gov.noaa.csc.maps:2006_TX_Aransas_Refugio_m96
Texas Water Development Board (TWDB)
200708
2006 Texas Water Development Board (TWDB) Lidar: Aransas and Refugio Counties
Charleston, SC
NOAA's Ocean Service (NOS), Coastal Services Center (CSC)
http://www.csc.noaa.gov/lidar
Using a LH Systems ALS50 Light Detection And Ranging (LiDAR) system, flight lines of standard density (1.4 meter ground sample distance) data were collected over areas in Aransas and Refugio Counties, TX (approximately 282 square miles). Multiple returns were recorded for each laser pulse along with an intensity value for each return. The data acquisition occurred in missions in 2006. The data was collected by Sanborn Mapping Company, Inc. for the Texas Water Development
Board (TWDB)and the Federal Emergency Management Agency (FEMA).
This LIDAR operation was designed to provide a high density set of masspoints within the defined areas. The data sets are suitable for the development of contours for use in hydraulic/hydrologic model development, and for assessing environmental impacts. Typical uses for the data set include: FEMA Flood Plain Map Modernization, DFIRM map updates, watersheds and other hydro studies per FEMA specifications, county mapping projects, and flood mitigation assessment.
The Aransas and Refugio Counties data set was received from the Texas Water Development Board (TWDB). It was reviewed by the NOAA Coastal Services Center at the macro level, which includes checking for format and point characteristics for approximately 5% of the tiles. In addition, the entire data set is reviewed to establish that bare earth processing and proper classification of the points has been performed. It does not include accuracy or data processing (e.g. bare
earth quality, flightline mismatch, feature removal) assessments. Based on the limited review, the data set on average appeared to be of fair quality. Again, no accuracy assessment was performed. The results of this review are detailed below. The results may also be viewed as a formatted document. This document is entitled "Aransas and Refugio Counties, Texas: Lidar Fact Sheet," and may be viewed at:
ftp://ftp.csc.noaa.gov/pub/crs/beachmap/qa_docs/tx/aransas_refugio/aransas_refugio_fact-sheet.doc One aspect of the review included a bare earth point density review. A graphic was created that displays the bare earth point density per 2500 sq meter cell and per sq meter. The issues determined in this part of the review were: 1. The areas offshore that have water points classified as bare earth. This can be seen in the amount of salmon colored cells that occur offshore. 2. Also
of note are the dark green cells that follow particular flightlines in the eastern part of the data set. It appears that the points in these flightlines may have been classified differently than points in the rest of the data set. This may be a result of data processing differences. 3. Red areas (low bare earth point density) correspond to vegetated/forested areas, as would be expected. The graphic of this bare earth point density file may be viewed in GoogleEarth at:
ftp://ftp.csc.noaa.gov/pub/crs/beachmap/qa_docs/tx/aransas_refugio/aran_ref.kmz
20060601
20060615
Publication date
None planned
-97.538724
-96.788924
28.562486
27.812486
ISO 19115 Topic Category
Elevation
None
Bathymetry/Topography
DEM
Digital elevation model
Elevation
Digital terrain model
Surface Model
Hydraulic
Hydrographic
Lidar
Hydrologic Modeling
Drainage Area
Hydrology
TNRIS (Texas Natural Resources Information System)
None
United States
Texas
Aransas County
Refugio County
None
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.
Ryan Mitchell
Texas Natural Resources Information System (TNRIS)
Mailing and physical address
1700 N. Congress Ave.
Austin
Texas
78711
United States
512-463-8337
512-463-7274
lidar@tnris.state.tx.us
Data collected by Sanborn Mapping Company, Inc. for the Texas Water Development Board (TWDB) and the Federal Emergency Management Agency (FEMA). Acknowledgement of TNRIS (Texas Natural Resources Information System) would be appreciated in products derived and used from this data. Sanborn Mapping Company asks to be credited in derived products.
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.2.1350
None
None
FEMA LiDAR Specifications
FEMA LiDAR Specifications; +/- 18 cm in open terrain
Data Collection: Using a LH Systems ALS50 Light Detection And Ranging (LiDAR) system, flight lines of standard density (1.4 meter ground sample distance) data were collected over areas in Aransas and Refugio Counties, TX (approximately 282 square miles). Multiple returns were recorded for each laser pulse along with an intensity value for each return. The data acquisition occurred in missions between XXXX, 2006 and XXXX, 2006. During the LIDAR campaign, the Sanborn
field crew conducted a GPS field survey to establish final coordinates of the ground base stations for final processing of the base-remote GPS solutions.
200708
Jamie Young
Sanborn Mapping
LiDAR Manager
Mailing and physical address
1935 Jamboree Drive
Colorado Springs
Colorado
80920
United States
719-264-5602
719-264-5637
jyoung@sanborn.com
Airborne GPS Processing: Airborne GPS data was differentially processed and integrated with the post processed IMU data to derive a smoothed best estimate of trajectory (SBET). The SBET was used to reduce the LiDAR slant range measurements to a raw reflective surface for each flight line. The overlap between flight lines was removed to provide a homogeneous coverage, and the coverage was classified to extract a bare earth digital elevation model (DEM). Airborne GPS is
differentially processed using the GrafNAV V7.50 software by Waypoint Consulting of Calgary, Alberta, Canada. The PDOP and distance separation is as follows: IMU data is processed using the PosPac V4.2 software by Applanix Corporation of Richmond Hill, Ontario, Canada. The reflective surface is derived using the ALS Post Processor software by Leica Geosystems GIS & Mapping Division of Atlanta, Georgia. The classification and quality control (QC) of LiDAR data is carried
out using TerraScan software by Terrasolid Limited of Helsinki, Finland.
