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(NMMR Metadata gov.noaa.csc.maps:utexas_2002)
Metadata:
Identification Information:
Dataset Identifier:
gov.noaa.csc.maps:utexas_2002
Citation:
Citation Information:
Originator:
Bureau of Economic Geology, University of Texas at Austin
Publication Date:
20061017
Title:
2002 Upper Texas Coast Lidar Point Data, Gulf of Mexico Shoreline
in the Northeast 3.75-Minute Quadrant of the Lake Como
7.5-Minute Quadrangle: Post Fay Survey
Online Linkage:
http://www.csc.noaa.gov/lidar
Description:
Abstract:
This data set contains elevation data derived from a lidar survey
approximately 300m wide of the Gulf of Mexico shoreline in the
Northeast Lake Como quarter-quadrangle on Galveston Island Texas.
The geographic extent of the data set is equivalent to the
quarter-quadrangle plus 30 meters of overedge. The data is 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). This system is installed in a single engine Cessna 206
(tail number N4589U) owned and operated by the Texas State
Aircraft Pooling Board. The lidar data described by this document
was collected on 18 September 2002 (26102) between 20:34 and 00:08
UTC (actual data collection). Conditions on that day were low
clouds at 335m Above Ground Level (AGL), haze, and occasional
showers. 99d118 instrument settings for this flight were; laser
pulse rate: 25kHz, scanner rate: 26Hz, scan angle: +/-20deg, beam
divergence: wide, altitude: 300-490m AGL, and ground speed:
70-106kts. Three GPS base stations, 2 Ashtech and 1 Trimble
4000SSI receivers (backup), were operating during the survey. The
three base stations were at the following locations: one 3.5km
south of San Luis Pass, one at the Scholes International Airport
Galveston, and one on the seawall at Rollover Pass.
This data set consists of 1687100 records of x,y, and z values. The
data set was generated from a larger data set and includes all
valid points within the requested geographic bounds.
Purpose:
The data described in this document are being used to create Digital
Elevation Models of the Texas Coast. The DEMs are being used to
map the position of the shoreline along the Gulf of Mexico coast
of Texas for determining rates of shoreline change following
Tropical Storm Fay (September 2002).
Supplemental Information:
The ALTM 1225 has the following specifications: operating altitude =
410-2,000 m AGL; 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 = 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.
Time Period of Content:
Time Period Information:
Single Date/Time:
Calendar Date:
20020918
Currentness Reference:
ground condition
Status:
Progress:
Complete
Maintenance and Update Frequency:
None planned, as needed
Spatial Domain:
Bounding Coordinates:
West Bounding Coordinate:
-95.568694
East Bounding Coordinate:
-93.831419
North Bounding Coordinate:
29.688483
South Bounding Coordinate:
28.797218
Keywords:
Theme:
Theme Keyword Thesaurus:
GCMD
Theme Keyword:
EARTH SCIENCE > LAND SURFACE > Topography > Terrain Elevation
Theme:
Theme Keyword Thesaurus:
None
Theme Keyword:
lidar
Theme Keyword:
laser
Theme Keyword:
beach
Theme Keyword:
topography
Theme Keyword:
digital elevation model
Theme Keyword:
DEM
Theme Keyword:
erosion
Place:
Place Keyword Thesaurus:
none
Place Keyword:
Gulf of Mexico
Place Keyword:
Texas
Place Keyword:
Galveston Island
Place Keyword:
Lake Como
Temporal:
Temporal Keyword Thesaurus:
none
Temporal Keyword:
2002
Access Constraints:
None
Use Constraints:
These data were collected for the purpose of determining amounts and
rates of shoreline change along the Upper Gulf of Mexico coast of
Texas following Tropical Storm Fay, September 2002. 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
or the NOAA Coastal Services Center.
Point of Contact:
Contact Information:
Contact Person Primary:
Contact Person:
Jim Gibeaut
Contact Organization:
Bureau of Economic Geology University of Texas at Austin
Contact Position:
Research Associate
Contact Address:
Address Type:
mailing address
Address:
University Station Box X
City:
Austin
State or Province:
Texas
Postal Code:
78713
Country:
United States
Contact Voice Telephone:
512-471-0344
Contact Facsimile Telephone:
512-471-0140
Contact Electronic Mail Address:
jim.gibeaut@beg.utexas.edu
Data Set Credit:
Bureau of Economic Geology, University of Texas at Austin: J. Gibeaut,
R. Gutierrez, J. Andrews, T. Hepner, and R. Smyth
Data Quality Information:
Logical Consistency Report:
Not applicable
Completeness Report:
Data were edited to remove outliers with ranges above of 2200m and below
100m.
