2006 Texas Water Development Board (TWDB) Lidar: Galveston County
Data Set (DS) | OCM Partners (OCMP)GUID: gov.noaa.nmfs.inport:50037 | Updated: August 9, 2022 | Published / External
Summary
Short Citation
OCM Partners, 2024: 2006 Texas Water Development Board (TWDB) Lidar: Galveston County, https://www.fisheries.noaa.gov/inport/item/50037.
Full Citation Examples
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 Galveston County, TX (approximately 400 square miles). Multiple returns
were recorded for each laser pulse along with an intensity value for each return. The data acquisition occurred in missions
during the fall of 2006. The data was collected by Sanborn Mapping Company, Inc. for the Texas Water Development Board (TWDB)
and the Federal Emergency Management Agency (FEMA).
Original contact information:
Contact Name: Ryan Mitchell
Contact Org: Texas Natural Resources Information System (TNRIS)
Phone: 512-463-8337
Email: lidar@tnris.state.tx.us
Distribution Information
-
Create custom data files by choosing data area, product type, map projection, file format, datum, etc.
-
Simple download of data files.
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this data may no longer represent actual surface conditions.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.
Controlled Theme Keywords
elevation
Child Items
No Child Items for this record.
Contact Information
Point of Contact
NOAA Office for Coastal Management (NOAA/OCM)
coastal.info@noaa.gov
(843) 740-1202
Metadata Contact
NOAA Office for Coastal Management (NOAA/OCM)
coastal.info@noaa.gov
(843) 740-1202
Extents
-95.234392° W,
-94.368692° E,
29.599865° N,
29.080365° S
2006-09-01 - 2006-09-30
Item Identification
| Title: | 2006 Texas Water Development Board (TWDB) Lidar: Galveston County |
|---|---|
| Short Name: | tx2006_galveston_m89_metadata |
| Status: | Completed |
| Publication Date: | 2007-08 |
| Abstract: |
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 Galveston County, TX (approximately 400 square miles). Multiple returns were recorded for each laser pulse along with an intensity value for each return. The data acquisition occurred in missions during the fall of 2006. The data was collected by Sanborn Mapping Company, Inc. for the Texas Water Development Board (TWDB) and the Federal Emergency Management Agency (FEMA). Original contact information: Contact Name: Ryan Mitchell Contact Org: Texas Natural Resources Information System (TNRIS) Phone: 512-463-8337 Email: lidar@tnris.state.tx.us |
| Purpose: |
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. |
| Notes: |
10681 |
| Supplemental Information: |
The Galveston County data set was received from the Texas Water Development Board (TWDB). It was reviewed by the NOAA Office for Coastal Management at the macro level, which included checking for format and point characteristics for approximately 5% of the tiles. In addition, the entire data set was reviewed to establish that bare earth processing and proper classification of the points had been performed. It did 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 good quality. This determination is based on the issues listed under the reviews below. Again, no accuracy assessment was performed. The results may be viewed as a formatted document. This document is entitled "Lidar Fact Sheet: Galveston County, Texas," and may be viewed at: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/89/supplemental/GalvestonCounty_factsheet.pdf Tile Review Some minor formatting issues were noted: 1) no flightline source information 2) a low number of second returns Water was, for the most part, classified as "unclassified," which is acceptable; however, it does not conform to the American Society of Photogrammetry and Remote Sensing (ASPRS) standard of class 9 for water values. Bare Earth Point Density Review The major data issue appeared to be at the southeastern portion of the county where water was poorly classified and there was a low bare-earth point density (See Figure 1 of the pdf). Along the bay side of Galveston Island, a few areas appear to lack data. Additionally, a strip on the western edge of the county has lower bare-earth point density and appears to be a processing and data collection attribute. A footprint of this data set may be viewed in Google Earth at: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/89/supplemental/2006_TWDB_Lidar_Galveston_County.kmz |
Keywords
Theme Keywords
| Thesaurus | Keyword |
|---|---|
| ISO 19115 Topic Category |
elevation
|
| UNCONTROLLED | |
| None | Drainage Area |
| None | Hydraulic |
| None | Hydrographic |
| None | Hydrology |
| None | TNRIS (Texas Natural Resources Information System) |
Physical Location
| Organization: | Office for Coastal Management |
|---|---|
| City: | Charleston |
| State/Province: | SC |
Data Set Information
| Data Set Scope Code: | Data Set |
|---|---|
| Maintenance Frequency: | None Planned |
| Distribution Liability: |
