000, is currently being evaluated. Preliminary Results Median stroke location accuracy of the NLDN is scientifically validated at 500 meters. The upgrade may have improved location accuracy in some regions, especially boundary areas, but location accuracy improvements are expected to be incremental and are currently undergoing re-validation. In 1998, flash detection efficiency was scientifically verified to range from 80 to 90 percent for those events with peak currents above five kiloamps, varying slightly by region. As of March 2004 the actual performance of the NLDN is still being confirmed by independent scientific evaluation, but preliminary evaluations and statistical models look promising. One evaluation project using digital video cameras with GPS time synchronization conducted by Kenneth E. Kehoe and University of Arizona professor E. Philip Krider around Tucson, Arizona at a boundary of the network during the summer of 2003 determined that average NLDN flash detection efficiency for 18 storms near Tucson was about 95 percent and stroke detection efficiency was about 78 percent. A paper on this study is scheduled for presentation at the 18th International Lightning Detection Conference in June Observations in these other areas are also being evaluated: Higher multiplicity Detection of smaller median peak current Lightning type classification for strokes below 10 to 20 kiloamp range Significant Increase in Stroke Detection The most promising preliminary result thus far is the increase in stroke detection efficiency from 40 to 50 percent in 1995 to 60 to 80 percent today an increase of 20 to 30 percent. Evaluations indicate the upgraded network detects more small subsequent strokes. This increase in stroke detection efficiency NLDN Mission: Quality and Value The NLDN s high standards of reliability, availability and performance are the result of well-planned redundancy and strict, documented quality control. NLDN operations are constantly scrutinized from data acquisition from the sensors to data delivery to customers. Here are a few highlights: Network Control Center for the NLDN and CLDN is manned 24 hours a day, 7 days a week, 365 days a year. System-wide Redundancy Two separate satellites and acquisition hubs acquire data from two evenly distributed sensor configurations. If one satellite, its hub, or its hub communication link fails, the sensor set reporting to the remaining satellite and hub provides sufficient coverage across the United States; Private carrier-grade communications system of direct links with back-up links in the event of a primary circuit failure; Two central processors operating independently with automatic fail-over for uninterrupted analyzes of incoming sensor data and lightning solution output; Back-up network control center is available at State University of New York at Albany. Quality Control NCC operators review regional network performance hourly using a graphical statistical analysis tool displayed by the central processor; Comprehensive statistical reports on regional network performance and on individual sensor performance are generated by the central processor and reviewed daily by staff scientists; Failure notification of any individual sensor occurs within one minute; On-call repair and maintenance staff are dispatched to sensor sites usually within 48 hours of sensor failure and regional technicians can provide even more rapid response when needed. Uptime and Availability % average uptime for data acquisition from sensors (2003) % average availability of data broadcast to users via satellite (2003) % average availability of Internet services (2003) Mission Critical Operations NCC is staffed 24 hours a day, 7 days a week, 365 days a year. Controlled access to NCC. Uninterrupted power supply with gas generator for sustainable power source to the NCC. Disaster recovery procedure in place. 165/2004 7

8 leads to the increase in flash detection efficiency. Validation Results Forthcoming Video evaluation is underway near Dallas, Texas, which is considered to be an interior network location. In addition, detection efficiency, location accuracy, and peak current calibration studies are being carried out by researchers at the University of Florida's International Center for Lightning Research and Testing in Camp Blanding. Finally, relative detection efficiency measurements will be produced so that NLDN users will be able to compare 2002 and later lightning information with previous years. Like validation studies after the upgrade, final evaluation results from the GPSsynched digital video evaluations and relative detection efficiency analysis of the upgrade will be made available to NLDN users as they become available. Key Applications for NLDN Lightning Data Weather forecasting: Help predict severe weather for public warning Electric power utilities: Pre-position field crews for approaching storm threats and to improve engineering and design with lightning analysis Air traffic management: Re-route aircraft around hazardous thunderstorms Airports: Suspend high-risk activities like fueling during lightning threats Insurance and arson: Investigate lightning as the cause of property damage or fire Power-sensitive operations: Prepare for storm-caused power outages by switching to back-up power early Hazardous materials handling: Warn personnel working near explosives and flammable materials to evacuate Forestry: Dispatch crews to suspected fire starts for more successful initial attack Golf and outdoor recreation: Warn players to seek safety from storms Aerospace: Monitor for safest weather conditions for shuttle and satellite launches Comparison: Before and After the NLDN Upgrade Basic Parameters Before After* Number of sensors Types of lightning sensors First generation IMPACT sensors Third generation Vaisala and older LPATS III sensors IMPACT ESP sensors Sensing technology Combined MDF/TOA sensors Combined MDF/TOA sensors and TOA only sensors Flash detection efficiency 80-90% 90% or better Stroke detection efficiency 40-50% 60-80% Stroke location accuracy 500-meter median error 500-meter median error Network uptime > 99.7% > 99.7% Minimum peak current detected (1st percentile) As low as 5-8 ka As low as 3-4 ka Multiplicity 1.9 to 2.4, varying by region Increased by 20-30% *Independent validation studies were still underway in March 2004 to verify these preliminary findings 8 165/2004

9 Nicholas W. S. Demetriades, Research Scientist Ronald L. Holle, Meteorologist/Consultant Vaisala Tucson, USA Exploring Long-Range Lightning Detection over the Oceans Vaisala's Research in transoceanic lightning tracking points to more accurate prediction models and improved aviation and maritime transportation safety. Vaisala and its research partners are studying cloud-to-ground lightning tracking techniques, effectiveness, and applications with experimental versions of Vaisala IMPACT ESP Lightning Sensors that use very low frequency (VLF) lightning detection technology. Long-range lightning data over ocean areas looks especially promising for more accurate numerical weather prediction models and storm forecasts for densely populated coastal areas. It also improves weather observations where undetected hazardous weather impacts aviation and shipping transportation routes and safety. Lightning Adds New Dimension Oceanic weather observations are collected primarily from these sources: Surface weather observation stations aboard ships and buoys Aircraft Geostationary and polarorbiting satellites Upper air soundings from islands The quality of these observation methods continues to be improved and refined, but the data quantity and type have not changed substantially. Using these data sources, numerical weather prediction forecasts of oceanic storm positions can still be off by hundreds of kilometers, resulting in adverse impacts to coastal communities. Preliminary long-range lightning observations and research models over the Pacific and Atlantic Oceans and Gulf of Mexico suggest that lightning mapping may be able to improve oceanic storm location accuracy and therefore significantly reduce forecast errors. Transportation Routes and Safety Ships and aircraft face severe weather hazards that threaten human safety and can result in damage or loss of goods being transported. By knowing where and when convective weather is active, dispatchers and air traffic management can modify routes to avoid thunderstorm hazards. As it does over land masses, lightning enables faster and more accurate identification of convective weather. Since 165/2004 9

