Project Brief LiDAR for the North East

Transcription

1 Project Brief LiDAR for the North East Robert Kelly Michael Smith Mike Shillenn

2 Webinar Agenda LiDAR Basics Project Background Project Benefits Supported Applications Project Manager Work Plan Deliverables Accuracies Schedule

3 LiDAR Basics Airborne Light Detection And Ranging Very fast, accurate and cost effective technology to measure and quantify reflective surfaces (elevations) Systems Components Aircraft Crew (Pilot & Instrument Operator) Laser w/ mirror Uses its own energy source (NIR red laser) Direct (active) acquisition of terrain Allowing day or night operation GPS Receivers (Aircraft & Ground) Provides aircraft position Inertial Measurement Unit Provides aircraft orientation & direction Post Processing Software & Specialized Technicians

4 LiDAR Basics Mirror sweeps laser beam across the ground. Range to target is determined by measuring time interval between transmission and return of reflected laser pulse. Aircraft position is determined using GPS phase differencing techniques. Pointing direction of laser determined with Inertial Measuring Unit (IMU) and recording of mirror position. Data streams recorded and synchronized for post processing.

5 LiDAR Basics LiDAR is indiscriminate Target must be visible- it s not an all weather sensor Does not see through trees but around them It is not imagery but can be shaded to look like imagery High absorption rate of laser energy in water and new asphalt (no reflection) Newer systems can collect 167,000 elevation points per second! Capable of vertical accuracies of 10 cm RMSE or greater Does not automatically identify break lines Ability to collect multiple returns (4 or more) with both range (elevation) and intensity Multiple returns allows reflective surface mapping as well as creation of bare earth models

6 LiDAR Basics

7 LiDAR Basics USGS DEM LiDAR DEM

8 LiDAR Basics

9 Project Timeline Fall UNH proposal covering watersheds in NH and ME developed Spring 2009 ARRA funding indicated, project idea grows to New England Summer 2009 Northeast coalition (NY added) grows and starts gathering support and match funding Fall 2009 details come together and states draft ARRA proposal, with MEGIS as principal investigator Nov Lidar for the Northeast Proposal submitted to USGS, $2.7M total budget, $1.4M requested from ARRA funding January 2010 Award letter announces full funding of the project Spring/Summer 2010 Additional funding brought forward to further increase project footprint and products June 2010 first task order issued for ARRA-funded portion to PhotoScience September 2010 second task order issued for all other funding portion to PhotoScience Final project is approximately 8,000 sq miles of new data

10 Project Coordination Each state worked through it s state coordinator for non-profit and statelevel funding and requirements USGS liaisons coordinated other federal contributions Maine state coordinator worked with each state coordinator to bring the state and nonprofit portions together Maine s USGS liaison worked with other regional USGS liaisons to bring the federal portions together NGTOC handles contracting through Geospatial Products and Services Contract v2 (GPSC-2)

11 Project Funding States Federal Others Maine USGS- National & Local Nature Conservancy New Hampshire NRCS- State & Regional Maine Coast Heritage Trust Massachusetts FEMA Maine Geolibrary Rhode Island US DOT Maine DEP and Maine SPO Connecticut National Park Service University of NH New York NH DES NY DEC NY Energy Research Dev. Authority

12 Project Background Project Endorsers EPA- Region 1 US Fish & Wildlife NOAA CSC NRCS NDEP NROC National Park Service Passamaquoddy Tribe at Pleasant Point County of Cumberland, Maine Greater Portland Council of Governments Portland Area Comprehensive Transportation System City of Ellsworth, Maine Town of Hampden, Maine Town of Swans Island, Maine Town of Windham, Maine Hancock County Planning Commission Maine Building Officials and Inspectors Association Island Institute Friends of Casco Bay / Casco Baykeeper Wells National Estuarine Research Reserve Maine GIS Users Group Maine Real Estate & Economic Dev. Assoc. Maine Assoc. of Realtors James W. Sewall Company Spatial Alternatives Inc Maine Community Association of Banks University of Maine University of Southern Maine City of Boston Old Colony Planning Council Southeastern Regional Planning & Economic District Metropolitan Area Planning Council Mass Audubon Mass River Alliance Rhode Islands Coastal Resource Management Council Coastal Institute University of Rhode Island Stormwater Coalition of Albany County