Positional Accuracy:
Horizontal Positional Accuracy:
Horizontal Positional Accuracy Report:
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:
Vertical Positional Accuracy Report:
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 0.01-0.05m. Roads,
which are open areas with an unambiguous surface, were 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 2002
lidar data set was determined to have an elevation bias of
0.06m when compared to ground truth. The 0.06m bias was removed
so that mean lidar elevations conform to NAVD88 with an RMSE of
0.103m.
Lineage:
Source Information:
Source Citation:
Citation Information:
Originator:
Bureau of Economic Geology, University of Texas at Austin
Publication Date:
20020918
Title:
Raw lidar data output from ALTM 1225
Type of Source Media:
digital file
Source Time Period of Content:
Time Period Information:
Single Date/Time:
Calendar Date:
20020918
Source Currentness Reference:
ground condition
Source Citation Abbreviation:
LIDAR
Source Contribution:
raw lidar data from ALTM 1225
Source Information:
Source Citation:
Citation Information:
Originator:
Bureau of Economic Geology, University of Texas at Austin
Publication Date:
20020918
Title:
Air and Ground GPS files from 26102
Type of Source Media:
digital file
Source Time Period of Content:
Time Period Information:
Single Date/Time:
Calendar Date:
20020918
Source Currentness Reference:
ground condition
Source Citation Abbreviation:
GPS
Source Contribution:
air and ground GPS files
Process Step:
Process Description:
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).
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).
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.
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. Then generate
entire lidar point file (9-column ASCII file).
Transfer point file from NT workstation to UNIX workstation. Parse
the 9-column lidar point file into 3.75-minute
quarter-quadrangle components and apply elevation bias
correction (determined during calibration step). 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.
Processing done over 20020918-20030211.
Source Used Citation Abbreviation:
GPS, LIDAR
Process Date:
20030211
Process Contact:
Contact Information:
Contact Person Primary:
Contact Person:
Roberto Guiterrez and John Andrews
Contact Organization:
Bureau of Economic Geology, The University of Texas at
Austin
Contact Position:
Research Associate and Research Scientist Associate
Contact Address:
Address Type:
mailing address
Address:
University Station Box X
City:
Austin
State or Province:
Texas
Postal Code:
78713
Country:
United States
Contact Voice Telephone:
Roberto: 512-471-0342
John: 512-471-4951
Contact Facsimile Telephone:
512-471-0140
Contact Electronic Mail Address:
Roberto: oskar@mail.utexas.edu
John: john.andrews@beg.utexas.edu
Process Step:
Process Description:
The 9-column post-processed data from University of Texas were
provided in UTM projection (Zone 15) referenced to NAD83 with
vertical elevations in meters referenced to the Geodetic
Reference System 80 (GRS80) ellipsoid. The xyz values for the
last return were extracted from the 9-column file. The data
were converted to geographic coordinates using General
Cartographic Transformation Program software developed by the
United States Geological Survey. A vertical datum
transformation was performed to convert vertical elevations
referenced to GRS80 ellipsoid to NAVD88 using National Geodetic
Survey (NGS) GEOID99 grids. The data were then converted to a
binary format and loaded into the LIDAR Data Retrieval Tool
(LDART) database.
Process Date:
20030224
Process Contact:
Contact Information:
Contact Organization Primary:
Contact Organization:
Coastal Remote Sensing Program
Contact Position:
TCM Project Scientist
Contact Address:
Address Type:
mailing and physical address
Address:
2234 South Hobson Avenue
City:
Charleston
State or Province:
South Carolina
Postal Code:
29405
Country:
United States
Contact Voice Telephone:
(843) 740-1200
Contact Electronic Mail Address:
csc@csc.noaa.gov
Process Step:
Process Description:
The NOAA National Geophysical Data Center (NGDC) received Lidar
data files on external harddrive. The disk contains LiDAR data
from the NOAA Coastal Services Center. This data is currently
being served via LDART at http://www.csc.noaa.gov/ldart . This
data can be used to re-populate the system. The data are
provided on this disk in two forms, ascii x,y,z data and also
in LAS format. LAS format is an industry standard for serving
LiDAR data. The data are exclusively in geographic coordinates,
however, the datums used vary. Most is NAD 83, however some is
in ITRF. Vertical systems include both ellipsoid (ITRF and NAD
83) and NAVD 88. For NAVD 88 values, Geiod 03 is primarily
used; however, data received in NAVD 88 prior to 2003 was
processed using Geoid 99.
