January 16 2009

     CSCAP, a special project within the Remote Sensing Division of NGS, is being developed to enable RSD personnel to analyze shoreline changes by comparing recent high resolution satellite imagery or high altitude reconnaissance aerial photography with existing NOAA raster and vector nautical charts. By digitally overlaying the satellite imagery with the charts, changes in shoreline features (piers, bulkheads, shoreline configuration, jetties, groins, etc.) can be easily detected. Shoreline changes are noted and used to aid in updating nautical charts. Alternatively , the information is used internally by RSD to help determine which shoreline areas require revision using aerial photography and standard photogrammetric techniques. This allows the Remote Sensing Division to focus its shoreline compilation efforts where they are most needed. 

 
 
 
 
 
 
 
 
 
 

  
The process of shoreline change analysis using CSCAP currently consists of six steps:

  1.  Acquire high resolution satellite imagery (primarily IKONOS and Quickbird)

  2.  Acquire and georeference accurate shoreline base maps (NOS t-sheets or digital manuscripts)

  3.  Fine-tune the georeferencing of the satellite imagery by choosing common points on the imagery and on the base maps and resampling the imagery to fit the geometry of the base map.

  4.  Bring all data (imagery and nautical charts) to a common projection, spheroid and datum, and display as layers in a GIS.

  5.  Analyze changes and record in a point file with descriptions of  the changes noted.

6.  Pass this information on to either Office of Coast Survey or NGS Remote Sensing Division personnel depending on the purpose of the project.
 

 
At the present time CSCAP reconnaissance projects are selected from the 56 largest US ports as measured by shipping tonnage. Current sources of high resolution (1-5m) satellite imagery used in CSCAP are:

 
SENSOR
SPATIAL RESOLUTION
SOURCE
LINK
QUICKBIRD 0.6 meter Digital Globe www.digitalglobe.com
IKONOS 1 meter Space Imaging www.spaceimaging.com

 
RSD personnel will continue to evaluate new sources of imagery as they become available and incorporate them into CSCAP.  Future development efforts will be directed toward determining the accuracy of shoreline data compiled from satellite imagery.

 
For more information on CSCAP contact Susan Vidal