Remote Sensing: Resources
The capabilities for the remote sensing of water quality at the DNR are tied to the availability of Landsat 7 ETM+ and Landsat 8 OLI-TIRS data through the NASA/USGS Landsat Program. This data is used for the operational satellite retrieval of water clarity from thousands of lakes in Wisconsin and contributes to the assessment of the trophic state of these lakes.
The Landsat Program
The NASA/USGS Landsat Program started when the Earth Resources Technology Satellite 1 (ERTS 1) was launched in 1972. This satellite was later renamed to Landsat 1 and followed by seven more satellites. Landsat 8 is the latest member of the series and was launched in 2013. The Operational Land Imager (OLI) onboard Landsat 8 has nine multispectral bands with a spatial resolution of 30 m and one panchromatic band with a spatial resolution of 15 m. The Thermal Infrared Sensor (TIRS) has two bands with a spatial resolution of 100 m. The multispectral bands are used in the satellite retrieval of water clarity while the panchromatic band might provide important information for the remote sensing of aquatic vegetation. The thermal bands have the potential to advance the remote sensing of water temperature in future remote sensing activities at the DNR.
Satellite data from the Landsat Archive of the USGS EROS Center is downloadable at no cost through the USGS EarthExplorer, Global Visualization Viewer (GloVis) and LandsatLook Viewer.
The LandsatLook Viewer might provide the easiest access to the satellite data.
- Click "Start The LandsatLook Viewer" on the "Welcome to the LandsatLook Viewer!" page and select the satellite(s) you are interested in.
- Click the "Search" icon in the main toolbar to access the search functions.
- Type the name of your county, for example "Vilas County, WI, USA", in the "Find address or place" field and click "Search" to see an overview of your area.
- Select the "Year," "Days of the Year," and "Maximum Cloud Cover" from the dropdown menus and click "Show Images."
- Use the time slider to look through the search results.
- Click "Show Metadata" to download the images.
The NASA Landsat Science and USGS Landsat websites provide excellent resources for detailed information related to the NASA/USGS Landsat Program.
Palmer, S.C.J., Kutser, T., and Hunter, P. (2015) Remote sensing of inland waters: Challenges, progress and future directions. Remote Sensing of Environment, 157, 1-8
Kutser, T., Verpoorter, C., Paavel, B., Tranvik, L.J. (2015) Estimating lake carbon fractions from remote sensing data, Remote Sensing of Environment, 157, 138-146
Brezonik, P.L., Olmanson, L.G., Finlay, J.C., and Bauer, M. (2015) Factors affecting the measurement of CDOM by remote sensing of optically complex inland waters. Remote Sensing of Environment, 157, 199-215
Kutser, T. (2012) The possibility of using the Landsat image archive for monitoring long time trends in coloured dissolved organic matter concentration in lake waters. Remote Sensing of Environment, 123, 334-338