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Short Citation:
OCM Partners, 2023: April 2004 Lidar Point Data of Southern California Coastline: Dana Point to Point La Jolla,

Item Identification

Title: April 2004 Lidar Point Data of Southern California Coastline: Dana Point to Point La Jolla
Short Name: scripps_20040402_m50_metadata
Status: Completed
Publication Date: 2004-06-22

This data set contains lidar point data (Geodetic Coordinates) from a strip of Southern California

coastline (including water, beach, cliffs, and top of cliffs) from Dana Point to La Jolla. The data set was created by combining

data collected using an Optech Inc. Airborne Laser Terrain Mapper (ALTM) 1225 in combination with geodetic quality Global

Positioning System (GPS) airborne and ground-based receivers. The Bureau of Economic Geology, the University of Texas at Austin

owns and operates an ALTM 1225 system (serial number 99d118). The system was installed in a twin engine Partenavia P-68

(tail number N3832K) owned and operated by Aspen Helicopter, Inc. The lidar data set described by this document was collected

on 2 April 2004 between 19:14 and 21:20 UTC. Julian Day 09304 (see Lineage, Source_Information, Source_Contribution for pass

information). Conditions on 4 April were low clouds at 2500-3000 ft and lower over La Jolla. 99d118 instrument settings for

these flights were; laser pulse rate: 25kHz, scanner rate: 26Hz, scan angle: +/- 20deg, beam divergence: narrow, altitude:

300-600m AGL, and ground speed: 95-120kts. Two GPS base stations were operating during each day of the survey, Point Loma

and San Onofre on 08306 and Seal Beach and San Onofre on 08406 (see Lineage, Source_Information, Source_Contribution for

coordinates). Data represented is all points including terrain, vegetation, and structures. This data also contains returns

from the water surface. No processing has been done to remove returns from terrain, vegetation, structures or water surfaces.

Original contact information:

Contact Name: Julie Thomas/Randy Bucciarelli

Contact Org: SCBPS/CDIP, Scripps Institution of Oceanography

Title: Project Managers

Phone: 858-534-3032


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.



Other Citation Details:

quarter quad names: Del Mar, Dana Point, Encinitas, La Jolla, Las Pulgas Canyon, Oceanside, San Clemente, San Luis Rey,

San Onofre Bluff

Supplemental Information:

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 does not digitize and

record the waveform of the laser reflection, but records the range and backscatter intensity of the first and last laser

reflection using a 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.

Wehr, A. and U. Lohr, 1999, Airborne laser scanning - an introduction and overview, ISPRS Journal of Photogrammetry

and Remote Sensing, vol. 54, no.2-3, pp.68-82.


Theme Keywords

Thesaurus Keyword
ISO 19115 Topic Category
None beach
None intensity
None Latitude
None Longitude
None point file
None shoreline

Temporal Keywords

Thesaurus Keyword
None 2004
None April

Physical Location

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

Data Set Information

Data Set Scope Code: Data Set
Maintenance Note:

None planned, as needed

Distribution Liability:

This data was collected in partnership with Scripps Institution of Oceanography,

The University of California, San Diego. Any conclusions drawn from analysis of this information are not the responsibility

of the Bureau of Economic Geology or the University of Texas at Austin, NOAA, the OCM or its partners.

Data Set Credit: SCBPS/CDIP is jointly funded by the US Army Corps of Engineers and the California Department of Boating and Waterways. The initial data are collected by Bureau of Economic Geology, The University of Texas at Austin: R. Gutierrez and T. Hepner. Center for Space Research, The University of Texas at Austin: A. Neuenschwander. Data are further classified and processed by the SCBPS group, located at the Scripps Institution of Oceanography.

