Spring School Land use and the vulnerability of socio-ecosystems to climate change: remote sensing and modelling techniques GIS and Remote Sensing Katerina Tzavella Project Researcher PhD candidate Technology Arts Sciences TH Köln Technische Hochschule Köln Institute of Rescue Engineering and Civil Protection Betzdorfer Straße 2 50679 Köln T: +49 221-8275-2354 F: +49 221-8275-2202 E-Mail: katerina.tzavella@th-koeln.de Web: https://riskncrisis.wordpress.com/the-team/tzavella_katerina/
Overview GIS Geographical Information Systems Raster data Vector data DEM (Digital Elevation Model) Satellites Remote Sensing
What is G I S? Geographic + Information + Systems
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Store Information Analyze Visualize Plan Collect More Map Decision Making GIS Is an organised collection of : 1. Hardware 2. Software 3. Network 4. Data 5. Procedures and 6. People!
With GIS : put important information of the real world Geographical features on maps
Representing Geographical Features How do we describe geographical features? by recognizing two types of data: Spatial data which describes location (where) Attribute data which specifies characteristics at that location (what, how much, and when) How do we represent these digitally in a GIS? by grouping into layers based on similar characteristics and using either: Vector Data Raster Data
Representing Geography The discrete object view represents the real world as objects with well defined boundaries in empty space (vector data) country borders land parcels locations streets (x 1,y 1 ) Points Lines Polygons The field view represents the real world as a surface divided into a regular grid of cells. They are continuous surfaces of data. (raster data) aerial photograph a satellite image a surface of chemical concentrations an elevation surface.
Raster data are described by a cell grid, one value per cell Vector Raster Point Line Polygon Zone of cells
Raster and Vector Data
Information is organized into layers Rivers Cities Lakes Roads States 17
Many ways to use GIS in the real-world! Energy Forecasting Agricultural Efficiency Carbon Management Aviation Safety Homeland Security Community Growth Disaster Management Public Health Coastal Management Invasive Species Water Management Air Quality
What is Remote Sensing? Remote sensing (RS) is the collection of information about an object without being in direct physical contact with the object. 1. Energy Source or Illumination (A) 2. Radiation and the Atmosphere (B) 3. Interaction with the Object (C) 4. Recording of Energy by the Sensor (D) 5. Transmission, Reception and Processing (E) 6. Interpretation and Analysis (F) 7. Application (G)
Electromagnetic Radiation (EMR) Light - can be thought of as a wave in the 'electromagnetic field' of the universe Wavelength Frequency (how many times peak passes per second) A wave can be characterized by its wavelength or its frequency Remote sensing is concerned with the measurement of EMR returned by the earth s natural and cultural features that first receive energy from the sun or an artificial source such as a radar transmitter.
Electromagnetic Radiation (EMR) Because different objects return different types and amounts of EMR, the objective in remote sensing is to detect these differences with the appropriate instruments (sensors). This makes it possible for us to identify and assess a broad range of surficial features and their conditions. The Electromagnetic (EM) Spectrum
Sensors
Sensors Passive sensors Landsat ASTER Quickbard Ikonos Active Sensors LIDAR RADAR
Platforms Platforms are: Ground based Airborne Spaceborne Sensing from 1 meter to 36,000 km height
Aerial Camera Multispectral Satellite Radar Satellite (SAR) Hyperspectral Sensor Landsat/Ikonos/Quickbard Hyperion
Application of Remote sensing Urbanization & Transportation Updating road maps Asphalt conditions Wetland delineation Agriculture Crop health analysis Precision agriculture Compliance mapping Yield estimation 22
Natural Resource Management Habitat analysis Environmental assessment Pest/disease outbreaks Impervious surface mapping Lake monitoring Hydrology Landuse-Landcover monitoring Mineral province Geomorphology Geology National Security -Targeting - Disaster mapping and monitoring -Damage assessment -Weapons monitoring -Homeland security -Navigation -Policy 23
What is a Digital Elevation Model (DEM)? Devil s Tower in Wyoming
a. By digitizing contours This is a second hand digital, as contours are abstract and may result in artifacts in the model. b. Digital stereo photogrammetry This is a better option, as it refers to the real surface captured from aerial photographs. b. Direct image grid DEM from satellites / radars U.S. Releases Enhanced Shuttle Land Elevation Data through the Shuttle Radar Topography Mission SRTM DEM creation
Shuttle Radar Topography Mission SRTM The Shuttle Radar Topography Mission produced the most complete and highest resolution digital elevation model of the Earth. The project was a joint endeavor of NASA, the National Geospatial-Intelligence Agency, the German and Italian Space Agencies, and flew in February 2000. It used dual radar antennas to acquire data processed to digital topographic data of very good resolution.