Skip to main content

Alexander G. Snyder

thumbnail
This portion of the USGS data release presents bathymetry data collected during surveys performed in northern Monterey Bay, California in March 2016 (USGS Field Activity Number 2016-627-FA). Bathymetry data were collected using two personal watercraft (PWCs) equipped with single-beam sonar systems and global navigation satellite system (GNSS) receivers. The sonar systems consisted of an Odom Echotrac CV-100 single-beam echosounder and 200 kHz transducer with a 9° beam angle. Raw acoustic backscatter returns were digitized by the echosounder with a vertical resolution of 1.25 cm. Depths from the echosounders were computed using sound velocity profiles measured using a YSI CastAway CTD during the survey. Positioning...
thumbnail
This portion of the USGS data release presents topography data collected during surveys performed along northern Monterey Bay, California, in March 2015 (USGS Field Activity Number 2015-625-FA). Topographic profiles were collected on foot with GNSS receivers mounted on backpacks. Prior to data collection, vertical distances between the GNSS antennas and the ground were measured using a tape measure. Hand-held data collectors were used to log raw data and display navigational information allowing surveyors to navigate survey lines spaced at 50- to 250-m intervals along the beach. Profiles were surveyed from the landward edge of the study area (either the base of a bluff, engineering structure, or just landward of...
thumbnail
This portion of the USGS data release presents bathymetry data collected during surveys performed in northern Monterey Bay, California in March 2015 (USGS Field Activity Number 2015-625-FA). Bathymetry data were collected using two personal watercraft (PWCs) equipped with single-beam sonar systems and global navigation satellite system (GNSS) receivers. The sonar systems consisted of an Odom Echotrac CV-100 single-beam echosounder and 200 kHz transducer with a 9° beam angle. Raw acoustic backscatter returns were digitized by the echosounder with a vertical resolution of 1.25 cm. Depths from the echosounders were computed using sound velocity profiles measured using a YSI CastAway CTD during the survey. Positioning...
thumbnail
This portion of the USGS data release presents digital elevation models (DEMs) derived from bathymetric and topographic surveys conducted along northern Monterey Bay, California, in September 2017 (USGS Field Activity Number 2017-678-FA). Nearshore bathymetry data were collected using two personal watercraft (PWCs) equipped with single-beam echosounders and survey-grade global navigation satellite system (GNSS) receivers. Topography data were collected using an all-terrain vehicle equipped with a GNSS receiver and on foot with GNSS receivers mounted on backpacks. Additional topography data were collected with a terrestrial lidar scanner. Positions of the survey platforms were referenced to a GNSS base station placed...
thumbnail
This part of the data release presents topography data from northern Monterey Bay, California collected in March 2016 using a tripod-mounted Riegl VZ-1000 lidar scanner (USGS Field Activity 2016-627-FA). For each area surveyed, the scanner was placed at several positions which were selected to provide maximum line-of-sight coverage of the area of interest. Scans were typically conducted in panoramic mode, creating a detailed point cloud of all unobstructed surfaces in a 360 degree view of the scanner. At each scan position, co-registered photographic imagery was also collected with a scanner mounted DSLR camera. Scanner registration was performed by placing four or more cylindrical or flat reflective tripod-mounted...
View more...
ScienceBase brings together the best information it can find about USGS researchers and offices to show connections to publications, projects, and data. We are still working to improve this process and information is by no means complete. If you don't see everything you know is associated with you, a colleague, or your office, please be patient while we work to connect the dots. Feel free to contact sciencebase@usgs.gov.