Support Roles

Data Steward

CC ID: 686569
Date Effective From: 2004-06-22
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202


CC ID: 686571
Date Effective From: 2004-06-22
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202

Metadata Contact

CC ID: 686572
Date Effective From: 2004-06-22
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202

Point of Contact

CC ID: 686570
Date Effective From: 2004-06-22
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202


Currentness Reference: Ground Condition

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 1137552
W° Bound: -117.712884
E° Bound: -117.249884
N° Bound: 33.466024
S° Bound: 32.838924

Extent Group 1 / Time Frame 1

CC ID: 1137551
Time Frame Type: Discrete
Start: 2004-04-02

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:


Data Access Constraints:


Data Use Constraints:

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 use this data for critical

applications without a full awareness of its limitations.

Distribution Information

Distribution 1

CC ID: 742567
Download URL:
File Name: Customized Download

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

Distribution 2

CC ID: 742568
Download URL:
File Name: Bulk Download

Simple download of data files.



CC ID: 742570
URL Type:
Online Resource


CC ID: 742571
URL Type:
Online Resource

Activity Log

Activity Log 1

CC ID: 686593
Activity Date/Time: 2016-05-23

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 686592
Activity Date/Time: 2017-11-14

Converted from FGDC Content Standards for Digital Geospatial Metadata (version FGDC-STD-001-1998) using '' script. Contact Tyler Christensen (NOS) for details.

Activity Log 3

CC ID: 718607
Activity Date/Time: 2018-02-08

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 742569
Activity Date/Time: 2018-03-13

Partial upload to move data access links to Distribution Info.

Data Quality

Horizontal Positional Accuracy:

Selected portions from each lidar data set (last return only) were used to generate

a 1m x 1m digital elevation model (DEM). Data estimated to have a horizontal accuracy of 0.01-0.03m from ground surveys using

kinematic GPS techniques 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:

Ground GPS surveys were conducted within the lidar survey area to acquire ground "truth"

information. The ground survey points are estimated to have a vertical accuracy of 0.01-to-0.03m. The parking lot at Torrey

Pines State Park was surveyed using kinematic GPS techniques. A lidar data set was sorted to find data points that fell

within 0.5m of a ground GPS survey point. The mean elevation difference between the lidar and the ground GPS was used to

estimate and remove an elevation bias from the lidar. The standard deviation of these elevation differences provides

estimates of the lidar precision. The April 2004 lidar data set was determined to have an elevation bias of 0.153 m in TIM1

and 0.11 m in TIM2 when compared to ground truth. The bias was removed so that mean lidar elevations have a standard deviation

of 0.053 m and a vertical accuracy (1.96*RMSE) of 0.104 m.

Completeness Report:

Data were edited by an automated method to remove obvious outliers above a threshold of 150m.

Conceptual Consistency:

Not Applicable



Air and Ground GPS files from 09304

CC ID: 1137545
Publish Date: 2004-04-02
Extent Type: Discrete
Extent Start Date/Time: 2004-04-02
Source Contribution:

air and ground GPS files

base station coordinates (Easting, Northing, HAE) in NAD83:

Dana Point (DANA) = 434088.848, 3702981.811, 52.916

Point Loma (LOMA) = 477399.6818, 3614791.197, 90.892

| Type of Source Media: digital file

Raw lidar data output from ALTM 1225

CC ID: 1137546
Publish Date: 2004-04-02
Extent Type: Discrete
Extent Start Date/Time: 2004-04-02
Source Contribution:

raw lidar data from ALTM 1225


Pass 1 (Carlsbad to Scripps Pier) = 19:18-19:26 UTC

Pass 2 (Point La Jolla to Dana Point) = 19:29-19:54 UTC

Pass 3 (Dana Point to Point La Jolla) = 19:59-20:25 UTC

Pass 4 (Point La Jolla to Del Mar) = 20:27-20:30 UTC (wide divergence)