10 Kathryn Schlichting Marketing Manager Vaisala Sunnyvale, USA radar is not available over the oceans, lightning data is even more important for accurate identification of formation and dissipation of convective cells. Satellite imagery is available over the oceans, but does not provide the level of detail and timeliness that lightning data can provide. Satellite imagery is often of limited use for identifying convective activity when obscured by higher clouds. Pacific Ocean Research For lightning activity mapping over the north and central Pacific Ocean areas, experimental longrange VLF lightning sensors modified versions of Vaisala IM- PACT ESP Lightning Sensors were installed on the islands of Kaui and Kona, Hawaii and Dutch Harbor, Alaska. Data from these lightning sensors is supplemented with data from Pacific Coast-area sensors from Vaisala s U.S. National Lightning Detection Network and Environment Canada s Canadian Lightning Detection Network. Figure 1 shows five consecutive days of lightning activity over the North Pacific Ocean. Figure 2 illustrates how adding lightning to satellite imagery provides valuable detail about the convective areas of a cold front. Important Benefits Anticipated Research and development will continue in long-range cloudto-ground lightning detection and applications. Early obser- Vaisala is privileged to collaborate on long-range lightning applications with research teams from these distinguished organizations: Aviation Weather Center of the National Weather Service University of Hawaii School of Ocean & Earth Science & Technology and associated collaborators NASA s Marshall Space Flight Center National Weather Service Forecast Offices in Seattle, Jacksonville, and Upton University of Washington, Department of Atmospheric Sciences State University of New York at Stony Brook Department of Atmospheric Sciences Environment Canada Figure 1. More than 10,000 cloud-to-ground lightning strokes were detected over the North Pacific Ocean over a 120-hour period starting 00h00 UTC on 10 February and ending at 24h00 UTC on 14 February PHOTOCOURTESY OF NOAA/NWS. vations point to very exciting advances that extend the reach of lightning observations to areas where better identification of developing weather patterns and hazardous convective weather are needed to improve weather forecasts. Figure 2. Satellite imagery and long-range cloud-to-ground lightning detected between 1421 and 1721 UTC 18 December 2002 over the North Pacific. Flashes indicate convection along a cold front, in the cold pool behind the front, and ahead of the frontal system. The presence of lightning indicates convection in only a portion of the locations with high clouds shown by infrared satellite imagery. New Vaisala products introduced at AMS The AMS meeting is the host to the largest exhibit program anywhere in the atmospheric, oceanic and related sciences. It provides the best showcase for introducting new and innovative equipment in these industries. Vaisala had a number of products which launched at the AMS meeting including: Vaisala Thunderstorm Information System, the integrated technology lightning sytem Vaisala Ceilometer CL31 Vaisala CARBOCAP Carbon Dioxide Probe GMP343 Vaisala TacMet Tactical Meteorological Observing System MAWS201MP, the pole mounted sytem Vaisala Software Defined Receiver/Processor, SPS311, for use in the Vaisala DigiCORA New Vaisala DigiCORA Tethersonde features including balloon improvements for increased flight stability, and safety, as well as many software improvements and upgrades. Other Vaisala products of keen interest to visitors to the booth were the Vaisala Radiosonde RS92, Vaisala Incident Weather Observing Station IWOS, Vaisala Wind Profilers and Vaisala Ultrasonic Wind Sensor. Our booth was active with many AMS attendees stopping by to see our product offerings and talking with Vaisala personnel. First ever Vaisala workshop Vaisala held its first workshop at AMS and featured product presentations by the Soundings, Wind Profiler, and Thunderstorm groups. The four-hour workshop was a venue where Vaisala's new products and upgrades could be discussed in detail with a group of interested customers. Ken Goss, Director of Sales and Marketing for North America was extremely /2004

11 Vaisala takes part in the 84 th American Meteorological Society Annual Meeting in Seattle The 84 th American Meteorological Society (AMS) Annual Meeting was held January in Seattle, Washington. Vaisala was an active participant on many fronts including the exhibition, presentation of papers, the general public WeatherFest forum, hosting a workshop, and meeting with customers in all areas of our meteorological business soundings, aviation weather, wind profilers, hydrometeorology, thunderstorm detection and data systems, optical sensors and instrumentation. The AMS meeting was a resounding success. to the general public called WeatherFest. This interactive half-day science and weather fair is designed to promote the field of meteorology to students, elementary and secondary school teachers, media, and weather hobbyists of all ages. Educational materials were provided on the Vaisala U.S. National Lightning Detection Network and lightning safety at the Weather- Fest fair. George Frederick, Del Hildebrand and Geoff Bing in the Vaisala Remote Sensing section of the Vaisala Booth. pleased with the participation and outcome of the event. Vaisala s first AMS workshop was a resounding success for customers from a number of application areas. In a fast paced series of presentations, Vaisala brought them up to speed on our latest product offerings, noted Ken. The event was very well received with many important customers in attendence participating in productive group discussions. Vaisala presents six technical papers Research and Development (R & D) is an area in which Vaisala is constantly investing. We presented selected topics at AMS as our way of offering the newest in technological advances to the meteorological field. Six papers were presented by Vaisala R & D personnel from our Optical, Thunderstorm, Wind Profiler, and Soundings groups. These papers were published by AMS and distributed to everyone attending the conference sessions. Involving the general public This year Vaisala participated in the pre-conference event open Seattle offered good surroundings for AMS 2004 Overall, the AMS Annual Meeting attracted more then 3,400 attendees to 21 conferences and symposia as well as various workshops and courses. The WeatherFest, an educational event open to the public and the media, attracted over 1,000 people. Everyone enjoyed the venue with downtown Seattle offering its gourmet coffee, fresh salmon and seafood, lively Pike Place Market, and plenty of rain. The 2005 AMS Annual Meeting to be held 9-13 January in San Diego, California will have the conference theme, Building the Earth Information System. It will provide another opportunity for Vaisala to showcase its leadership in weather observation systems and instrumentation. 165/

12 Maria Rita Leccese Managing Director Eurelettronica Icas Srl Rome, Italy Vaisala Radiosonde RS92: On Trial in Italy /2004

13 The Vaisala Radiosonde RS92 family has been available for over a year along with the supporting Vaisala DigiCORA Sounding System and sounding software. Worldwide, a number of RS92 operational trials have been concluded successfully. A greater number are either underway or scheduled to begin soon. This article focuses on the RS92 trial that was conducted in Italy by Vaisala in collaboration with the Italian Air Force and Reparto Sperimentazioni di Meteorologia Aeronautica (ReSMA), the Center for Air Force Meteorological Research. The Italian Air Force trial was conducted in two test phases. The first phase took place in mid-november 2003, the second in early March The Italian Air Force trial compared the measurement performance of the alldigital RS92-SGP to that of the RS90-AG, complete with their respective ground equipment and sounding software. Every dimension of radiosonde performance was analyzed. Special attention was paid to ensuring the continuity of aerological data when making the operational transition from the RS90 to the RS92. The first Vaisala Radiosonde RS92-SGP/RS90-AG test rig is launched at Vigna di Valle, witnessed by General Roberto Sorani, chief of the UGM. Italian Air Force Meteorological Service: some background The Italian Air Force has run a Meteorological Service since This service assumed a central role of national importance in 1950, when Italy joined the WMO. Over the years, the Italian Air Force Meteorological Service has built an extensive observation network which covers the national territory. Nowadays the Italian Air Force Meteorological Service acts as the national weather service, responsible for general weather forecasting, issuing weather bulletins and alerts for public safety. The Italian Air Force Meteorological Service runs 6 synoptic sounding stations located in Milano Linate, Udine Campoformido, Pratica di Mare, Cagliare Elmas, Brindisi and Trapani Birgi. The Italian Air Force Meteorological Service also carries out climatological and environmental analyzes in growing cooperation with the Regional Meteorological Services, which were formed to support local socio-economic activities by providing high-resolution, localized meteorological products. The Italian Air Force Meteorological Service is managed by Ufficio Generale per la Meteorologia (UGM), formed within the Comando Squadra Aerea with its headquarters in Rome. Reparto Sperimentazioni di Meteorologia Aeronautica (ReSMA) The Reparto Sperimentazioni di Meteorologia Aeronautica (ReS- MA) is the Center for Air Force Meteorological Research. Its responsibilities include overseeing the quality of meteorological observations, certifying the compliance of weather instruments to international standards and conducting special weather observation campaigns. Role of the Italian Space Agency in the trial Vaisala has developed a close relationship with the Italian meteorological research community over the years, in particular with the Agenzia Spaziale Italiana (ASI ), the Italian Space Agency. ASI s base in Trapani Milo has been a very active contributor to many European atmospher- 165/

