50015
September 2008 Scripps Institute of Oceanography (SIO) Lidar of the Southern California Coastline: Long Beach to US/Mexico Border
scripps_200809_m571_metadata
Data Set
Published / External
49401
Lidar - partner (no harvest)
Project
Completed
2011-03
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
Original contact information:
Contact Name: Roberto Gutierrez
Contact Org: University of Texas at Austin Center for Space Research
Title: Research Associate in Geodesy and Geophysics
Phone: 512.471.5573
Email: oskar@mail.utexas.edu
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.
10659
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.
A footprint of this data set may be viewed in Google Earth at:
https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/571/supplemental/Scripps_September_2008_Lidar_Long_Beach_to_Mexico_Border.kmz
Theme
ISO 19115 Topic Category
elevation
Theme
Beaches
Theme
Coastal Landforms/Processes
Theme
GPS
Theme
GPS Receivers
Theme
Landforms
Theme
Shorelines
Temporal
2008
Temporal
September
Temporal
low tide
Office for Coastal Management
Charleston
SC
Data Set
As Needed
Any conclusions drawn from analysis of this information are not the responsibility of the Scripps Institution of Oceanography, the UT Center for
Space Research, the Bureau of Economic Geology, The University of Texas at Austin or the NOAA Office for Coastal Management or its partners.
This dataset was generated for the Scripps Institution of Oceanography by the Center for Space Research, the University of Texas at Austin (CSR),
with support provided by the Bureau of Economic Geology, the University of Texas at Austin (BEG), and the Government Flight Services of the
Texas Department of Transportation. Acknowledgement of the data originators is requested when using the data set as a source.
Data Steward
2011-03
Organization
NOAA Office for Coastal Management
NOAA/OCM
coastal.info@noaa.gov
2234 South Hobson Ave
Charleston
SC
29405-2413
(843) 740-1202
https://coast.noaa.gov
NOAA Office for Coastal Management Home Page
Online Resource
Distributor
2011-03
Organization
NOAA Office for Coastal Management
NOAA/OCM
coastal.info@noaa.gov
2234 South Hobson Ave
Charleston
SC
29405-2413
(843) 740-1202
https://coast.noaa.gov
NOAA Office for Coastal Management Home Page
Online Resource
Metadata Contact
2011-03
Organization
NOAA Office for Coastal Management
NOAA/OCM
coastal.info@noaa.gov
2234 South Hobson Ave
Charleston
SC
29405-2413
(843) 740-1202
https://coast.noaa.gov
NOAA Office for Coastal Management Home Page
Online Resource
Point of Contact
2011-03
Organization
NOAA Office for Coastal Management
NOAA/OCM
coastal.info@noaa.gov
2234 South Hobson Ave
Charleston
SC
29405-2413
(843) 740-1202
https://coast.noaa.gov
NOAA Office for Coastal Management Home Page
Online Resource
Ground Condition
-118.00025
-117.117638
33.662182
32.509061
Range
2008-09-29
2008-09-30
Yes
Unclassified
This data can be obtained on-line at the following URL: https://coast.noaa.gov/dataviewer
;
None
These data were collected to support the Southern California Beach Processes Study. Any conclusions drawn from analysis of this information are
not the responsibility of the Scripps Institution of Oceanography, the UT Center for Space Research, the Bureau of Economic Geology, or the
University of Texas at Austin. Interested parties are advised to review metadata contents prior to use. These data are best used at scales
appropriate for raster or gridded data collected at a nominal resolution of 1-2 meters (approximately 1:12000). Users should be aware
that temporal changes may have occurred since this data set was collected and some parts of this data may no longer represent actual surface
conditions. Users should not base critical applications on this data set without full awareness of potential limitations.
https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=571
Customized Download
Create custom data files by choosing data area, product type, map projection, file format, datum, etc.
https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/571/index.html
Bulk Download
Simple download of data files.
https://coast.noaa.gov
Online Resource
https://coast.noaa.gov/dataviewer
Online Resource
2016-05-23
Date that the source FGDC record was last modified.
2017-11-14
Converted from FGDC Content Standards for Digital Geospatial Metadata (version FGDC-STD-001-1998) using 'fgdc_to_inport_xml.pl' script. Contact Tyler Christensen (NOS) for details.
2018-02-08
Partial upload of Positional Accuracy fields only.
2018-03-13
Partial upload to move data access links to Distribution Info.
Maximum allowable PDOP using a 15 degree elevation mask during data collection was 3.5. The lidar data is estimated to have a horizontal
error of less than or equal to 1.0 m. To assess horizontal accuracy, selected portions from each lidar data set (last return only) were
used to generate a 1m x 1m digital elevation model (DEM). Data from ground surveys conducted using kinematic GPS techniques and estimated
to have a horizontal accuracy of 0.01-0.03 m were superimposed on the lidar DEM and examined for any mismatch between the horizontal
position of the ground GPS and the corresponding feature on the lidar DEM. Horizontal agreement between the ground kinematic GPS and the
lidar was within the resolution of the 1m x 1m DEM.
