Water Quality Monitoring & Mapping

Applied Analysis Inc. has developed unique software to determine synoptic water quality parameters using satellite imagery. This software, known as Quantitative Shoreline Characterization (QSC 2), is an adaptation of the IMAGINE Subpixel Classifier and provides the following new functionality:

· Bathymetric Analysis
· Turbidity Analysis
· Quantitative Terrain Categorization

The Bathymetric and Turbidity Analysis capabilities use satellite imagery, primarily Landsat Thematic Mapper, to perform water depth, bottom material, and water quality mapping for a specified area of interest.

The Quantitative Terrain Categorization capability provides information on the material composition of each land pixel within a specified area of interest, i.e., it identifies the principal scene materials and the fraction of each material in each pixel. This is much more powerful than most traditional classifiers.

Photobathymetry using satellite and airborne multispectral sensors is not new, but has only experienced limited success in the past. Several factors can affect performance: not correcting for surface reflections and sun glints, not correcting for bottom material type, not accounting for water column characteristics, inadequate calibration for environmental effects, and lack of compensation for mixed bottom materials, depths, and water column characteristics within individual pixels.

QSC 2 software applies subpixel technology to address all these problems. It includes a unique environmental correction process and explicitly accounts for sun glints at the subpixel level. Mixed depths, bottom materials and water characteristics are addressed through the same technology used by the Subpixel Classifier.

The result is a more accurate estimate of bottom depth and more information about bottom depth, bottom type, and water column characteristics (turbidity, visibility, suspended chlorophyll, suspended sediments, and dissolved organic carbon).

Most terrain categorization algorithms segment the scene into regions and allow you to assign a land cover type to each region. But only QSC can identify mixed land cover types and specify the fraction of each type in a given pixel.

It does this by using the same subpixel technology found in AAI's IMAGINE Subpixel Classifier. The result is a more accurate and more useful terrain categorization.

Includes material © Space Imaging L.P.

The combination of bathymetry analysis and subpixel terrain categorization results in a complete quantitative characterization of the littoral area. AAI is currently offering water quality mapping as an information service. The QSC 2 software is not available for sale.