Any conclusions drawn from the analysis of this information are not the responsibility of the Office for Coastal Management or its partners. |
| Data Set Credit: | 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. |
Support Roles
Data Steward
| Date Effective From: | 2007-08 |
|---|---|
| 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
| Date Effective From: | 2007-08 |
|---|---|
| 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
| Date Effective From: | 2007-08 |
|---|---|
| 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
| Date Effective From: | 2007-08 |
|---|---|
| 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: | Publication Date |
|---|
Extent Group 1
Extent Group 1 / Geographic Area 1
| W° Bound: | -95.234392 | |
|---|---|---|
| E° Bound: | -94.368692 | |
| N° Bound: | 29.599865 | |
| S° Bound: | 29.080365 |
Extent Group 1 / Time Frame 1
| Time Frame Type: | Range |
|---|---|
| Start: | 2006-09-01 |
| End: | 2006-09-30 |
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: |
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
| Download URL: | https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=89 |
|---|---|
| Distributor: | |
| File Name: | Customized Download |
| Description: |
Create custom data files by choosing data area, product type, map projection, file format, datum, etc. |
Distribution 2
| Download URL: | https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/89/index.html |
|---|---|
| Distributor: | |
| File Name: | Bulk Download |
| Description: |
Simple download of data files. |
URLs
URL 1
| URL: | https://coast.noaa.gov/dataviewer |
|---|---|
| URL Type: |
Online Resource
|
URL 2
| URL: | https://coast.noaa.gov |
|---|---|
| URL Type: |
Online Resource
|
Activity Log
Activity Log 1
| Activity Date/Time: | 2016-05-23 |
|---|---|
| Description: |
Date that the source FGDC record was last modified. |
Activity Log 2
| 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
| Activity Date/Time: | 2018-02-08 |
|---|---|
| Description: |
Partial upload of Positional Accuracy fields only. |
Activity Log 4
| Activity Date/Time: | 2018-03-13 |
|---|---|
| Description: |
Partial upload to move data access links to Distribution Info. |
Technical Environment
| Description: |
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.2.1350 |
|---|
Data Quality
| Horizontal Positional Accuracy: |
FEMA LiDAR Specifications |
|---|---|
| Vertical Positional Accuracy: |
FEMA LiDAR Specifications; +/- 18 cm in open terrain |
| Completeness Report: |
None |
| Conceptual Consistency: |
None |
Lineage
Process Steps
Process Step 1
| Description: |
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 Galveston County, TX (approximately 400 square miles). Multiple returns were recorded for each laser pulse along with an intensity value for each return. The data acquisition occurred in missions during the fall of 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. |
|---|---|
| Process Date/Time: | 2007-08-01 00:00:00 |
Process Step 2
| Description: |
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. |
|---|---|
| Process Date/Time: | 2007-08-01 00:00:00 |
Process Step 3
| Description: |
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. |
|---|---|
| Process Date/Time: | 2007-08-01 00:00:00 |
Process Step 4
| Description: |
Reflective Surface Generation: The reflective surface is derived using the ALS Post Processor software by Leica Geosystems GIS & Mapping Division of Atlanta, Georgia. |
|---|---|
| Process Date/Time: | 2007-08-01 00:00:00 |
Process Step 5
| Description: |
LIDAR Point Classification The classification and quality control (QC) of LiDAR data is carried out using TerraScan software by Terrasolid Limited of Helsinki, Finland. |
|---|---|
| Process Date/Time: | 2007-08-01 00:00:00 |
Process Step 6
| Description: |
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. |
|---|---|
| Process Date/Time: | 2007-08-01 00:00:00 |
Process Step 7
| Description: |
The NOAA Office for Coastal Management (OCM) 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. OCM performed the following processing to the data to make it available within the Digital Coast: 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. NOAA OCM also performed a macro level review of this data set. This review involved checking for format and point characteristics in about 5% of the tiles. In addition, the entire data set was reviewed to establish that bare-earth processing and proper classification of the points had been performed. This review did not include accuracy or data-processing (e.g., bare-earth quality, flightline mismatch, feature removal) assessments. Please refer to the Supplemental_Information field for more information about this review. |
|---|---|
| Process Date/Time: | 2008-08-13 00:00:00 |
Catalog Details
| Catalog Item ID: | 50037 |
|---|---|
| GUID: | gov.noaa.nmfs.inport:50037 |
| 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 |