September 2008 Scripps Institute of Oceanography (SIO) Lidar of the Southern California Coastline: Long Beach to US/Mexico Border
This kmz file shows the extent of coverage for the September 2008 SIO Southern California Coastline lidar data set.
This lidar point data set was collected during low tide conditions along an approximately 500-700 meter wide strip of the Southern California coastline within an area extending south from Long Beach to the US/Mexico border. Data were collected in Los Angeles, Orange and San Diego counties from south of the Downtown Long Beach Marina in Long Beach, California to Leucadia, California on September 30, 2008 between 20:46 and 23:25 UTC. Data were collected in Orange and San Diego counties from Dana Point, California to south of the United States-Mexico border near Playas de Tijuana, Baja California, Mexico on September 29, 2008 between 20:08 and 23:08 UTC. Data set features include water, beach, cliffs, and top of cliffs. The all points data set contains the complete point cloud of first and last return elevation and laser intensity measurements recorded during the fall 2008 airborne lidar survey conducted semi-annually by the University of Texas at Austin for the Southern California Beach Processes Study. The data set was generated by the processing of laser range, scan angle, and aircraft attitude data collected using an Optech Inc. Airborne Laser Terrain Mapper (ALTM) 1225 system and geodetic quality Global Positioning System (GPS) airborne and ground-based receivers. Instrument settings and parameters during survey were: Nominal on-ground beam diameter: 25 cm Pulse rate: 25 kHz Maximum number of returns recorded: 2 Minimum separation between detected returns from a single pulse: 4.3 m Laser wavelength: 1064 nm Frequency of GPS sampling: 1 Hz Frequency of IMU sampling: 50 Hz; Scan angle: +/- 20 degrees Nominal height of instrument above ground: 1100 m Nominal single-swath pulse density: 2 m Nominal aggregate pulse density: 0.75 Nature of vertical control: Kinematic and static GPS points
|Other Access||Online access information not available.|
|Distributor||DOC/NOAA/NOS/OCM > Office for Coastal Management, National Ocean Service, National
Oceanic and Atmospheric Administration, U.S. Department of Commerce
|Dataset Point of Contact||Roberto Gutierrez
Research Associate in Geodesy and Geophysics
University of Texas at Austin Center for Space Research
Documentation links not available.
|Data Presentation Form:|| Digital image
|Dataset Progress Status||Complete|
|Data Update Frequency:||As needed|
The University of Texas at Austin Center for Space Research operated an Optech Inc. Airborne Laser Terrain Mapper (ALTM) 1225 system installed in a single engine Cessna 206 to collect lidar data for the survey. Global Positioning System (GPS) data were collected simultaneously with three geodetic quality Ashtech Z-12 receivers installed in the aircraft and at two temporary base stations operated during the survey. An Inertial Measurement Unit (IMU) used three orthogonal accelerometers and gyroscopes to collect in-flight instrument orientation information. The Cessna 206 aircraft used in the survey is owned and operated by the Texas Department of Transportation. The ALTM 1225 (SN#99d118) lidar instrument has the following specifications: operating altitude = 410-2,000 m AGL; maximum laser pulse rate = 25 kHz; laser scan angle = variable from 0 to +/-20deg from nadir; scanning frequency = variable, 28 Hz at the 20deg scan angle; and beam divergence: narrow = 0.2 milliradian (half angle, 1/e). The ALTM 1225 records the range and backscatter intensity of the first and last laser reflection using an Avalanche Photo diode constant-fraction discriminator and two Timing Interval Meters (TIM). ALTM elevation points are computed using three sets of data: laser ranges and their associated scan angles, platform position and orientation information, and calibration data and mounting parameters (Wehr and Lohr, 1999). Global Positioning System (GPS) receivers in the aircraft and on the ground provide platform positioning. The GPS receivers record pseudo-range and phase information for post-processing. Platform orientation information comes from an Inertial Measurement Unit (IMU) containing three orthogonal accelerometers and gyroscopes. An aided-Inertial Navigation System (INS) solution for the aircraft's attitude is estimated from the IMU output and the GPS information.
|Purpose:||The data described in this document will be compared with previous and forthcoming data sets to determine rates of shoreline change along the Southern California coastline. The SCBPS program is designed to improve the understanding of beach sand transport by waves and currents, thus improving local and regional coastal management.|
|Time Period:||2008-09-29 to 2008-09-30|
|Spatial Reference System:||urn:ogc:def:crs:EPSG::4269|
|Spatial Bounding Box Coordinates:||
|Spatial Coverage Map:|
|Use Constraints||No constraint information available|
|Fees||Fee information not available.|
Last Modified: 2013-06-05
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