2 calibration passes between 20:32-20:35 UTC

Pass 5 (Del Mar to Dana Point) = 20:37-21:02 UTC

Pass 6 (Dana Point to Carlsbad) = 21:03-21:20 UTC

| Type of Source Media: digital file

Process Steps

Process Step 1

CC ID: 1137547

1. Transfer raw ALTM 1225 flight data, airborne GPS data collected at 1 Hz using Ashtech receiver, and ground-based GPS data

collected at 1 Hz using Ashtech and Trimble 4000SSI receivers to NT workstation. Generate decimated lidar point file from

above three data sets using Optech's Realm 2.27 software. This is a 9-column ASCII data set with the following format:

time tag; first pulse Easting, Northing, HAE; last pulse Easting, Northing, HAE; first pulse intensity; and last pulse

intensity. View decimated lidar point file to check data coverage (i.e. sufficient overlap of flight lines and point spacing).

2. Compute base station coordinates using National Geodetic Survey's PAGES software. Computed aircraft trajectories for both

base stations using National Geodetic Survey's KINPOS software. Coordinates for base stations and trajectories are in the

International Terrestrial Reference Frame of 2000 (ITRF2000) datum. Trajectories from both base stations were merged into one.

Weighting for trajectory merge is based upon baseline length (distance from base station) and solution RMS. Transformed

trajectory solution from ITRF2000 to North American Datum of 1983 (NAD83).

3. Use NAD83 trajectories and aircraft inertial measurement unit data in Applanix's POSProc version 2.1.4 to compute an

optimal 50Hz inertial navigation solution.

4. Substitute the aircraft position and attitude information from the inertial navigation solution into Realm 2.27. Extract

calibration area data set from lidar point file for quality control and instrument calibration checks. If necessary,

use multiple iterations to adjust calibration parameters (pitch, roll, and scale) and reprocess sample data set.

Determine and apply bias corrections based upon ground GPS. Then generate entire lidar point file (9-column ASCII file).

5. Use the Geiod99 geoid model to convert from Height Above the GRS80 ellipsoid to elevations with respect to the North

American Vertical Datum 88 (NAVD88).

6. Parse the 9-column lidar point file into 3.75-minute quarter-quadrangle components. There are some points in the file

that only contain 5-columns. These are points that either the first or last pulse was not recorded.

7. UTM Easting and Northing were converted to geodetic latitude and longitude with respect to the GRS80 ellipsoid.

The conversion was computed using the TMGEOD and TCONPC fortran subroutines written by T. Vincenty (NGS). Each record

contains 9 columns of data: time tag (seconds in the GPS week), first return Latitude, first return Longitude,

first return NAVD88, last return Latitude, last return Longitude, last return NAVD88, first return intensity,

and last return intensity. In some cases either the first or last return values may be missing (5 columns).

Latitude and longitude are in decimal degrees with nine significant digits to retain the 0.01m resolution of the UTM

coordinates. West longitude is negative and north latitude is positive.

8. The eighteen UTM quarter-quad files were re-organized into eleven files. UTM quarter-quads files that were delineated

by the same upper and lower latitude bounds were concatenated. The lat-long files were named by the month-year of the

survey (e.g. mar03) and the lower latitude bounding the quarter-quad. Processing occurred 20040402-20040622.

Process Date/Time: 2004-04-02 00:00:00

Process Step 2

CC ID: 1137548

Created initial metadata

Process Date/Time: 2003-04-18 00:00:00

Process Step 3

CC ID: 1137549

The NOAA Office for Coastal Management (OCM) received files in ASCII format. The files contained LiDAR intensity

and elevation measurements. OCM performed the following

processing on the data to make it available within the LiDAR Data Retrieval Tool (LDART)

1. Data returned to ellipsoid heights from NAVD88, using GEOID99.

2. Data converted to LAS format.

3. The LAS data were sorted by latitude and the headers were updated.

Process Date/Time: 2007-07-24 00:00:00

Catalog Details

Catalog Item ID: 50006
GUID: gov.noaa.nmfs.inport:50006
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