(North) The September 30, 2008, lidar data were compared to kinematic GPS ground survey points collected along an approximately 2 kilometer
long stretch of the East Pacific Coast Highway near Laguna Beach. The September 30, 2008, lidar data set was sorted to find data points
that fell within 1 m of the GPS points.
(South) The September 29, 2008, lidar data were compared to 17 GPS ground survey points collected throughout a parking lot adjacent to the
North Torrey Pines Road. The September 29, 2008, lidar data set was sorted to find data points that fell within 2 m of the GPS points.
For each survey area (north and south), the mean elevation difference between the selected lidar points and their respective GPS points
was used to estimate and remove elevation bias from the lidar. The standard deviation of the elevation differences provided estimates
of the lidar precision. The bias was removed so that mean lidar elevations have a vertical accuracy of 0.10 m RMSE.
This data set contains data within a narrow strip (~700 m) of the Southern California coastline. A decimated dataset was visually inspected for
completeness. Some beach edges may be missing. Data collected west of the northwestern corner of the Downtown Long Beach Marina
(Longitude 118d11m0.63s W) and south of the US-Mexico border at Playas de Tijuana (Latitude 32d32m1.80s N) may be of poor quality and should
not be used for analysis. Data collected during the third pass of September 29 (pass 27308C) were noisier than desirable. Unacceptable data
points were removed from that pass.
Data points lacking either first or last return values were removed from the data set. An automated method was used to remove obvious outliers.
Only data points with vertical values greater than or equal to -20 m and less than or equal to 250 m were retained in the all points data set.
ALTM 1225 range files
Range
2008-09-29
2008-09-30
Range files are the source data collected by the ALTM 1225 sensor.
ALTM 1225 range files used for this survey are grouped by date, day of year, pass, pass location, and time of collection (all times UTC):
Fall 2008
September 29, 2008 (Day of Year = 273), HH:MM in UTC
===================================================
27308 Pass A (San Onofre to La Jolla) 20:07-20:28
27308 Pass B (La Jolla to Dana Point) 20:31-21:01
27308 Pass C (La Jolla to Point Loma) 21:31-21:40
27308 Pass D (Coronado (North Island NAS) to Playas de Tijuana) 21:45-21:52
27308 Pass E (Playas de Tijuana to Coronado (North Island NAS)) 21:55-22:04
27308 Pass F (Coronado (North Island NAS) to Playas de Tijuana) 22:09-22:16
27308 Pass G (Point Loma to Santa Margarita River) 22:23-23:08
September 30, 2008 (Day of Year = 274), HH:MM in UTC
===================================================
27408 Pass A (Leucadia to Long Beach) 20:46-21:25
27408 Pass B (Long Beach to Dana Point) 21:29-21:48
27408 Pass C (Dana Point to Long Beach) 21:52-22:10
27408 Pass D (Long Beach to Carlsbad) 22:16-23:02
27408 Pass E (Leucadia to Dana Point) 23:06-23:24
| Source Geospatial Form: tabular digital data | Type of Source Media: digital files
Air and Ground GPS L1, L2, pseudorange and phase files from September 29 & 30, 2008 (Days of Year 273 & 274)
Range
2008-09-29
2008-09-30
Two Ashtech Z-12 GPS receivers placed at precisely located base stations collected GPS data at 1 second intervals throughout the period
of airborne lidar data collection. Data collection commenced prior to take off and ceased subsequent to touch down. A third Ashtech
Z-12 GPS receiver collected in-flight GPS data at 1 second intervals. Data were downloaded and stored each day after flight completion.
File names included standardized references to location and date. These data were used for ALTM range file processing. See process steps
for more detailed information.
GPS base station locations by survey day:
September 30 (day 274), 2008: SANO, SEAL
September 29 (day 274), 2008: SANO, LOMA
GPS base station attributes:
ID: SANO
Name: HPGN-CA SDGPS01, 1990; Description: San Diego County Engineer Department GPS control point at San Onofre
NAD83 Coordinates and HAE: 33d 22m 31.08420s N, 117d 33m 54.54673s W, -5.17
ID: SEAL
Name: HPGN CA 12 01; Description: California High Precision GPS Network 12 01 (PID:DY9309)
NAD83 Coordinates and HAE: 33d 44m 15.03481s N, 118d 05m 17.76708s W, -27.228
ID: LOMA
Name: LOMA EAST; Description: NGS Control Point at Loma Point, LOMA EAST, 1994 (PID: AC6092)
NAD83 Coordinates and HAE: 32d 40m 13.99579s N, 117d 14m 27.74509s W, 90.892
| Type of Source Media: digital files
GPS Continuously Operating Reference Station (CORS) at Pinyon Flats, CA
Range
2008-09-29
2008-09-30
GPS base stations solutions were estimated with respect to the GPS Continuously Operating Reference Station (CORS) at Pinyon Flats, CA.