13 Project Benefits Economy stimulus for collectors/providers, analysts, engineers, planners, scientists, consultants, etc. Multi-state and federal collaboration, exemplifying good government and model for the national elevation program A coordinated collection and processing effort will result in real tax payer savings (map it once, used by many) Data freely available to general public ( via USGS CLICK)

14 Supported Applications Floodplain mapping / Emergency preparedness Transportation planning Coastal and natural resources planning Forestry & wildlife mapping Land cover mapping/feature Extraction Wireless internet propagation Green energy development (wind farm siting) Orthophoto rectification Modeling Runoff Shoreline change (Sea Level Rise) Air mass Bio mass 3-D Modeling

15 Project Manager: USGS NGTOC The U.S. Geological Survey National Geospatial Technical Operations Center (NGTOC) provides essential support for the acquisition and management of trusted geospatial data, products, and services, through world-class geospatial technical expertise and customer service, for the USGS and the Nation. NGTOC supports The National Map (TNM) and the National Atlas of the United States, among other related efforts. Task Order Administration Task Order Management Client/Producer Liaison Technical Domain Expertise Independent Quality Assurance Testing Deliverable Validation & Acceptance Data Dissemination

16 Work Plan Project Specifications: USGS Base LiDAR Specifications Version 12 & Task Order Detail Project Initiation Internal External Procedures Manual Quality Plan Finalize Flight and Control Plans Flight coverage Base station locations (PACS, SACS, CORS) Ground & QA check point control locations Flight Operations Phase LiDAR Processing Phase LiDAR Post Processing Phase Delivery Phase

17 Work Plan: Total Project Area: 8,170 sq. miles States of: ME - 2,893 sq. miles NH sq. miles MA - 2,022 sq. miles RI - 1,074 sq. miles CT sq. miles NY sq. miles

18 Work Plan: Nominal Post Spacing* (NPS) Requirement NPS 1 meter (pink) 3,096 sq. miles MA & RI Higher point density Improved surface definition Larger file sizes NPS 2 meters (purple) 5,073 sq. miles ME, NH, CT, NY * Average ground spacing between LiDAR postings

19 Work Plan: Vertical Accuracy Requirement 9.25 cm vrmse (gold) 403 sq. miles Barnstable County, MA Higher vertical accuracy NSSDA AccuracyZ 95% = 18 cm Open terrain 1 foot contour capable 15 cm vrmse (green) 7,767 sq. miles Everywhere else NSSDA AccuracyZ 95% = 30cm Open terrain 2 foot contour capable

20 Work Plan: Tide Coordination Collection Requirement Daily Predicted Low Tide ± 90 minutes 326 sq. miles Coastal Massachusetts Spring Tides Avoid Neap Tides* windows of Oct 14-22, Nov 12-19, Dec Night flying also requested Neap tides occur at the quarter phases of the moon approximately midway between the new- and full-moon phases. At these moon phases, the gravitational forces of the sun and moon are perpendicular to one another and cancel each other out. Neap tides will typically have the least tidal range during the lunar month.

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22 Work Plan: Aircraft/Senor Configuration Pilot & sensor operator configuration Cessna U-206(s) 2- Leica ALS 50 II s max pulse rate of150 KHz, multi-pulse 3- Optech Gemini ALTM max pulse rate of 167 KHz, multi-pulse Applanix POS/AV DG Systems Trimble 7500 dual frequency GPS receivers (base stationing) Calibration home base & local Horizontal: UTM Zones 18 & 19, NAD83, meters Vertical: NAVD88, Meters (most recent Geoid model approved by the NGS)

23 Work Plan: Collection Parameters North East LiDAR Project (Task Orders G10PD01027 and G10PD02143) Generalized Collection Parameters by Required Vertical Accurcay/Post Spacing* 15cm RMSE, 2m NPS 15cm RMSE, 1m NPS 9.25 cm RMSE, 1m NPS Flying Heigh (AGL) (Feet) Aircraft Ground Speed (knots) Pulse Rate (KHz) Scan Rate (Hz) Full Field of View (degrees) Multi-Pulse Yes Yes No Full Swath Width (meters) / Swath Overlap (percentage) 30% 30% 30% Max. Point Spacing Across Track (meters) Max. Point Spacing Along Track (meters) Across Track/Along Track Ratio Average Point Density (meters^2) Average Point Area (meters^2) Average Point Spacing (meters) 0.71m 0.57m 0.45m Nadir Pint Density (pts/meter^2) Illuminated Foot Print Diameter (meters) * Collection parameters for individual collection blocks may vary based on final flight plan, local terrain, land/water cover, tide requirements, etc. * Final LiDAR flight plans with collection parameters will be submitted to USGS prior to collection activities.