14 The Reparto Sperimentazioni di Meteorologia Aeronautica (ReSMA) research station in Vigna di Valle. ic research programs thanks to its ideal location, modern instrumentation and highly trained staff. For these and other reasons, Vaisala came up with the idea of using the Trapani Milo base for initial operational testing of the RS92 in Italy. Vaisala approached ASI with the idea, the ASI kindly agreed, and RS92 operational tests were carried out in June 2002 and late September The encouraging results of the Trapani Milo test were the background to the Italian Air Force operational trial, which included tests at ReSMA s Vigna di Valle sounding station from 7-20 November 2003 and at the Trapani Birgi sounding station from 8-10 March Goals of the Italian Air Force trial The primary goal of the Italian Air Force trial was to compare the pressure, temperature and humidity (PTU) measurement performance of the Vaisala Radiosonde RS92-SGP to that of the RS90-AG currently used at Air Force sounding stations, as well as to assess the improved windfinding performance brought by Vaisala s new codecorrelating GPS technology. The secondary goal was to evaluate the benefits of upgrading to the Vaisala DigiCORA Sounding System MW21 from the Vaisala MARWIN Sounding System MW12 and Vaisala DigiCORA Sounding System MW11/15 systems currently in use. The Air Force testers directly compared the general usability of the MW21 and MW12 systems in light of their respective ground check procedures, reading of calibration coefficients and adjustment of transmitter frequencies. Phase 1, Vigna di Valle test Phase 1 of the Italian Air Force trial comprised 15 soundings made at the Vigna di Valle research station. Ten of the soundings were twin soundings of the RS92-SGP/RS90-AG; five were solo soundings. The majority of the twin and solo soundings were made at the standard synoptic times of 6:00, 12:00 and 18:00. The Vigna di Valle weather station often experiences radar interference from a nearby radar installation, which was an illuminating factor in the testing. Phase 2, Trapani Birgi test Phase 2 of the Italian Air Force trial comprised 7 soundings made at the Trapani Birgi sounding station, at the standard synoptic times of 12:00, 18:00 and 24:00 and hours in-between. Like Vigna di Valle, the Trapani Birgi sounding station often experiences radar interference from a nearby radar installation. Radiosonde set-up at Vigna di Valle Ten twin soundings of the Vaisala Radiosonde RS92-SGP/RS90-AG were made at Vigna di Valle. At launch, the radiosondes were suspended about 1 meter below the test rig. After launch and unwinding, the radiosondes reached a suspension point approximately 60 meters below the sounding balloon. The same was true for the 5 solo soundings that were made: four RS92-SGP soundings and one RS90-AG sounding. Radiosonde set-up at Trapani Birgi Seven soundings were made at Trapani Birgi. The radiosonde set-up was slightly different than the one used at Vigna di Valle. Trapani Birgi is a synoptic sounding station and the soundings were done so as not to disturb normal operation. The RS92-SGP and RS90-AG were not placed on a rig but launched separately and simultaneously. Ground equipment set-up Two sounding systems were used to collect data from the two radiosondes. ReSMA s existing Vaisala MARWIN Sounding System MW12 system was used to receive data from the RS90- AG. A newly installed Vaisala DigiCORA Sounding System MW21 was used to receive data from the RS92-SGP. At Trapani Birgi the existing Vaisala DigiCORA Sounding System MW15 system was used to receive data from the RS90- AG. A Vaisala DigiCORA Sounding System MW21 was used to receive data from the RS92-SGP. Both sounding systems were operated independently, in normal mode. The RS90- AG ground check was carried out as normal with the GC24 ground check set. The RS92-SGP ground check was carried out as normal with the Vaisala Ground Check Set GC /2004

15 Italian Air Force testers with a Vaisala Radiosonde RS92- SGP/RS90-AG test rig ready for launch. Figure 1. Vaisala Radiosonde RS80-15GE/RS92-SGP twin sounding: RS80-15GE humidity measurement in red, RS92-SGP humidity measurement in blue Data collection and processing RS90-AG data was collected from the Vaisala MARWIN Sounding System with a separate PC, loaded with Vaisala Metgraph software. The edited (EDT) data generated by the Vaisala DigiCORA Sounding System MW21 system was extracted from the MW21 s sounding database after every sounding a useful ability made possible by the new system architecture. The EDT data, generated every two seconds, was analyzed using the new RSK32 software developed by Mr. Sergei Kurnosenko. Vaisala Radiosonde RS92 vs. RS90 PTU performance PTU data availability The raw PTU data received by the MW21 and MW12 sounding systems was used to calculate the average availability of PTU data for the RS92-SGP and RS90-AG, as shown below: P T U RS92-SG 98.6% 97.5% 99.3% RS90-AG 86.7% 92.0% 92.6% Relative humidity The RS92 and RS90 measure relative humidity with similar performance the same humidity sensor is used for both radiosondes. This humidity sensor is made of an H-type polymer, which is a significant technological advance over the A-type polymer used in the manufacture of humidity sensors for RS80 radiosondes. Moreover, the RS90 and RS92 are equipped with two H- type humidity sensors and a technique which alternately heats them. When one H-type humidity sensor is measuring, its twin is off-line and heated to prevent icing in preparation for coming online. When the RS92 ascends through clouds at low altitudes, therefore, its humidity measurements are unaffected by icing. Furthermore, when the RS92 emerges from low-lying cloud, its humidity measurements are largely unaffected by the transition from the cloud s high-humidity conditions to normal atmospheric conditions. Spotlight: Vaisala Radiosonde RS92-SGP vs. RS80-15GE humidity measurement O ne RS92-SGP/RS80-15GE twin sounding was made to compare the humidity measurement performance of these two radiosondes (see Figure 1 above). A single sounding is not statistically significant. That said, the result reinforced the experience of recent WMO intercomparisons, which have shown that the RS92 s humidity sensor has a faster response time than the RS80 s humidity sensor and has a better temperature dependence correction, especially at cold temperatures (below -40 C). This is clearly seen in the 8 14 km altitude range of Figure 1. At an altitude of approximately 11 km, the RS92-SGP/RS80-15GE rig entered a cloud and the humidity measurements of the two radiosondes suddenly diverge widely. Vaisala Radiosonde RS92-SGP vs. RS90-AG humidity measurement The eight RS92-SGP/RS90-AG twin soundings carried out at Vigna di Valle were used to generate statistics on the direct differences in humidity measurement between the two radiosondes. As seen in Figure 2, the average direct difference was less than 3%. A factor which contributed significantly to the difference was the improved ground check procedure for the RS92. This procedure takes advantage of the new reconditioning functionality in the Vaisala Ground Check Set GC25. The reconditioning of the RS92 s twin humidity sensors eliminates any chemical contamination that may have occurred during storage to throw off humidity measurement during sounding. As seen in Figure 2, the RS92-SGP was used as the reference and measured higher humidity values than the RS90-AG at low altitudes (0-8 km) thanks to its reconditioned humidity sensors. The difference at higher altitudes is due to the slightly improved temperature dependence correction used for the RS92- SGP. In general, Figure 2 shows good correlation in humidity measurement between the RS92- SGP and RS90-AG, but a slight edge in performance must be given to the RS92-SGP. 165/

16 were compared to an external reference. The correction values were fed into the MW21 sounding system. Also following normal procedure, the RS90-AG was not pressure-corrected. Figure 3 shows the result: very minor differences between the pressure measurements of the two radiosondes at very low altitudes, and increasingly good correlation as higher altitudes are reached. Figure 2. 1 Average direct differences in humidity measurement, Vaisala Radiosonde RS90-AG vs RS92-SGP. The bold blue line in the middle shows the humidity values measured by the RS92-SGP used as the reference. The RS90-AG is the bold red line. Figure 3. 2 Average direct differences in pressure measurement, Vaisala Radiosonde RS90-AG vs RS92-SGP. The bold blue line in the middle shows the pressure values measured by the RS92-SGP, used as the reference. The RS90-AG is the bold red line. Vaisala Radiosonde RS92-SGP vs. RS90-AG pressure measurement The eight RS92-SGP/RS90-AG twin soundings of the Vigna di Valle test were used to compare the direct differences in pressure measurement between the two radiosondes. The RS92-SGP was pressure-corrected following normal procedure: the RS92- SGP s pressure measurements Vaisala Radiosonde RS92-SGP vs. RS90-AG temperature measurement The eight RS92-SGP/RS90-AG twin soundings of the Vigna di Valle test were used to compare the direct differences in temperature measurement between the two radiosondes. An improved temperature dependency correction has been developed for the RS92 temperature sensor. The results of this improvement are seen in Figure 4. Vaisala Radiosonde RS92-SGP vs. RS90-AG wind data availability The RS92-SGP s code correlating GPS (ccgps) technology enables highly accurate calculations of wind speed and direction and provides continuous wind data availability. The new ccgps technology also features a high signal-to-noise ratio and immunity to non-gps signals. Average wind data availability for the RS92-SGP as received by the MW21 sounding system was found to be 94.4% at Vigna di Valle and 95.5% at Trapani Birgi, based on calculations made with the raw GPS information received by the ground equipment. Average wind data availability for the RS90-AG as received by the MW12 sounding system was found to be 23.3%. Given that both test sites regularly experience strong external interference on the GPS band, the wind data availability figures for the RS92-SGP were considered to be very good. As the wind data availability figure of 23.3% shows, the RS90-AG is far more sensitive to radar interference than the RS92-SGP /2004