DESIGNATION: PINON 1 PGGA CORS ARP
CORS_ID: PIN1
NGS PID: AF9708
| Type of Source Media: online
1
ALTM range files were downloaded from the Optech ALTM 1225 system and decoded using Optech's REALM 3.0 tape decode program.
2
Raw GPS data were downloaded from three Ashtech Z-12 GPS receivers. One receiver collected in-flight aircraft data; the other two
collected data during flight time at separate base stations. The GPS data were converted into RINEX2 format with pseudorange smoothing
applied. The National Geodetic Survey's PAGES-NT software was used to compute double differenced, ionospherically corrected, static
GPS solutions for each GPS base station with precise ephemerides from the International GPS Service (IGS) with respect to selected CORS
sites. As part of the solution tropospheric zenith delays were estimated and L1 and L2 phase biases were fixed as integers. Aircraft
trajectories were estimated with respect to all base stations using National Geodetic Survey's Kinematic and Rapid-Static Software (KARS)
software. Trajectories were double-differenced, ionospherically corrected, bias-fixed GPS solutions computed with precise IGS ephemerides.
Coordinates for base stations and trajectories were in the International Terrestrial Reference Frame of 2000 (ITRF00). Aircraft
trajectories were transformed from the ITRF00 to North American Datum of 1983 (NAD83) using the Horizontal Time Dependent Positioning (HDTP)
software (Snay, 1999).
3
The 1 Hz GPS trajectory and 50Hz aircraft inertial measurement unit (IMU) data were combined in Applanix's POSProc version 4.2 to compute
an aided inertial navigation solution (INS) and a 50 Hz, smoothed best estimate of trajectory (SBET). The POSPac software employs a Kalman
filter to obtain a blended navigation solution. Afterwards, smoothing was applied to the solution to obtain the SBET for the aircraft.
4
The SBET, laser range observations, scanner position information, and GPS/internal clock files were processed in the Realm 2.27 software
suite to generate uncalibrated lidar data points in the Universal Transverse Mercator (UTM) projection. Lidar point data were compared
to 1998 ATM LIDAR data over several cross-track piers and roads to estimate lidar instrument calibration parameters: roll and pitch biases,
scanner scale factor, and first/last return elevation biases. An iterative, least-squares methodology was used to estimate calibration
parameters so as to minimize differences between lidar and ground GPS data.
Samples of lidar data were used to create high-resolution digital elevation models (DEM); these DEMs were inspected for horizontal or
vertical anomalies. Data collected on September 30, 2008, were compared to kinematic GPS points collected along the E. Pacific Coast Hwy
near Laguna Beach. Data collected on September 29, 2008, were compared to kinematic GPS points collected in a parking lot near North
Torrey Pines Road. After system calibration and initial quality control step, the adjusted lidar x,y,z-point data were generated by
REALM software and output using the UTM Zone 11 coordinate system with elevations being heights above the GRS-80 reference ellipsoid (HAE).
The output format from REALM 2.27 is a headerless space-delimited 9-column ASCII file that contains:
Column 1 = the point time tag in seconds in the GPS week;
Columns 2-4 = the UTM Zone 11 North easting, UTM Zone 11 North northing and height above ellipsoid (HAE) of the first lidar return;
Columns 5-7 = the UTM Zone 11 North easting, UTM Zone 11 North northing and HAE of the last lidar return; and
Columns 8 & 9 = the laser backscatter intensity of the first and last returns.
5
Heights above the GRS80 ellipsoid (HAE) were converted to orthometric heights with respect to the North American Vertical Datum of
1988 (NAVD88), using the GEOID99 model. GPS time tags were used to separate the data collected on a single day into distinct passes.
The resulting pass data sets were then parsed into 3.75-minute USGS quarter-quadrangle components containing the complete point cloud.
Each output file includes data points found within a 20 meter buffer area surrounding each quarter quadrangle. Outlier data points
that exceeded designated elevation thresholds (< -20 m or > 250 m) were eliminated during the parsing process.
6
The NOAA Office for Coastal Management (OCM) received the lidar files in ASCII format. The files contained lidar intensity
and elevation measurements. OCM performed the following processing for data storage and Digital Coast provisioning purposes:
1. Data converted from UTM coordinates to geographic coordinates.
2. Data converted from NAVD88 heights to ellipsoid heights using GEOID99.
3. Data converted from dual return xyz format to xyz text format with return numbers to las format.
4. The LAS data were sorted by latitude and the headers were updated.
2011-03-01T00:00:00
gov.noaa.nmfs.inport:50015
Anne Ball
2017-11-15T15:23:45
SysAdmin InPortAdmin
2022-08-09T17:11:37
2022-03-16
OCM Partners
OCMP
1002
Public
No
2022-03-16
1 Year
2023-03-16