24 Work Plan: Collection conditions Collection Window: Fall 2010/Winter 2011 (24/7) Atmospheric Conditions: Cloud & Fog free between aircraft/sensor and ground Ground Conditions: snow free, no excessive flooding Vegetation Cover: Leaf Off Data Voids: not acceptable unless caused by water absorption, low infrared reflectivity (i.e. asphalt, composition roofing, or where filled in another flight line swath Base Stationing: kilometers max. baseline distance from CORS/NGS points

25 Work Plan: Collection conditions: Leaf Drop Source: The Foliage Network

26 Work Plan: Flight & Base Station Control Plan for Maine Collection Areas

27 Work Plan: Flight & Base Station Control Plan for New Hampshire Collection Areas

28 Work Plan: Flight & Base Station Control Plan for Massachusetts Collection Areas

29 Work Plan: Flight & Base Station Control Plan for Rhode Island Collection Areas

30 Work Plan: Flight & Base Station Control Plan for New York Collection Areas

31 Work Plan: Ground Control James W. Sewall & Company Survey Crews to obtain two types of control points: 215, supplemental GPS ground control points to check and validate ground classification during post processing phase 120, GPS QA check points established in open terrain to validate FVA accuracies by USGS QA Staff. These points NOT used by Photo Science in its workflow.

32 Work Plan: LiDAR Processing Process unclassified return point cloud in.las format V1.2 for each 1500m x 1500m tile that contains: The return number for each signal Horizontal and Vertical Position (x,y,z) in the specified horizontal and vertical datum Intensity return values for each return signal GPS Timestamp of capture for each point

33 IWork Plan: LiDAR Processing Intensity Image: Androscoggin County, ME

34 Work Plan: LiDAR Processing Additional automated and manual processing to classify point cloud in.las format V1.2 for each 1500m x 1500m tile that contains the following classes: Unclassified (non-ground) Class 1 Ground (bare-earth extra points) Class 2 Noise (low or high, manually identified, if needed) Class 7 Water- Class 9 Ignored Ground (Breakline Proximity) Class 10

35 Work Plan: LiDAR Processing Photo Science s classification/filtering workflow: is utilized to process the multi-return digital surface model (DSM) dataset to bare earth conditions is based on project specific terrain, vegetation density, and development (urban, suburban, and rural) conditions utilizes Terra Solid (TerraScan and TerraModeler) and GeoCue software, coupled with proprietary filtering routines typically results in the non-ground classification of approximately 75% - 80% of the above-ground (non-bare earth) DSM data points includes supplementing automated terrain filtering with interactive processing to achieve bare earth conditions.

36 Androscoggin County Orange- Ground, Class 2 Green- Vegetation, Classes 3/4/5 Dark Blue- Buildings, Class 6 Light Blue- Water, Class 9

37 Work Plan: LiDAR Processing Photo Science s classification/filtering workflow typically results in: minimum performance for artifact/feature classification from the bare earth surface model: 95% artifacts classified 95% outliers classified 95% of vegetation classified 98% of buildings classified dense vegetation data voids will be minimized by automated and manual removal process data which is not bare earth will not be filtered to reduce the point density. unfiltered data will maintain the initial Points per Square Meter hydrographic break lines will be used to classify hydrography features (hydro flattening) during post processing phase

38 Work Plan: LiDAR Post Processing Photo Science s post processing phase will include: Hydro break line development Hydro Flattening Bare Earth DEM development Version 12 specs