17 Figure 4. 3 Average direct differences in temperature measurement, RS90-AG vs RS92-SGP. The bold blue line on the right shows the temperature values measured by the RS92-SGP, used as the reference. The RS90-AG is the bold red line. Handling the Vaisala Radiosonde RS92-SGP and RS90-AG on the ground The Air Force testers compared the general usability of the Vaisala MARWIN Sounding System MW12/DigiCORA MW15 and Vaisala DigiCORA Sounding System MW21 in light of the respective ground check procedures, the reading of calibration coefficients and the adjustment of transmitter frequencies. The Air Force testers discovered that the GC25 simplifies the ground check procedure it reads calibration coefficients automatically, for example. They also found that the RS92-SGP is easier to handle than the RS90- AG. It is easier to take out of its package and assemble, easier to ground-check, and easier to launch thanks to its small size and simple, single-phase unwinder. The Air Force testers also noted the GC25 s humidity sensor reconditioning functionality and the benefit it provides: it improves the accuracy of humidity measurement by removing substances which may have contaminated the humidity sensors during storage or shipping. The Air Force testers also noted how easy it was to adjust the RS92-SGP s transmitter frequency with the GC25. As a general conclusion, they found the GC25 to be an improvement over older Vaisala ground check sets such as the GC24. Conclusions Like every national meteorological service, the Italian Air Force Meteorological Service takes great care to ensure the continuity of aerological data when adopting a new radiosonde for its upper-air program. Since the RS92 and RS90 radiosondes share the same PTU sensors, the Air Force testers did not expect to see significant differences in PTU measurement performance between the two radiosondes. This was not taken for granted, however, since the two radiosondes are different in size, weight and construction. The Italian Air Force trial was set up carefully to ensure that any differences in performance were indeed identified and analyzed. The similarities and differences that were found in the trial can be summed up in the following general conclusions: The differences that were seen in temperature measurement were attributable to the slightly different temperature dependency corrections used for the RS92-SGP and RS90-AG. The RS92 s temperature dependency correction is an improvement over the one used for the RS90. The differences that were seen in humidity measurement were attributable to the RS92 humidity sensor reconditioning and the RS92 s improved temperature dependency correction. Done as part of the ground check, the reconditioning solves the so-called "dry bias" problem of humidity measurement. The differences that were seen in pressure measurement were attributable to the fact that a ground reference pressure correction was applied to the MW21 used with the RS92-SGP, but not to the MW12 used with the RS90-AG. The differences that were seen in wind data availability were attributable to the fact that codeless GPS technology is used with the RS90-AG and correlating GPS technology is used with the RS92-SGP. The presence of external interference in the GPS band made the differences very substantial. Wind data availability with the RS92-SGP is significantly higher than with the RS90-AG. The RS92-SGP s alldigital data transmission was also a contributing factor. At the conclusion of the Italian Air Force trial, the Air Force testers welcomed the performance of the Vaisala Radiosonde RS92 for operational use in their upper-air program. Vaisala appreciates the spirit of cooperation that characterized the Italian Air Force trial. We send a special thank-you to Col. Giovanni Casu (Chief of ReSMA) and his personnel; Cap. Orazio Di Casola, M.llo Luigi Peloso and their personnel in Trapani; M.llo Claudio Esposito and Stefano Rocchetti from the 8 RTO maintenance group of Pratica di Mare. Footnotes 1 This Figure is based on the twin soundings made at Vigna di Valle. Each sounding generated approximately 3,000 rows of data. The differences seen in this Figure are 100% direct differences. 2 This Figure is based on the twin soundings made at Vigna di Valle. Each sounding generated approximately 3,000 rows of data. The differences seen in this Figure are 100% direct differences. 3 This Figure is based on the twin soundings made at Vigna di Valle. Each sounding generated approximately 3,000 rows of data. The differences seen in this Figure are 100% direct differences. 165/

18 Angela Billings Vaisala Helsinki, Finland Chilean Navy Weather Service Invests in Vaisala Automatic Weather Stations The Chilean Navy Weather Service has undertaken a 10-year METEO project to improve the reliability and accuracy of coastal weather information and has selected Vaisala Automatic Weather Station MAWS301 to meet their goals. The objective of the project is to improve the safety at sea by spreading more current information to ships along the Chilean coast. Over the course of 2003 the Chilean Navy Weather Service (CN- WS) decided to launch a 10-year project called METEO. An integral part of this project is the installation of Vaisala Automatic Weather Station MAWS301 in 20 existing Coastal Synoptic Stations as well as 20 new observation stations to be set-up along the coast. The MAWS301 station is equipped with sensors to measure wind velocity and direction (WAS425S), air pressure (PMT16A), and temperature, relative humidity, and precipitation (QMR102). The investment in the top of the line MAWS301 will help improve the reliability and accuracy of the data being collected from the various weather stations along the Chilean coastline. Making measurements in remote and difficult to access areas easy The Vaisala Automatic Weather Station MAWS301 is a new generation automatic weather station especially designed for applications where no commerical power or communication networks are present or are too expensive to be installed. The MAWS301 is a very flexible system which can be used for both hydrological and meteorological applications. Based on the latest technology both in measurements and communication, the MAWS301 can be interfaced with a multitude of telecommunication equipment such as standard PTSN and GSM modems, radio modem and satellite transmitters. The MAWS301 can even be connected directly to a LAN network via TCP/IP using standard COM Server devices. The Vaisala MAWS301 has been designed for applications where only a few sensors are required. The system can however, easily be upgraded, even in the field, to include a larger set of sensors, including smart sensors such as a ceilometer, visibility and present weather sensors and water quality probes. All of these functionalities made the MAWS301 particularly well suited for the Chilean coastal conditions as many of the existing and planned coastal synoptic stations are located in remote and difficult to access areas. Personnel and equipment has to be transported to the stations across fjords, channels, valleys and forests by use of helicopters, navy vessels or small boats. Accurate and reliable data improves the safety at sea Safety at sea requires accurate, real-time information. The CN- WS is responsible for monitoring weather conditions in the coastal areas of Chile, and for issuing bulletins and warnings about adverse conditions. Lighthouse personnel compile a Maritime Weather Forecast Analysis, which is broadcast through the Coastal Radio Network. The data collected by the new MAWS301 system, combined with existing, conventional equipment will greatly improve the accuracy of these reports, and the safety of vessels operating in Chilean waters. Vaisala: a complete service provider Vaisala, through its local representative in Chile, Metcom Limitada is providing the CNWS with technical support, assistance with installation and operation of the MAWS301, as well as operational training to the CNWS personnel. This arrangement of providing support services locally has lead to the successful first phase of this 10-year project /2004

