Bathymetric measurements of Little Holland Tract, Sacramento-San Joaquin Delta, California, 2015, from personal watercraft

Bathymetric data were collected by the U.S. Geological Survey (USGS) in 2015 for Little Holland Tract in the Sacramento-San Joaquin River Delta, California. The data were collected using a personal watercraft (PWC) platform that consisted of Trimble R7 Global Navigation Satellite System (GNSS) receivers with Zephyr 2 antennas, combined with Odom Echotrac CV-100 single-beam echosounders and 200 kHz transducers. Data was post-processed to remove spurious data points. Raw depths were converted to ellipsoid elevations in the data acquisition software. Orthometric elevations relative to NAVD88 were computed using National Geodetic Survey Geoid12a offsets, and the final data were projected in Cartesian coordinates using the UTM Zone 10 North (meters) (NAD83[2011]) coordinate system. The mean estimated vertical uncertainty of the 2015 USGS PWC survey is 6.1 cm.