39 Work Plan: LiDAR Post Processing Hydro Flattening (Version 12 Spec) Approach maintains consistent character of National Elevation Model (NED) as a traditional DEM Typically accomplished through the use of breaklines Represents the ground surface as viewed from a top down perspective Natural depressions and road fills over culverts are desirable Hydrologic analysis applications typically require alternative approaches including hydro-conditioning and hydroenforcement Hydro Conditioned- flow of water is continuous across project area Hydro Enforced- drainage feature specific, enables H&H model to depict unimpeded flow of water through artificial barriers (bridges and culverts)

40 Androscoggin County

41 Work Plan: LiDAR Post Processing Version 12 Hydro Flattening: Hydro Break Line Development Develop hydro breaklines for inland ponds, lakes, streams, rivers, non-tidal and non-tidal waters using LiDAR intensity images and bare earth surface Inland ponds & lakes ~2 acres or greater (~350 diameter) Flatten and level water body (single elevation for every vertex) Water edge elevation will be just at or below surrounding terrain Reservoirs, inlets, fjords whose surface elevations drop moving downstream will be treated like rivers

42 Androscoggin County

43 Work Plan: LiDAR Post Processing Version 12 Hydro Flattening: Hydro Break Line Development Inland Streams & Rivers Collect only if 100 nominal width or wider Flat and level bank to bank with gradient following immediately surrounding terrain Water surface edge at or just below surrounding surface Break at roads crossings (culvert locations) Do not break at bridge crossing Bridge to be removed from ground surface

44 Work Plan: LiDAR Post Processing Version 12 Hydro Flattening: Hydro Break Line Development Non Tidal Boundary Waters Represents the edge(s) of project area, opposing shore not required Water surface edge at or below surrounding terrain Elevations will be consistent along the edge(s) having single elevation (lake) or gradient (river) Tidal Boundary Waters Oceans, seas, gulfs, bays, inlets salt marshes, etc affected by tidal variations Breakline discontinuities along shorelines are normal and expected Final DEM should include as much ground as collected data permits Variations in water surface elevations caused by tidal variation across project area will not be removed or adjusted

45 Work Plan: LiDAR Post Processing

46 Work Plan: LiDAR Post Processing DEM Development Develop 3 meter gridded DEM from final, hydro flattened bare earth surface for each 1500m x 1500m tile DEM s will be edge joined and seamless with project areas Void/suspect flag will not be used Data source date will be the latest date the LiDAR was acquired Delivered in ERDAS.IMG format Georeferencing in raster file: UTM 18 or 19, NAD83 & NAVD88, Meters

47 Deliverables 1. All Return Data (raw point cloud data) Delivered by flight swath (< 2GB) in.las version 1.2 Georeferenced Intensity values GPS timestamp All points delivered 2. Fully Classified Point Cloud 1500m x 1500m tiles, no overlap,.las version 1.2 Classes 1, 2, 7, 9 & 10 Hydro flattened Georeferenced GPS Time Stamp Intensity values 3. Raster Bare Earth DEM 3 meter cell size ERDAS.img format Georeferenced 1500m x 1500m tiles No edge artifacts or mismatched Void areas code with Nodata value Depressions (sinks) not to be filled Hydro Flattened 4. Hydro Breaklines (shape files) 5. Project Reports 6. Metadata- Project, Lift and Product Group

48 Accuracies Two Fundamental Vertical Accuracies (FVA) based on collection area : 1) Bare earth TIN will be 30 cm at a 95% confidence level, derived according to NSSDA, i.e., based on RMSE of 15 cm in the open terrain land cover category. 2) Barnstable County- Bare earth TIN will be 18 cm at a 95% confidence level, derived according to NSSDA, i.e., based on RMSE of 9.25 cm in the open terrain land cover category.

49 Progressive Schedule Fall, 2010 February 28, 2011 April 1, 2011 May 2, 2011 June 3, 2011 July 1, 2011 Begin data collection ¼ of all project deliverables due ¼ of all project deliverable due ¼ of all project deliverables due ¼ of all project deliverables due All remaining project deliverables due* *Statewide data sets will be organized and delivered once acceptance of each state s dataset has occurred and will include boundary tiles shared between states

50 Contact Information Michael Smith State GIS Manager, Maine Office of GIS, Maine OIT State House Station Civic Center Drive (207) Robert Kelly, MS 668 USGS/NGTOC 1400 Independence Road Rolla, MO (573) Michael Shillenn, CP Photo Science 104 S. Church Street West Chester, PA