19 Ritva Siikamäki, MA Helsinki, Finland The tests were conducted at a 500kV transmission line called President Dutra - Terezina II, in Maranhão State in Brazil. Mr. Sebastião José Gusmão Cavalcanti, the former CHESF transmission line designer, who acted as a consultant on the project, specified and installed a pair of Vaisala Automatic Weather Station MAWS101 on top of several towers on the site. He comments that this was the most trustworthy and efficient weather station he has ever worked with, after twenty years of experience with close to a dozen different types of instruments for this use. Although not using all the capabilities the system offers, the versatility of data acquisition modes on this instrument allowed him calculations, that were both precise and adequate for many purposes such as wind gusts or aeolic effects on towers, cables, insulation distances, pollution spreading, etc. The main objective was to assess the suitability and performance of the MAWS101 for monitoring overhead power transmission lines which are subject to all types of weather, including high winds. The wind information provided by the MAWS101 was used to monitor the performance of vibration dumpers. The MAWS101 is also being used to increase knowledge on the swinging and clashing risks of cables in huge bundles without spacers. Brazil has pioneered the so-called Expanded Bundle FEX, cables which are 1.4 meters apart, developed for high transmission lines. This new technology allows for the Vaisala Automatic Weather Stations MAWS101 Monitoring Transmission Lines In Brazil, Companhia Elétrica do Vale do São Francisco (CHESF), which provides electricity to eight North-Eastern States, has introduced the use of Vaisala Automatic Weather Stations MAWS101 atop overhead transmission line towers. The anemographs based on the data from the MAWS101 have been produced for more than one year and have proven useful in this application. adjustment of electrical parameters to increase power transmission by 25% without any additional costs. Further intended purposes of wind anemographs on transmission lines are to monitor the thermal dissipation conductors for Ampacity studies, i.e. to follow up the capacity of power transport of the line upgradings. Moreover, the data on wind gusts is used for monitoring the mechanical loadings of the structures. Vaisala wind sensors on a transmission line of Companhia Hidro Elétrica do São Francisco. Some of the test findings were presented in October 2003 at the national seminar on production and transmission of electricity (SNPTEE) sponsored by CIGRÉ in Uberlândia, Brazil. The paper (ref. IT-GLT- 024) presented examples of monitoring performed in the pioneer expanded bundle 230kV and 500kV transmission lines. Its main conclusion is to recommend the creation of a working group in CIGRÉ CE22 for the systematization of mechanical data acquisition and apply the procedures in the different types of transmission lines, environments and hardware in which risk expectations may suggest the need for historical observation. The Technical Report also outlines the updating of monitoring technology and instruments for predictive maintenance of both conventional and new expanded bundle transmission lines. The processor unit of the Vaisala Automatic Weather Station MAWS101 on a power pylon. 165/

20 Maria Rita Leccese Managing Director Eurelettronica Icas Srl Rome, Italy Vaisala Automatic Weather Station MAWS301 Update of the Hydrometeorological Real-Time Network in North-Eastern Italy Since the mid 1980 s Regione Emilia Romagna has been active in the provision of regional weather forecasts. The existing hydro-meteorological real-time network employs several technologies, ranging from Surface Weather Stations to Weather Radars and Radiosounding system. After several organizational changes over the years, the dedicated organization is today the Regional Hydro-Meteorological Service (SIM). SIM operates within the Regional Agency for Environment Protection (Agenzia Regionale Protezione Ambiente ARPA). The ARPA SIM headquarter and the Chief Prof. Stefao Tibaldi are located in Bologna and it is from there that the networks of automatic weather stations, the weather radars and the automatic radiosounding system are remotely managed. ARPA SIM has defined its mission as to: Manage networks of automatic weather stations and collect data in real time from the GTS network Process and distribute short notice weather forecasts, on a high resolution local scale and different time schedules Distribute, to a diversified number of users, specialized weather products (i.e. Teleneve and Icecast-Forecaster) Carry out climatological data processing to support studies of climatic changes on the regional level Tender requirements and award In the late summer of 2003, ARPA Emilia Romagna issued a call for tenders for the turn-key supply of 49 automatic weather stations, to upgrade and expand one of the existing surface observation networks. The automatic weather stations were divided into two types: 9 urban (configured to measure air temperature and humidity, wind speed and direction, rain and net solar radiation) and 40 agrometeorological stations (with different configurations to measure, depending upon the setup, air temperature and humidity, wind speed and direction, rain, globan solar radiation and leaf wetness). All 49 automatic weather stations were specified in the tender with enhanced characteristics such as full data logging configuration, GSM/GPRS data link and solar panel powering. In the tender it was stated that the contract would be awarded to the supplier able to offer the best equipment based on an evaluation of the price and technical specifications. In order to propose the most competitive offer in terms of a technical, logistical and pricing solution, Vaisala Hydromet bid the tender, as Prime, in co-operation with the Vaisala's long-time Italian representative, Eurelettronica Icas Srl. In December 2003, as a result of the tender award, Vaisala HydroMet signed a contract with ARPA Emilia Romagna marking the introduction of the Vaisala Automatic Weather Station MAWS301 to the Italian market. The MAWS301 features state-ofthe art technology for automatic weather stations in terms of sensor configuration, telecommunication and power supply. Specifications and installation of the Vaisala Automatic Weather Station MAWS301 The installations started in the early spring of 2004 in Piacenza, Parma, Reggio Emilia, Modena, Ferrara, Ravenna, Forlì, Cesena and Rimini all urban sites, with beautiful views of the downtown area. This posed several challenges in terms of installation constraints and tailor-made system layouts were defined for each site. The Vaisala Automatic Weather Station MAWS301, as delivered to ARPA Emilia Romagna, include the new Vaisala Data Logger QML201, a complete automatic weather station designed on one printed board. The board contains a 32-bit Motorola CPU for data processing and 10 differential (20 single end /2004

21 View from Reggio Emilia site. The urban location of the sites required tailormade system lay-outs to be carried out for each installation site. ed) analog sensor inputs (these can also be used as digital inputs). Moreover, there are three frequency sensor interfaces, a maximum of 6 serial ports, a 16 bit A/D converter, 1.7 Megabytes of secure Flash memory for data logging, as well as a power supply and charger for the internal backup battery. The board uses the latest SMD (Surface Mount Device) technology and is coated for improved protection in conditions of high humidity. The operation of the MAWS301 can easily be set-up and modified using the MAWS Lizard set-up program. The MAWS Lizard is a software program that instructs the MAWS301 as to what it should measure, log, calculate, and report. Measured data is stored in the daily log files that can be downloaded to a PC and viewed using the MAWS Terminal software. A basic setup is loaded in the MAWS program memory already at the factory. This allows the customer to simply connect the sensors, communication lines, and power supply to the MAWS301 and have the station start operating, making measurements, performing calculations and sending reports. The customer is able to freely reconfigure the setup files or make completely new ones, by using the Vaisala Set-up Software for MAWS. The MAWS301 is a low-power system and the logger consumes less than 10 ma from a 6 V battery. The system can be powered using a solar panel or optionally using a 110/230 AC power supply, if heated or optical sensors are used. The power consumption of the complete system depends on the sensors, communication devices, and other options included in the delivery. For example, the MAWS301 with a basic set of 5 sensors, each with a 10-minute measuring interval, has an average power consumption of 10 ma. A data link is provided with the iconnector ic101, a small adapter that enables installed devices to use the Internet for messaging via wireless modems and data-enabled phones that operate over AMPS, CDMA, CD- PD, GPRS, GSM, iden, and TDMA wireless networks. iconnector provides Instant Internet connectivity by eliminating the need for any hardware modification to a host device when connecting it to an Internet Service Provider (ISP). iconnector supports, for example, FTP client basic features and enables the user to communicate with the server using the FTP protocol. Vaisala has extensive experience in the design, manufacture, installation, commissioning and servicing of complete networks of automatic weather stations and networks, worldwide. Thanks to this diversified and large installation experience Vaisala has been able to develop the most enhanced technical solutions in terms of data communication, low power consumption and high sensor integration capability. Research and development of the Vaisala Automatic Weather Stations is continuously ongoing. 165/

