U.S. Geological Survey Data Series 514
Swath Bathymetry Surveys of the Monterey Bay Area from Point Año Nuevo to Moss Landing, San Mateo, Santa Cruz, and Monterey Counties, California
A Note on Coordinate Systems
WGS84 and NAD83 have been revised several times resulting in coordinate shifts of up to several meters in X,Y, and Z. The revision is indicated by the designator following the name (G1150 following WGS84, for example). Be very careful using software that does not distinguish between the different versions of these datum; lack of the designator is a warning sign that your software does not support 3D datum properly. Users should pay particular attention to the accompanying metadata files to ensure that the data are properly georeferenced. In particular, note that most current GIS software (including ArcGIS 9.3) cannot properly transform high-resolution elevation data from one 3D datum to another (such as WGS84 G1150 to NAD83 CORS96) without introducing errors on the order of 1 m to 2 m in X,Y, and Z. For this reason, data are provided in both WGS84 G1150 (equivalent to ITRF2000) and NAD83 CORS96 (Equivalent to NSRS2007).
The raw bathymetry dataset is provided in ESRI GRID and ASCII GRID format in WGS84 (G1150), UTM Zone 10 North.
The standard deviation of the raw bathymetry grid is provided in ESRI ASCII GRID format in WGS84 (G1150), UTM Zone 10 North. This represents the weighted standard deviation for all of the soundings used to compute the elevation of the grid cell.
The interpolated bathymetry DEM is provided in ESRI ASCII GRID format in WGS84 (G1150) and NAD83(CORS96), UTM Zone 10 North (vertical datum NAVD88). A full resolution hillshaded image of the data can be viewed with any KML viewer through the following KML link. (.kmz)
The amplitude dataset is provided as a geotiff with a worldfile and in ESRI ASCII GRID format in WGS84 (G1150) and NAD83(CORS96), UTM Zone 10 North. Users should consider the file size when choosing which product to download. Full-resolution backscatter imagery can also be viewed online with any KML viewer through the following link. (.kmz)
Sound velocity profiles are provided in a .kmz file viewable in Marble, Google Earth, Microsoft Virtual Earth, Nasa Worldwind, and other viewers which support the .kml standard. Text files and plot images also are provided in a zipped archive below. These data are ancillary to SWATH mapping and are provided primarily for completeness and archival purposes. A total of 438 sound velocity profiles were taken during this project. Coordinates are provided in WGS84 (G1150), UTM Zone 10 North, and in geographic coordinates. (.kmz)
For more information, contact David Finlayson.