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The Coast and Shoreline Change Analysis Program (CSCAP) Maryellen Sault NOAA’s National Geodetic Survey Remote Sensing Division • NOAA – National Ocean Service • National Geodetic Survey – Remote Sensing Division • Primary programs – Coastal Mapping Program – Aeronautical Survey Program Our Focus Coastal Mapping Program • NOAA's National Geodetic Survey (NGS) has the mandate to survey coastal regions within the U.S. and territories. • NGS delineates the shoreline through stereo photogrammetry, using tide-coordinated aerial photography controlled by kinematic Global Positioning System (GPS) techniques. • CSCAP utilizes high resolution satellite imagery and NOAA’s Electronic Navigational Charts (ENC) to look for shoreline change within major port cities. • The Coast and Shoreline Change Analysis Program (CSCAP) is a sub-component within the CMP and is the first step in the Electronic Navigational Chart Validation Initiative. Digital Digital Photogrammetric Photogrammetric Workstation Workstation used for used for aerotriangulation aerotriangulation and feature and feature extraction extraction ENC VI: A Multi-Organizational Process CSCAP Evaluated Imagery • SPOT – 10 m spatial resolution • IRS – 5 m spatial resolution • SPIN2 – 2 m spatial resolution • IKONOS – 1 m spatial resolution • Quickbird – 0.60 m spatial resolution Charleston, SC IRS Image Image Source: Space Imaging 5 meter spatial resolution Charleston, SC SPIN2 Image Image Source:Aerial Images 2 meter spatial resolution Portland, OR IKONOS Image Image Source: Space Imaging 1 meter spatial resolution Ponce, PR Quickbird Image Image Source: Digital Globe 60 centimeter spatial resolution Future Satellites GeoEye-1 (GeoEye) • Anticipated launch in early 2007 • 0.41 m panchromatic spatial resolution • 1.64 m multispectral spatial resolution • 1.2 million sq. KM of imagery/day • 1.5 day revisit period WorldView 1(Digital Globe) • Anticipated launch in mid-2007 • 0.50 m panchromatic spatial resolution • 500,000 sq. km of imagery/day • 1.7 day average revisit time. CSCAP Processing Steps • Improve relative positioning • Change Analysis • NOAA Electronic Navigational Chart and NOAA Raster Nautical Chart compared with High Resolution Satellite Imagery. • Georeference Imagery using ground control • Accuracy Assessment • Shoreline Compilation • Field Verification Relative vs Absolute Georeferencing Relative • Uses image coordinates to align shoreline with image. • User defined links between features on image and shoreline • Utilizes a first order polynomial transformation • NO ACCURACY INFORMATION Absolute • Utilizes best available control • Register imagery to reference data • Uses a first- order polynomial transformation • IMAGE ACCURACY IS KNOWN Image Source: Digital Globe Image Source: Digital Globe Image Source: Digital Globe Chart Evaluation File (CEF) Image Source: Digital Globe Charlotte Amalie 2003 Quickbird Image Christiansted 2003 Quickbird Image Christiansted 2003 Quickbird Image Absolute Georeferencing • Obtain ~ 30 GPS ground control points 10 – Re-georeferencing 20 – Accuracy Assessment • Provide approximate locations for field crew • Use a first-order polynomial Accuracy Assessment Procedures • Procedures are based on the Geospatial Positioning Accuracy Standards Part 3: National Standard for Spatial Data Accuracy document provided by the Federal Geographic Data Committee (FGDC) • Root mean square error is used to estimate positional accuracy. • An independent source of higher accuracy control must be used. • A minimum of 20 check points shall be used. • Check points must be distributed to reflect the geographic area of interest. Image Georeferencing Accuracy Location Image georeferencing source RMSx RMSy RMSr CE at 95% confidence level Alameda GPS Data Points 0.57 m 0.55 m 0.79 m 1.36 m Carquinez GPS Data Points 0.49 m 0.47 m 0.68 m 1.17 m Image Source: Space Imaging, LLC Image Source: Space Imaging, LLC Field Verification Limitations • Ground control and check points must be collected for areas to be compiled • Factors that limit accuracy of compiled shoreline: – Spatial resolution – Georeferencing accuracy – Possibility of unknown, nonsystematic geometric problems with the imagery – Cannot be tide coordinated – Attribution is difficult and varies depending on atmospheric conditions Data Distribution Data Distribution Data Distribution Metadata Shoreline Applications NOAA’s Shoreline may be used for: • Application to Navigational Charts • Historical Shoreline Change Analysis • Land and marine geographic information systems (GIS) basemaps • Property management, real estate • Coastal disputes • Natural resource management • Coastal zone management • Maritime boundaries Shoreline Application to Nautical Charts Image Source: Space Imaging, LLC Historical Shoreline Change 2004 Aerial photograph Fort Desoto Beach, FL 1976 1957 Summary • High resolution satellite imagery can be a useful tool for shoreline feature change analysis in ports. • Accurate georeferencing is crucial. • The Chart Evaluation File (CEF) follows the project through the entire multi-organizational process of the ENC Validation Initiative • Shoreline is delivered in a GIS friendly format and can be downloaded from http://www.ngs.noaa.gov/RSD/shoredata/NGS_Shoreline_Products.htm