22 Angela Billings Vaisala Helsinki, Finland Co-operation to improve water quality measurement The systems used to measure the quality and quantity of the water in Finland s inland waterways will be improved through the co-operation between Vaisala Oyj, the Finnish Environment Institute (SYKE) and the Uusimaa Regional Environment Centre. The objective of this co-operation is to develop measuring systems that will provide more accurate information on the leaching of nutrients into the waterways. It is expected that considerable sums of money will be saved with the automation of these measurements. The first stage of the project will last two years. The pilot stations will be located in Uusimaa, an area surrounding Helsinki. Vaisala, SYKE and the Uusimaa Regional Environment Centre have signed a co-operation agreement to develop solutions for improved water protection and water research. The aim is to develop measurement instruments and measuring sys- tems that will provide more accurate information on the leaching of nutrients into surface waterways. The instruments are also designed to determine what actions will best reduce the nutrient load in these waterways. The measurement instruments and solutions will also be applied to hydrological monitoring and its development. The target is to create a system by which sensors will provide users with topical information over a GSM network. The results of the project will be utilized in both national and international environmental monitoring and research. The co-operation between Vaisala, SYKE and the Uusimaa Regional Environment Centre combines the expertise of the environmental administration authorities and the private sector. Vaisala will manufacture and develop the measuring systems. SYKE will provide expert assistance by analyzing and evaluating the material, while the Uusimaa Regional Environment Centre will maintain the measurement stations and take samples. The three test stations involved in the project are located in Southern Finland. Eutrophication is the biggest problem in Finnish waterways. The nutrients released into them cause point and non-point pollution. Typical point sources of nutrients include industrial and municipal wastewater and fish farming. Non-point sources of nutrients include agriculture and forestry and wastewater in rural areas. Over half of the nutrients entering the waterways due to human action are from agriculture. Hydrological conditions affect the leaching and transportation of these nutrients /2004

23 Andy McDonald Regional Manager Vaisala Road Weather Birmingham, UK Norwegian Roads safer with Vaisala's Remote Measurement and Forecasting Technology The Norwegian Public Road Administration (NPRA) in Stor-Oslo District has the responsibility for procuring and managing contracts from the private sector for the provision of winter service on the national highway network in and around Oslo. The public policy is that national roads should be kept free from ice and snow at all times. This is a difficult task in Oslo's harsh winter climate, one which requires forward planning. Remote measurement and forecasting technology has a key role to play in determining the correct winter maintenance action. The importance of accurate, timely data being available 24 hours a day is one of the main reasons why the NPRA have chosen to contract with Vaisala in the UK for the provision of a complete data management service; a service which involves not only the supply of remote road weather stations but the responsibility for ensuring the continuous flow of data and forecasts to the NPRA's chosen winter service contractors around the clock. This service is made possible by utilising internet connectivity. A number of Vaisala weather stations are located at strategic points on the highway network around Oslo. These stations provide a continuous source of road weather information including details of the road surface condition and temperature as well as the general state of the atmosphere, for example visibility and type of precipitation falling. The information is automatically transmitted to Vaisala s data management hub (Bureau) in the UK where it is stored and processed in a relational database. Working in partnership with the Norwegian National Meteorological Institute (MI), a number of 24 hour forecasts are prepared each day for the strategic weather station points and also transmitted to Vaisala s UK Bureau for further processing and storage. Forecasts comprise a range of graphical and Norwegian text products tailored to the requirements of the NPRA. Each graphical forecast provides detailed information on the expected temperature and road condition for the coming night which can be directly compared against measured data from the weather station points. To complement the point forecasts, forecast thermal maps of the complete network are provided. These indicate which sections of road will fall below freezing and at what time, giving crucial information in sufficient time to take preventative salting action. Online solutions provide real-time weather station data and forecasts The NPRA have chosen to access the forecast and weather station data using a combination of web browser and application software. The web browser access is called IceWeb and is available to any of the NPRA s nominated contractors or personnel via the use of a password and Internet access. For key decision makers, a software application called Ice- View is loaded on to each nominated PC. IceView also makes use of the Internet to retrieve weather station data and forecasts from the Vaisala Bureau. In addition, IceView allows the user to manipulate the data and change configuration information in such a way as to tailor the information to specific areas. Service and calibration ensure continuous and accurate data Continuous and accurate data supply are two of the most important parameters for NPRA. To address these points the data management service incorporates a number of safeguards and monitoring functions. Prior to the start of winter each of the weather stations are serviced and calibrated by Vaisala and the process repeated during the course of the winter. Once the winter starts the Bureau is manned 24 hours per day, 7 days per week in order to provide a continuous backup and ensure a smooth operation. This is facilitated by duplicating all key points of failure such as Internet Service Providers and database servers. Every time a new piece of data is received by the data hub from a weather station it is automatically scrutinised for error and and any evidence of calibration drift. If an error does occur at any time Vaisala maintenance personnel are on constant standby ready to carry out repairs in a timely fashion and bring the station or sensor back online as quickly as possible. By utilising the Vaisala Bureau, NPRA in Stor-Oslo are able to delegate the responsibility of data management and concentrate on the core responsibility of managing the highway network. The partnership of NPRA, Vaisala and MI ensures that the driving public around Oslo are provided with a level of service which both they and the law demand. Vaisala's data management hub- The Bureau stores detailed information about road weather conditions. 165/

24 Timo Honkanen Development Manager Vaisala Aviation Weather Helsinki, Finland Work on the expansion of the Dubai International Airport has begun and will be completed in One new terminal and two concourses will be built which will almost triple the passenger capacity of the airport. Vaisala Upgrades Dubai International Airport In the beginning of 2004, Vaisala Aviation Weather delivered the new Vaisala MIDAS IV Automated Weather Observing System (AWOS) software to Dubai International Airport (DIA). It was a very demanding upgrade project at one of the most prestigious airports in the world. Dubai International Airport best in the Middle East Dubai International Airport was established in 1959 when the late Ruler of Dubai, HH Sheikh Rashid bin Saeed Al Maktoum, ordered its construction. Today, DIA is one of the fastest growing airports in the world. Furthermore, it is recognized as the aviation hub and busiest airport in the Middle East. In 2003, a total of 18 million passengers passed through the airport, a 13% growth in comparison to Dubai International Airport at present has the capacity to handle 22 million passengers annually. However, by 2010, 60 million passengers are expected to pass through the airport every year. With consideration of these figures, the Department of Civil Aviation began a second phase of expansion with a total investment of 4.1 billion USD in the first quarter of The expansion is scheduled to be completed by 2006 and will include the construction of a third terminal, two concourses and a new cargo terminal. Upon the completion of the second phase the Dubai International Airport will have the capacity to handle 70 million passengers per year. High standards of service are customary at Dubai International Airport. Readers of the magazine Business Traveler Germany have voted Dubai International Airport the Best in the Middle East and Africa in a recent survey and Condé Nast Traveler Magazine awarded the airport Best International Airport Worldwide in With this background, it was evident that a faultless world-class AWOS upgrade solution was the only acceptable option at Dubai. Software upgrade provides new functionalities The latest Vaisala MIDAS IV version 2.0 continues to provide International Civil Aviation Organization (ICAO) compliant AWOS to airports of all sizes. Backward compatibility is mandatory and therefore the existing Vaisala MIDAS IV configuration can be utilized in system upgrades. Also, the look and feel of the user interface remains the same to avoid any confusion for the users. One of the main new features is the possibility to use hotstandby functionality without any special hardware. This LANbased duplication allows Vaisala MIDAS IV servers to be installed anywhere in the network, not necessarily in the same rack. The LAN can be extended all the way to the sensor sites, making the system easily expandable. If remote connections are necessary, a new dial-up service can be used to send data to the desired remote locations. Further, a dial-up or secure Internet connection can be used for remote diagnostics or maintenance. The latest version of the Vaisala MIDAS IV includes an ICAO compliant runway friction application called SNOWTAM. SNOWTAM automatically sends data to weather reports on the friction values of the runway surface. Of course the weather conditions in Dubai do not require the use of SNOWTAMs. Vaisala MIDAS IV Automated Weather Observing System upgrade Dubai International Airport first installed the Vaisala MIDAS IV Automated Water Observing System in The primary task of the system at DIA is to provide real-time weather data to end users, and to generate weather messages such as METAR, TAF and SYNOP for the Aeronautical Fixed Telecommunications Network (AFTN). Vaisala MIDAS IV is a critical tool for MET office personnel as well as air traffic controllers. In addition, Midas IV provides data for the Automatic Terminal /2004