200708
Jamie Young
Sanborn Mapping
LiDAR Manager
Mailing and physical address
1935 Jamboree Drive
Colorado Springs
Colorado
80920
United States
719-264-5602
719-264-5637
jyoung@sanborn.com
IMU data Processing: IMU data provides information concerning roll, pitch and yaw of collection platform during collection event. IMU information allows the pulse vector to be properly placed in 3D space allowing the distance from the aircraft reference point to be properly positioned on the elevation model surface. IMU data is processed using the PosPac V4.2 software by Applanix Corporation of Richmond Hill, Ontario, Canada.
200708
Jamie Young
Sanborn Mapping
LiDAR Manager
Mailing and physical address
1935 Jamboree Drive
Colorado Springs
Colorado
80920
United States
719-264-5602
719-264-5637
jyoung@sanborn.com
Reflective Surface Generation: The reflective surface is derived using the ALS Post Processor software by Leica Geosystems GIS & Mapping Division of Atlanta, Georgia.
200708
Jamie Young
Sanborn Mapping
LiDAR Manager
Mailing and physical address
1935 Jamboree Drive
Colorado Springs
Colorado
80920
United States
719-264-5602
719-264-5637
jyoung@sanborn.com
LIDAR Point Classification The classification and quality control (QC) of LiDAR data is carried out using TerraScan software by Terrasolid Limited of Helsinki, Finland.
200708
Jamie Young
Sanborn Mapping
LiDAR Manager
Mailing and physical address
1935 Jamboree Drive
Colorado Springs
Colorado
80920
United States
719-264-5602
719-264-5637
jyoung@sanborn.com
Output LAS Files The product output of LiDAR data is carried out using TerraScan software by Terrasolid Limited of Helsinki, Finland. LAS Binary, ascii xyz, and intensity images were created.
200708
Jamie Young
Sanborn Mapping
LiDAR Manager
Mailing and physical address
1935 Jamboree Drive
Colorado Springs
Colorado
80920
United States
719-264-5602
719-264-5637
jyoung@sanborn.com
The NOAA Coastal Services Center (CSC) received the files in las format. The files contained Lidar elevation and intensity measurements. The data was in UTM projection, and NAVD88 Geoid 03 vertical datum. CSC performed the following processing to the data to make it available within the LDART Retrieval Tool (LDART): 1. The data were converted from UTM coordinates to geographic coordinates. 2. The data were converted from NAVD88 (orthometric) heights to GRS80
(ellipsoid) heights using Geoid 03. 3. The LAS data were sorted by latitude and the headers were updated.
20080813
Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Coastal Services Center (CSC)
Coastal Elevation Mapping (CEM) Project Scientist
Mailing and physical address
2234 South Hobson Ave.
Charleston
SC
29405-2413
843-740-1200
tcm@csc.noaa.gov
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. The data are currently being served via Digital Coastl at http://www.csc.noaa.gov/digitalcoast/. The data can be used to re-populate the system. The data are provided on this disk 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 are NAD 83, however some are 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.
20060103
DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Pamela Grothe
Mailing and Physical Address
NOAA/NESDIS/NGDC E/GC1 325 Broadway
Boulder
CO
80305-3328
USA
(303) 497-6120
(303) 497-6958
(303) 497-6513
pamela.grothe@noaa.gov
7:30-5:00 Mountain
Contact Data Center
Point
0.000000001
0.000000001
Decimal degrees
North American Datum of 1983
Geodetic Reference System 80
6378137.000000
298.257222
Ellipsoid
0.001
Meters
Explicit elevation coordinate included with horizontal coordinates
Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Coastal Services Center (CSC)
Coastal Elevation Mapping (CEM) Project Scientist
Mailing and physical address
2234 South Hobson Ave.
Charleston
SC
29405-2413
843-740-1200
tcm@csc.noaa.gov
Downloadable Data
Any conclusions drawn from the analysis of this information are not the responsibility of the Coastal Services Center or its partners.
This data can be obtained on-line at the following URL: http://csc-s-maps-q.csc.noaa.gov/dataviewer/viewer.html
DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Pamela Grothe
Mailing and Physical Address
NOAA/NESDIS/NGDC E/GC1 325 Broadway
Boulder
CO
80305-3328
USA
(303) 497-6120
(303) 497-6958
(303) 497-6513
pamela.grothe@noaa.gov
7:30-5:00 Mountain
Contact Data Center
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.
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.
20111119
20111119
20121119
Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Coastal Services Center (CSC)
Coastal Elevation Mapping (CEM) Project Scientist
Mailing and physical address
2234 South Hobson Ave.
Charleston
SC
29405-2413
843-740-1200
tcm@csc.noaa.gov
FGDC Content Standards for Digital Geospatial Metadata
FGDC-STD-001-1998