Description |
This product is a digital elevation model (DEM) for the Little Holland Tract in the Sacramento-San Joaquin River Delta, California based on U.S. Geological Survey (USGS)-collected elevation data, merged with existing topographic and bathymetric elevation data. The USGS collected topographic and bathymetric elevation data in 2015, using a combination of methods. Topographic and shallow-water bathymetric data were collected on foot using a global positioning system (GPS) backpack platform that consisted of survey-grade Trimble R10, and Trimble R7 global navigation satellite system (GNSS) receivers with Zephyr 2 antennas. Bathymetric data were collected using a personal watercraft (PWC) platform that consisted of Trimble R7 GNSS receivers with Zephyr 2 antennas, combined with Odom Echotrac CV-100 single-beam echosounders and 200 kHz transducers. The USGS elevation data were merged with topographic aerial Light Detection and Ranging (lidar) data collected by California Department of Water Resources (DWR) in 2007 and single-beam bathymetric data collected by Environmental Data Solutions (EDS) in 2009 to generate the final DEM. The GeoTIFF raster and comma-delimited text files are available for download at http://doi.org/10.5066/F7RX9954. [More]
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