25 Information System (ATIS). From a technical point of view, the Dubai system is a largescale system, running in a cluster of two central data units for maximum reliability. End users can operate a number of Vaisala MIDAS IV workstations at various locations around the airport. In 2003 Dubai International Airport decided to upgrade the existing Vaisala MIDAS IV software to meet the latest ICAO specifications. Also, METAR, SYNOP and CLIMAT enhancements were needed together with some customization. Naturally, the airport was required to stay operational during the upgrade. Vaisala Software Engineer, Antti Tölli started preparation for this demanding project as the Project Manager in late Due to many new software requirements, Senior Software Engineer Hannu Heikkinen was also part of the project team right from the start. Senior Software Engineer Hannu Heikkinen and Project Manager Antti Tölli were responsible for the installation of the upgrade of the Vaisala MIDAS IV system at Dubai International Airport. A challenging installation requiring careful planning and co-operation The actual delivery of the system took place in February Thanks to careful preparation and co-operation with DIA personnel, the upgrade was completed on-site by Antti and Hannu in just two weeks! The first day on-site, Antti and Hannu met with the local AWOS team - Dave Thomas, MET Office Manager, Graham Orr, Electrical Engineer and Sony Antony, Maintenance Engineer. The group adjusted the implementation plan and schedule for the new software and hardware installations. Considering the overall system complexity and the number of flights landing and taking off from the airport, it was clear that the team was faced with a real challenge, as there was no allowance for system downtime. Dave Thomas, FRMetS CMet, Manager, Dubai Meteorological Office, Department of Civil Aviation stated that having worked with the MIDAS IV system for almost 5 years we had very clear ideas of how we wanted to customize the system to fit our exact requirements. This posed some testing problems for Antti and Hannu, as a result they worked some long days but they always came up with a solution in the end. A test system with the new hardware and software was set up next to the existing system in the equipment room. Special arrangements were made so that both the old and new systems were able to run parallel without any interference to the normal operations. After some fine-tuning of the new configuration, the system was ready for the Site Acceptance Tests (SAT). Thorough test procedures were carried out by the local AWOS team and after three days of intensive site acceptance testing, approval was given to the new system. The most critical moment of the upgrade was taking the new system into operational use. Careful preparations were made to ensure a smooth switch to the new system. The new computers and displays were moved into their positions and made ready to be plugged in. As afternoons are the quietest time at the Dubai International Airport, it Sheikh Rashid Terminal. was the best time to switch over to the new system. Once this was done the old computers and workstations were disconnected, the new ones connected and the data started to flow in immediately. During the hours following installation, the operation of all critical functions of the system were verified, including the ATIS and AFTN interfaces. Promising future The project was a success. The new system is up and running and the customer is satisfied. New technical features introduced proved to be useful and robust, such as the LAN based duplication. Support for LANbased sensor communication is already implemented in the Vaisala MIDAS IV. Whenever DIA decides to convert serial line connections into full use of TCP/IP and fiber optics, Vaisala MIDAS IV will be ready to support the conversion. The co-operation between Vaisala Aviation Weather and DIA continues and over the course of the next few months, a new graphical tool and database for various data mining needs (the automatic extraction of hidden information from databases) will be installed to the current system. Dave Thomas, FRMetS CMet, Manager, Dubai Meteorological Office, Department of Civil Aviation commented that the new system has many improvements and some customizations that have simplified our operational procedures. We will continue to work with the MIDAS IV team and look forward to future developments. The future for the Vaisala MIDAS IV Automated Weather Observing System seems very promising. The upgrade of the Dubai International Airport is once again further proof that Vaisala MIDAS IV continues to be the most advanced and versatile automated weather observation system available. Many new ideas and innovative solutions are being developed and put into practice by the Vaisala MIDAS IV system architects which will be available to our customers in the near future. 165/

26 Angela Billings Vaisala Helsinki Finland Vaisala Invests 6.5 million Euros in New Clean Room Vaisala's new clean room was taken into operation and production of Vaisala's sensors was re-started in May The new facility is state-of-the-art and one of the few clean rooms in private ownership in Finland. In May, 2004 Vaisala's new clean room was taken into operation. The facility is one of the most modern in Finland and one of the few clean rooms in private ownership. The new space is 500 m2 and 1/6 of the space is in accordance with the ISO 5 standard while the remaining 5/6 are in accordance with the ISO 6 standards. The total investment cost of the facility was 6.5 million Euros. Most of the equipment from the previous clean room will be moved into the new facility and production will begin immediately. Vaisala's sensors are manufactured in the clean room, a nearly particle-free environment with no more than 1,000 particles larger than 0.5 microns in any given cubic foot of air. The yellow light in one section of the clean room protects the photosensitive layer of wafers from excess of UV-light. In this section patterns are formed on wafers by UVexposuring the photosensitive resist through a mask. More than 20 years of clean room experience Vaisala is one of the few private companies in Finland to own and operate a clean room. The previous facility was taken into operation in 1981, and built to manufacture integrated circuits for radiosondes. In the 1990's production was concentrated to the manufacturing of sensors for Vaisala Radiosondes as well as the HUMICAP and BARO- CAP. The need for additional space and a modernization of the After every production step, the sensor-wafers are carefully checked e.g. by a microscope inside the clean room before further processing. In wet etching the wafers are dipped in chemical baths to achieve metal removal from desired parts of the wafer /2004

27 What is a clean room? Aclean room is an area where air quality, temperature and humdity is carefully regulated to ensure that senisitive equipment is protected from any possible contamination. The air in the room is continuously filtered using HEPA filters to remove any dust particles or other impurities which could damage any highly sensitive materials being produced or worked with. In the ISO 5 standard pat of the room the air is circulated/changed 400 times per hour and in the ISO times/hour. All staff working in a clean room must wear special protective clothing called "bunny suits" to ensure that no fibers, hair or skin are added to the room's atmosphere. The International Standards Organization (ISO) has set standards for the number of particles allowed per cubic foot of air. The Vaisala Clean Room is in accordance with the ISO 5 and ISO 6 standards which means that in any cubic foot of air there are no more than 100 (ISO 5) or 1,000 (ISO 6) particles larger than 0.5 microns. The row of wet benches are used to wet etching, resisit removal and cleaning of wafers. exisiting room lead to the decision to invest in the new facility. The clean room is used to manufacture sensors for internal use as well as for product development and research. The ability to manufacture sensors internally ensures the high quality of Vaisala's sensors. Annually, approximately 900,000 sensors are produced in the clean room. The majority of these sensors are used in Vaisala Radiosondes, but a portion of them are also used in Vaisala's humidity and pressure products. The investment in the new clean room will ensure that Vaisala's customers will continue to receive high-technology products providing relaible and accurate measurements. The wafers are placed inside an oven and heated to 300 degrees Celcius in order to harden the thin polymer layer. The number of particles in the air are monitored regularly in order to ensure that they are kept within the proper range. 165/

28 Angela Billings Vaisala Helsinki, Finland Secretary General of the World Mete Mr. Michel Jarraud, Secretary-General of the World Meteorological Organization (WMO) visited Finland on one of his first official visits to a member state since taking up the post as Secretary-General in January. Mr. Jarraud views Finland as an appropriate first visit since it is an important partner and active member of the WMO, very active in the industrial sector and a partner in supporting developing countries. His visit was arranged by the Finnish Meteorological Institute and included a visit to Vaisala where Mr. Pekka Ketonen, President and CEO of Vaisala gave a presentation of Vaisala and a tour of the production facilities and the new clean room. Pekka Ketonen, President and CEO of Vaisala shows Mr. Jarraud, Secretary General of the WMO how the Vaisala Radiosondes are produced. Vaisala News had the opportunity to speak to Mr. Jarraud and hear his views on the future challenges facing his organization, weather in general and the the role private organizations such as Vaisala will have in the future. The WMO falls under the umbrella of the United Nations (UN) with a membership of 187 member states and territories. It was established in 1950 and is the specialized agency of the UN for meteorology, including weather and climate, operational hydrology and related geophysical sciences. The WMO is the UN's authoritative voice on the status of the world's atmosphere including how it interacts with the oceans and affects the climate. Vaisala is an important provider of equipment used to collect the necessary measurement data of a wide variety of weather parameters used by many of the national weather services around the world. Natural disaster prevention, an important development area Weather has become increasingly important on the international agenda in recent years with much focus being placed on climate change and natural disasters. Mr. Jarraud believes that we are living in an exotic time where nature impacts all areas of human activity. He says "the prevention of natural disasters is important for developed countries and even more important for developing countries who are generally more vulnerable to these phenomenon. Approximately 80% of disasters are meteorological or hydrological." He believes that disaster prevention will be a top priority for the future as the countries shift towards disaster preparedness rather than disaster relief. Mr. Jarraud believes that climate change will become an increasingly important area for the WMO to focus more on in the future. The WMO is playing an important role by co-ordinating high-standard observational networks and ensuring that data and products are shared freely on a global level. These networks are showing a change in the earth's climate which will have /2004

