Landsat Calibration Through Ground Truth and Modeling Kyle A. Foster Digital Imaging and Remote Sensing Laboratory Chester F. Carlson Center for Imaging Science Rochester Institute of Technology 11 August 2006
Digital Imaging and Remote Sensing Laboratory August 11, Landsat primer Thermal calibration overview Overpass collect locations Collection process Data Processing Modeling Results Questions Outline
Digital Imaging and Remote Sensing Laboratory August 11, What is Landsat? Longest continuing project for collection of Earth imagery (1972-present) Publicly available imagery Constantly updated Currently near-total Earth coverage (81º N to 81º S) Two operating satellites: Landsats 5 & 7
Digital Imaging and Remote Sensing Laboratory August 11, Who uses Landsat? Agricultural firms Environmental management organizations Geologists Oceanographers Geographers Remote sensing community Intelligence community
Digital Imaging and Remote Sensing Laboratory August 11, Landsat 5 Launched in 1984 Altitude 705 km (438 mi) 16-day coverage cycle Thematic Mapper (Vis & IR) 120 m thermal IR resolution Three year projected lifespan (and still going…) dd/Landsat-5.jpg
Digital Imaging and Remote Sensing Laboratory August 11, Landsat 7 Launched in 1999 Enhanced Terrain Mapper Plus (Vis & IR) 60 m thermal IR resolution “The most stable, best characterized Earth observation instrument ever placed in orbit” a/commons/9/99/Landsat-6.jpg
Digital Imaging and Remote Sensing Laboratory August 11, Thermal Calibration Overview Overpass & ground truth collection Weather data collection Conversion into GIS Image statistics in regions of interest Atmospheric model generation Comparison of model to processed ground truth
Digital Imaging and Remote Sensing Laboratory August 11, Overpass Rochester, NY located in scene overlap (collection every 8 days per satellite) Overpasses occur on subsequent days Same time every time, thanks to orbit Highly weather-dependent (fog, haze, humidity affect results)
Digital Imaging and Remote Sensing Laboratory August 11, Overpass - Locations Ontario Beach Park (confluence of Genesee R. and Lake Ontario)
Digital Imaging and Remote Sensing Laboratory August 11, Overpass - Locations Slater Creek Fishing Access Site, adjacent to RG&E Russell Plant
Digital Imaging and Remote Sensing Laboratory August 11, Overpass - Locations Irondequoit Bay
Digital Imaging and Remote Sensing Laboratory August 11, Overpass - Locations Lake Ontario
Digital Imaging and Remote Sensing Laboratory August 11, Overpass – Ground Truth Thermistor measurements GPS waypoints On-site weather measurements On-site images (sky, waves)
Digital Imaging and Remote Sensing Laboratory August 11, Overpass – More Data Weather buoys (Lake Ontario) Radiosonde (Buffalo, NY)
Digital Imaging and Remote Sensing Laboratory August 11, Preview Image Landsat 7, ETM+ (SLC off)Path 16, Row 307/6/06
Digital Imaging and Remote Sensing Laboratory August 11, Thermal Image Landsat 7Path 17, Row 30 5/18/03
Digital Imaging and Remote Sensing Laboratory August 11, GIS Vector Map Collected data from thermistors, buoys, and balloons is formatted into a GIS-usable vector map with ArcView GIS 3.3
Digital Imaging and Remote Sensing Laboratory August 11, MODTRAN Developed by the USAF Powerful atmospheric modeling tool Allows computation of radiometric values for specific conditions or phenomena Computed from km to 100 km –(lake level to Kármán line… outer space “boundary”)
Digital Imaging and Remote Sensing Laboratory August 11, ENVI Remote sensing & image processing package by ITT VIS (formerly RSI) GIS vector map overlay Region-of-interest (ROI) selection Image statistics calculated
Digital Imaging and Remote Sensing Laboratory August 11, Results
Digital Imaging and Remote Sensing Laboratory August 11, Results
Digital Imaging and Remote Sensing Laboratory August 11, Possible Explanations High humidity skews results MODTRAN quirks Legitimate issue with ETM+ Ongoing calibration happens for this exact reason Not bad for a first try
Digital Imaging and Remote Sensing Laboratory August 11, Special Thanks To… Nina Raqueno Lon Smith Emmett Ientilucci Carl Salvaggio John Schott Victoria Vasso Shara Naas