Submit_Time 2015-01-14 22:09:25
Originator Scripps Institution of Oceanography
Title December 2014 Sand Level Measurements in Nearshore Southern California.
Abstract This data set contains 5-column ASCII survey point data from a strip of San Diego County Coastline extending from the Tijuana River mouth northward approximately 3.8km to the second breakwater north of the Imperial Beach pier. Low tide data was collected with the ATV sampled at 5 Hz.
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 Terrestrial (ATV) systems utilizing Ashtech Global Positioning System (GPS) receivers (Z-Extreme) provide platform positioning. The GPS receivers record pseudo-range and phase information at 5Hz for post-processing. 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. The data files are comprised of five columns: Lat, Lon, Z(rel. to MSL), DateTime(UTC), Substrate type. The Substrate type is defined by a numeric code: 0 = No data, 1 = Sand, 2 = Cobbles, 3 = Bedrock. The substrate type was identified by the ATV driver at the time of the survey.
Currentness_Reference ground condition
Maintenance_and_Update_Frequency During Low-Low Tide episodes.
Place_Keyword IMPERIAL BEACH
Temporal_Keyword 20141205, December 2014
Logical_Consistency_Report Not Applicable
Completeness_Report ; DATE: Dec. 8/14 (date/time of processing) ; TIME: 8:42:18 ; CREATED BY: GrafNav Version 8.10.2428 MB_MASTER_FILE = C:surveydataatv20141205BBASEA14.gpb MB_MASTER_POS = 32 34 43.64475 -117 07 57.18054 -28.3240 MB_MASTER_ANT = 0.056 0.006 0.000 0 ASH701975.01A 0 REMOTE_FILE = C:surveydataatv20141205BROVRA14.gpb REMOTE_POS = 32 34 43.56349 -117 07 57.17191 -16.2286 REMOTE_ANT = 0.056 0.006 0.000 0 ASH701975.01A 0 DATUM = NAD83_CORS96 AUTO ; Processing Datum ELEV_MASK = 10.0 ; Elevation mask (deg) GRID = UTM 1 0 ; Grid info Location = Imperial Beach Post Processed GPS File = C:surveydataatv2014120520141205.txt Kinematic GPS File = C:surveydataatv20141205G20141205.dat Gyro File = C:surveydataatv20141205A20141205.dat Substrate File = C:surveydataatv20141205S20141205.dat Antenna Height = 1.720000 flag_ppv = 1.000000 UTC vs GPS time offset (seconds) = -16.000000 Mean Offsets from Control Point: X = -3.2cm, Y= 15.3cm, Z = -1.7cm Time of first Sample at Control Point (UTC Hours): 19.261111 Time of last Sample at Control Point (UTC Hours): 23.661104 Number of Samples at Control Point: 3829 Imperial Beach (south section), Transects 1-42 \BeachIB09OLD_organizationIBpier_bathyatv20141205-alongshore This survey was done in a single afternoon. Wave conditions were small. Drivers: Upper beach - Rob Lower beach - Brian Tide: -0.9 ft low at 2:40pm NOTES: Green ATV was used for this survey. Data were processed by Brian without gyro using atvgeoidall_nogyro.m. There were some substrate switch and RTK issues, but both were resolved. QCd by Rob. Tablet used was Toughpad #1.
Process_Description Transfer raw GPS data from both base station and rover Ashtech GPS receivers to processing computer. Waypoint Consulting's Grafnav program processes the dual frequency GPS data for a NAD83 solution. Matlab programs then adjust the position and elevation by using the gyro data.
Geographic_Coordinate_Units Decimal degrees
Horizontal_Datum_Name North American Datum of 1983 (CORS96)
Altitude_Datum_Name North American Vertical Datum of 1988
Altitude_Encoding_Method Explicit elevation coordinate included with horizontal coordinates
Entity_and_Attribute_Detail_Citation Scripps Institution of Oceanography, 2014
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