Submit_Time 2009-09-04 08:51:55
Originator Scripps Institution of Oceanography
Title August 2009 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 US-Mexico Border northward approximately 2.5km to the Tijuana River mouth. 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.
Temporal_Keyword 2009, August
Logical_Consistency_Report Not Applicable
Completeness_Report ; DATE: Aug. 31/09 (date/time of processing) ; TIME: 13:47:22 ; CREATED BY: GrafNav Version 8.10.2428 MB_MASTER_FILE = C:surveydataatv20090821BBASEA09.gpb MB_MASTER_POS = 32 32 10.92787 -117 07 22.39667 -31.1920 MB_MASTER_ANT = 0.056 0.006 0.000 0 ASH701975.01A 0 REMOTE_FILE = C:surveydataatv20090821B____A09.gpb REMOTE_POS = 32 32 12.16968 -117 07 23.28217 33.3686 REMOTE_ANT = 0.056 0.006 0.000 0 ASH701975.01A 0 DATUM = ITRF00 AUTO ; Processing Datum ELEV_MASK = 10.0 ; Elevation mask (deg) GRID = UTM 1 0 ; Grid info Location = TJ Rivermouth Post Processed GPS File = C:surveydataatv2009082120090821.233 Kinematic GPS File = C:surveydataatv20090821G20090821.dat Gyro File = C:surveydataatv20090821A20090821.dat Substrate File = C:surveydataatv20090821S20090821.dat Antenna Height = 1.784000 flag_ppv = 2.000000 UTC vs GPS time offset (seconds) = -15.000000 Mean Offsets from Control Point: X = -1.5cm, Y= -4.6cm, Z = 0.2cm Time of first Sample at Control Point (UTC Hours): 21.947020 Time of last Sample at Control Point (UTC Hours): 23.664708 Number of Samples at Control Point: 6468 medium 2-3foot surf. Survey was completed in a single morning. Drivers: Andrew, Rob Tide: 0.8 @ 14:25PST GPS sampling was 5 Hz for both ATV and Base.
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 an IRTF00 solution. Matlab programs then adjust the position and elevation by using the gyro data.
Process_Date August 31, 2009
Geographic_Coordinate_Units Decimal degrees
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, 2009
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