29 orological Organization visits Vaisala impacts on many facets of human life. Challenges facing the WMO in the future Mr. Jarraud believes that an important and major challenge facing the WMO is the co-operation between the WMO and national weather services, NGO's, local authorities and private organizations. He feels that there is a need for a new approach to cooperation and a need to develop an aggressive policy to communicate weather-related issues. There will be a need to ensure that the gap between the developed and developing countries is decreased and increasingly there will be a need to develop good models to involve private organizations in the WMO's activities. Differences between member states Another area, which will pose a challenge to the WMO in the future, is the gap between the developed countries and the developing countries. Decreasing this gap has been a priority for the WMO for many years now and Mr. Jarraud believes that new technology can bridge this gap. The less developed countries will need access to products, information on the use of products and training and education in order to catch up to the more developed countries. Currently the major obstacle in many countries is the cost of data as it is difficult to maintain the quality of data at a low cost. Mr. Jarraud states that many countries have a hard time to meet the monetary needs needed to obtain quality data. This can be a question of a need for better-trained personnel to a need for financial resources. He believes that private organizations will have an important role to play in finding ways to lower the cost of equipment. The role of private organizations in the WMO All member countries have representatives from their national meteorological services in the WMO, however, private organizations are becoming increasingly involved today. Mr. Jarraud states that Vaisala is one of the more involved private organizations today. He continues to say that the provision of services by private organizations is evolving and developing and that there will be a need for the WMO in the future to find mechanisms to interact with the private sector even more on the local, national, international and WMO level. The instrument organization that Vaisala is co-operating in may be used as a model for other areas as well. There is a need to try and possibly use different models to co-operate with the private sector on. Co-operation with Vaisala The Vilho Väisälä prize was established in 1985 and is administered by the WMO to encourage and stimulate interest and support in important research areas which support the WMO's programs in the field of meteorological and climatic observation methods and instruments. Mr. Jarraud sees the award as a very visible and prestigious prize. Vaisala and the WMO are currently looking into ways to further develop the award and new directions are being explored. Mr. Jarraud stated that the cooperation between the WMO and Vaisala has been very valuable to the WMO and that he looks forward to continuing this in the future. Jan Hörhammer of Vaisala shows Mr. Jarraud a sensor which has been produced in Vaisala's clean room. Mr. Ketonen explains how the Vaisala Radiosondes are calibrated. 165/

30 Angela Billings Vaisala Helsinki Finland In Vaisala Thirty years of Excellence in Humidity Measurement Thirty years ago Vaisala presented a completely new way of measuring humidity. Vaisala HUMICAP Sensor, the world's first thin-film capacitive humidty sensor was brought onto the market. Three decades later Vaisala has become the world market leader in the measurement of relative humidity and kept its place as a pioneer in the development in state-of the art humidty instruments. More information can be found on Annual Results for 2003 Released V aisala's net sales for 2003 totaled EUR million and the operating profit of the Group was EUR 25.9 million. Growth in demand stopped in early 2002 and has been unstable across all business areas. Despite this situation the company's operating profit grew by 14.7% compared with The improved result, depsite lower net sales, can be attributed to measures to improve profitability. These measures will have full effect in Vaisala is listed on the Helsinki Stock Exchange (HEX). For more information or to read the Annual Report for 2003 please visit com/annualreport Vaisala to sponsor the 18 th International Lightning Detection Conference The International Lightning Detection conference will be held in Helsinki the 7th to the 9th of June The conference theme will be New Understanding of the Relationships and Impacts of Lightning: Improving Real-world Applications with Advances in Detection Research and Data Integration. The ILDC, a biannual conference, provides a unique and important forum for presentations and discussion related to education, research, and applications development in lightning detection technologies. ILDC presenters and attendees share a common passion for understanding lightning and how it affects the world we live in. Professionals in the fields of aerospace, atmospheric research, aviation, data center management, emergency response management, electrical engineering, electric power, explosive and ordnance management, forestry, golf and recreation, lightning research, meteorology, mining, telecommunications and weather media are invited. European Meteorological Annual Meeting The 4th Annual Meeting of the European Meteorological Society (EMS) will be held September 26-30th in Nice, France. Vaisala will participate in the meeting and will organize a customer workshop during the week to present Vaisala's new products such as the Thunderstorm Information System and the Vaisala Soundings division's equipment for upper air weather observations. Additional information about Vaisala's workshop can be found on & Events and more information on the EMS annual meeting can be found at Mesoscale workshop held in Boulder V aisala co-organized a workshop entitled Design and Development of Multi-functional Mesoscale Observing Networks in Support of Integrated Forecasting Systems in December. The goal of the workshop was to develop recommendations and identify areas for continued research and development of improved mesoscale observing systems. These developments will be based on the needs of users, modelers (including those engaged in data assimilation), and forecasters. The focus was placed on identifying the challenges, needs and opportunities involved in the development of improved, economically viable, integrated atmospheric mesoscale observing, modeling and information-delivery systems. The potential users of these systems include federal, state and local agencies in addition to private weather information providers and end-user groups. A consensus has emerged within the observational, modeling and forecasting communities that carefully designed, integrated mesoscale systems will improve short-term forecasts in the future. To realize the full benefits of enhanced forecast modeling there is a need to improve the high-resolution observations of all meteorological variables, in addition to improvements in data assimilation, model physics, parameterizations, and end-user-specific analyzes and forecast products. Improved mesoscale systems yield improved short term forecasts Improved mesoscale systems are able to deliver forecasts of the physical and chemical state of the atmosphere including precipitation, ground state and run-off. These systems provide accurate, timely and user-relevant forecasts useful for improved short-term forecasts of severe weather, flash flooding for the use of water management, energy production and management, agriculture, air quality, homeland security and public health to name a few. Next steps The workshop was organized in joint cooperation between Vaisala, the University of Oklahoma and the NOAA Forecast Systems Laboratory. The formal report summarizing the findings and recommendations from the /2004

31 workshop will be available at the end of April and will be reported in the next weather observation issue of Vaisala News. Additional information on the workshop can be found at uswrp/upcoming_meetings/ announcement2.html Vaisala Aviation Weather participates in ATC Maastricht 2004 V aisala's Aviation Weather participated in ATC Maastricht February 10-12, Maastricht is the annual meeting place for the leading ATC (Air Traffic Control) and ATM (Air Traffic Management) industry global suppliers. Vaisala Aviation Weather displayed solutions for aviation weather observations and introduced several new products including the new tranmissometer for runway visual range assessment, the new ceilometer for cloud height measurements and vertical visibility measurements. Vaisala arranged an Aviation Weather Seminar in conjunction with the exhibition. An overview of the present and future developments in the Vaisala Aviation Weather unit was presented and a group of experts discussed the latest products in the industry covering a wide array of items spanning from sensors to service contracts. Mr. Pekka Utela from Vaisala presented a paper entitled Sales Managers Kim Kaijasilta and Ingo Schesonka present Vaisala Aviation Weather to customers at the Vaisala stand. Specifying visibility and cloud instruments. The presentation covered current technologies for cloud and visibility measurement as well as international standards for measurement performance. Particular focus was placed on the key performance areas that are currently not adequately covered by common standards as well as suggestions for improving the methods of specifying cloud and visibility instruments were suggested. The three day show attracted more than 2,800 visitors from approximately 80 countries. Most of the participants are from civil aviation authorities, governmental departments, air navigation providers, airports and airport authorities and it is a unique opportunity for the major supplier of air traffic control equipment, training and communications to meet their customers. Klaus Heyn of Vaisala presents the new Vaisala Transmissometer. 165/