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Short Citation:
OCM Partners, 2022: September 2008 Scripps Institute of Oceanography (SIO) Lidar of the Southern California Coastline: Long Beach to US/Mexico Border, https://www.fisheries.noaa.gov/inport/item/50015.

Item Identification

Title: September 2008 Scripps Institute of Oceanography (SIO) Lidar of the Southern California Coastline: Long Beach to US/Mexico Border
Short Name: scripps_200809_m571_metadata
Status: Completed
Publication Date: 2011-03
Abstract:

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

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.

Notes:

10659

Supplemental Information:

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

Keywords

Theme Keywords

Thesaurus Keyword
ISO 19115 Topic Category
elevation
UNCONTROLLED
None Beaches
None Coastal Landforms/Processes
None GPS
None GPS Receivers
None Landforms
None Shorelines

Temporal Keywords

Thesaurus Keyword
UNCONTROLLED
None 2008
None low tide
None September

Physical Location

Organization: Office for Coastal Management
City: Charleston
State/Province: SC

Data Set Information

Data Set Scope Code: Data Set
Maintenance Frequency: As Needed
Distribution Liability:

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.

Data Set Credit: 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.

Support Roles

Data Steward

CC ID: 687035
Date Effective From: 2011-03
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Distributor

CC ID: 687037
Date Effective From: 2011-03
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Metadata Contact

CC ID: 687038
Date Effective From: 2011-03
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Point of Contact

CC ID: 687036
Date Effective From: 2011-03
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Extents

Currentness Reference: Ground Condition

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 1139217
W° Bound: -118.00025
E° Bound: -117.117638
N° Bound: 33.662182
S° Bound: 32.509061

Extent Group 1 / Time Frame 1

CC ID: 1139216
Time Frame Type: Range
Start: 2008-09-29
End: 2008-09-30

Spatial Information

Spatial Representation

Representations Used

Vector: Yes

Access Information

Security Class: Unclassified
Data Access Procedure:

This data can be obtained on-line at the following URL: https://coast.noaa.gov/dataviewer

;

Data Access Constraints:

None

Data Use Constraints:

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.

Distribution Information

Distribution 1

CC ID: 742612
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=571
Distributor:
File Name: Customized Download
Description:

Create custom data files by choosing data area, product type, map projection, file format, datum, etc.

Distribution 2

CC ID: 742613
Download URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/571/index.html
Distributor:
File Name: Bulk Download
Description:

Simple download of data files.

URLs

URL 1

CC ID: 742615
URL: https://coast.noaa.gov/dataviewer
URL Type:
Online Resource

URL 2

CC ID: 742616
URL: https://coast.noaa.gov
URL Type:
Online Resource

Activity Log

Activity Log 1

CC ID: 687096
Activity Date/Time: 2016-05-23
Description:

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 687095
Activity Date/Time: 2017-11-14
Description:

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.

Activity Log 3

CC ID: 718616
Activity Date/Time: 2018-02-08
Description:

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 742614
Activity Date/Time: 2018-03-13
Description:

Partial upload to move data access links to Distribution Info.

Data Quality

Horizontal Positional Accuracy:

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.

Vertical Positional Accuracy:

(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.

Completeness Report:

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.

Conceptual Consistency:

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.

Lineage

Sources

Air and Ground GPS L1, L2, pseudorange and phase files from September 29 & 30, 2008 (Days of Year 273 & 274)

CC ID: 1139207
Extent Type: Range
Extent Start Date/Time: 2008-09-29
Extent End Date/Time: 2008-09-30
Source Contribution:

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

ALTM 1225 range files

CC ID: 1139206
Extent Type: Range
Extent Start Date/Time: 2008-09-29
Extent End Date/Time: 2008-09-30
Source Contribution:

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

GPS Continuously Operating Reference Station (CORS) at Pinyon Flats, CA

CC ID: 1139208
Extent Type: Range
Extent Start Date/Time: 2008-09-29
Extent End Date/Time: 2008-09-30
Source Contribution:

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

Process Steps

Process Step 1

CC ID: 1139209
Description:

ALTM range files were downloaded from the Optech ALTM 1225 system and decoded using Optech's REALM 3.0 tape decode program.

Process Step 2

CC ID: 1139210
Description:

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).

Process Step 3

CC ID: 1139211
Description:

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.

Process Step 4

CC ID: 1139212
Description:

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.

Process Step 5

CC ID: 1139213
Description:

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.

Process Step 6

CC ID: 1139214
Description:

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.

Process Date/Time: 2011-03-01 00:00:00

Catalog Details

Catalog Item ID: 50015
GUID: gov.noaa.nmfs.inport:50015
Metadata Record Created By: Anne Ball
Metadata Record Created: 2017-11-15 15:23+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2022-08-09 17:11+0000
Metadata Record Published: 2022-03-16
Owner Org: OCMP
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Last Review Date: 2022-03-16
Metadata Review Frequency: 1 Year
Metadata Next Review Date: 2023-03-16