Submit_Time 2007-02-09 16:18:46
Originator Scripps Institution of Oceanography
Title February 2007 Sand Level Measurements in Nearshore Southern California.
Abstract This data set contains 4-column ASCII survey point data from a strip of San Diego County Coastline (including: back beach, beach and swash zone from Torrey Pines State Beach). Terrestrial data was collected using a combination of ATV (Yamaha Grizzly) and pushcart dolly survey systems mounted with in-kind GPS receivers. The survey consisted of 199 variably spaced (25-50 meters in the alongshore) cross-shore transects spanning 8km of beach between the Scripps Pier and Torrey Pines State Beach collected over a multi-day period. Bathymetric data were collected from approximately 2 hours prior to until approximately 2 hours following high tide during multiple consecutive 24-hour spring tide events. Terrestrial data were collected from approximately 2 hours prior to until approximately 2 hours following low tide during multiple consecutive 24-hour spring tide events. One GPS base station (on top of the Center For Coastal Studies Building) was in operation during the survey. The Integrative Oceanography Department, Scripps Institution of Oceanography, UCSD owns and operates the survey systems.
Purpose The data described in this document will be compared with forthcoming data sets to determine rates of shoreline change along the San Diego County Coastline and as a ground truth for simultaneous Lidar surveys as scheduled.
Supplemental_Information The in-house dual transducer sonar system has the following specifications: operating frequency = 192 kHz; sampling frequency = 20 Hz; transmit transducer is 8 degree transmit transducer; receive transducer is 20 degree receive transducer. Bathymetric (WaveRunner) and terrestrial (ATV) systems utilizing Ashtech Global Positioning System (GPS) receivers (Z-Extreme) provide platform positioning. The GPS receivers record pseudo-range and phase information for post-processing. Bathymetric GPS receiver sample rate is 5Hz. Terrestrial GPS receiver sample rates are 1 Hz. Platform (WaveRunner and ATV) orientation is determined with a GyroTrac Gyro recording roll, pitch and yaw at 10 Hz. In addition to post-processed data 1 Hz real-time kinematic carrier phase differentially corrected data are also acquired as a navigation aid and as a supplement to post-processed data.
Currentness_Reference ground condition
Maintenance_and_Update_Frequency As needed
Temporal_Keyword 2007, February
Logical_Consistency_Report Not Applicable
Completeness_Report This survey was completed in a single evening. Driver (POS Region): kent Driver (NCEX Region): ian POS region spans T84-T111, NCEX region spans T34-T57 Low tide was at 3:44pm -1.1 The rivermouth was flowing and not passable Bathtub rock was passable. SIO Base Station: Lat: 32 deg 51 min 58.95411 sec Lon: -117 deg 15 min 14.23074 sec Height: -21.753 meters GPS sampling was 5Hz for the ATV and 5Hz for the Base. ATV antenna height 1.846M. dollygeoidposncex.m was used to filter the data because the brick was not working correctly.
Process_Description Transfer raw GPS data from base station and rover Ashtech GPS receivers for each of the surveys conducted to processing computer.
Geographic_Coordinate_Units Decimal degrees
Horizontal_Datum_Name North American Datum of 1983
Ellipsoid_Name Geodetic Reference System 80
Altitude_Datum_Name North American Vertical Datum of 1988
Altitude_Encoding_Method Explicit elevation coordinate included with horizontal coordinates
Contact_Organization Scripps Institution of Oceanography
Contact_Person Robert Guza
Contact_Position Co-Principle Investigator
Address 9500 Gilman Drive
City La Jolla
Country United States
Metadata_Standard_Name FGDC Content Standards for Digital Geospatial Metadata