Process Date:
20060103
Process Contact:
Contact Information:
Contact Organization Primary:
Contact Organization:
DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center,
NESDIS, NOAA, U.S. Department of Commerce
Contact Person:
Kelly Stroker
Contact Address:
Address Type:
Mailing and Physical Address
Address:
NOAA/NESDIS/NGDC E/GC1 325 Broadway
City:
Boulder
State or Province:
CO
Postal Code:
80305-3328
Country:
USA
Contact Voice Telephone:
(303) 497-4603
Contact TDD/TTY Telephone:
(303) 497-6958
Contact Facsimile Telephone:
(303) 497-6513
Contact Electronic Mail Address:
kelly.stroker@noaa.gov
Hours of Service:
7:30-5:00 Mountain
Contact Instructions:
Contact Data Center
Spatial Data Organization Information:
Direct Spatial Reference Method:
Point
Spatial Reference Information:
Horizontal Coordinate System Definition:
Geographic:
Latitude Resolution:
8.69318981134661e-10
Longitude Resolution:
7.56221584957098e-10
Geographic Coordinate Units:
Decimal degrees
Geodetic Model:
Horizontal Datum Name:
North American Datum of 1983
Ellipsoid Name:
Geodetic Reference System 80
Semi-major Axis:
6378137
Denominator of Flattening Ratio:
298.257
Vertical Coordinate System Definition:
Altitude System Definition:
Altitude Datum Name:
NAD83 Ellipsoid
Altitude Resolution:
0.01
Altitude Distance Units:
meters
Altitude Encoding Method:
Explicit elevation coordinate included with horizontal coordinates
Distribution Information:
Distributor:
Contact Information:
Contact Organization Primary:
Contact Organization:
NOAA Coastal Services Center
Contact Position:
Coastal Remote Sensing Program Manager
Contact Address:
Address Type:
mailing and physical address
Address:
2234 South Hobson Avenue
City:
Charleston
State or Province:
SC
Postal Code:
29405-2413
Contact Voice Telephone:
none
Contact Electronic Mail Address:
csc@csc.noaa.gov
Distribution Liability:
This data was collected for the purpose of determining amounts and rates
of shoreline change along the Upper Gulf of Mexico coast of Texas
following Tropical Storm Fay, September 2002. 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 or
the NOAA Coastal Services Center.
Custom Order Process:
This data can be obtained on-line at the following URL:
http://www.csc.noaa.gov/ldart.
Distribution Information:
Distributor:
Contact Information:
Contact Organization Primary:
Contact Organization:
DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center,
NESDIS, NOAA, U.S. Department of Commerce
Contact Person:
Kelly Stroker
Contact Address:
Address Type:
Mailing and Physical Address
Address:
NOAA/NESDIS/NGDC E/GC1 325 Broadway
City:
Boulder
State or Province:
CO
Postal Code:
80305-3328
Country:
USA
Contact Voice Telephone:
(303) 497-4603
Contact TDD/TTY Telephone:
(303) 497-6958
Contact Facsimile Telephone:
(303) 497-6513
Contact Electronic Mail Address:
kelly.stroker@noaa.gov
Hours of Service:
7:30-5:00 Mountain
Contact Instructions:
Contact Data Center
Distribution Liability:
Disclaimer While every effort has been made to ensure that these data
are accurate and reliable within the limits of the current state of
the art, NOAA cannot assume liability for any damages caused by any
errors or omissions in the data, nor as a result of the failure of
the data to function on a particular system. NOAA makes no warranty,
expressed or implied, nor does the fact of distribution constitute
such a warranty.
Custom Order Process:
The National Geophysical Data Center serves as the archive for this
LIDAR data. NGDC should only be contacted for this data if it cannot
be obtained from NOAA Coastal Services Center.
Metadata Reference Information:
Metadata Date:
20070319
Metadata Review Date:
20030324
Metadata Contact:
Contact Information:
Contact Organization Primary:
Contact Organization:
NOAA Coastal Services Center
Contact Person:
Keil Schmid
Contact Position:
Metadata Specialist
Contact Address:
Address Type:
mailing and physical address
Address:
2234 South Hobson Avenue
City:
Charleston
State or Province:
SC
Postal Code:
29405-2413
Contact Voice Telephone:
none
Contact Electronic Mail Address:
metadata@csc.noaa.gov
Metadata Standard Name:
FGDC Content Standards for Digital
Geospatial Metadata
Metadata Standard Version:
FGDC-STD-001-1998
