Attribution 4.0 (CC BY 4.0)https://creativecommons.org/licenses/by/4.0/
License information was derived automatically
This resource contains Lidar-DEM collection status shapefiles from the Texas Natural Resources Information System (TNRIS) [http://tnris.org]. November 2023 updates: this year, TNRIS changed its name to Texas Geographic Information Office (TxGIO). The domain name hasn't changed yet, but the data hub is continually evolving. See [1], [2] for current downloadable data.
For purposes of Hurricane Harvey studies, the 1-m DEM for Harris County (2008) has also been uploaded here as a set of 4 zipfiles containing the DEM in tiff files. See [1] for a link to the current elevation status map and downloadable DEMs.
Project name: H-GAC 2008 1m
Datasets: 1m Point Cloud, 1M Hydro-Enforced DEM, 3D Breaklines, 1ft and 5ft Contours
Points per sq meter: 1
Total area: 3678.56 sq miles
Source: Houston-Galveston Area Council (H-GAC)
Acquired by: Merrick, QA/QC: Merrick
Catalog: houston-galveston-area-council-h-gac-2008-lidar
References: [1] TNRIS/TxGIO StratMap elevation data [https://tnris.org/stratmap/elevation-lidar/] [2] TNRIS/TxGIO DataHub [https://data.tnris.org/]
The Texas Water Development Board (TWDB) in cooperation with their project partners tasked Fugro Geospatial, Inc. (Fugro) under the Department of Information Resources (DIR) Geographic Information Systems (GIS) Hardware, Software and Services contract also known as the Texas Strategic Mapping (StratMap) Contract to acquire high resolution elevation data and associated products from airborne lid...
U.S. Government Workshttps://www.usa.gov/government-works
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ELEVATION.contours_2021
Summary The Texas Natural Resources Information System (TNRIS) contracted Sanborn to fly LiDAR in March of 2021. TNRIS then created the contours in the Spring of 2022 using Global Mapper.
Description This layer represents contour elevation lines as of the March 2021. The contours are derived from LiDAR data, collected in the March 2021. Contours were generated using Global Mapper, sample spacing used to create the contours is consistent with the Nominal Point Spacing (NPS), of the source LiDAR dataset from which it was derived. Lines were automatically smoothed while being generated by Global Mapper.
Important: The LiDAR data was created using UTM zone 14N and was projected in Central Texas State Plane (NAD 83) FIPS 4203.
For contour type: 1 = Minor Contour 2 = Intermediate Contour 3 = Major Contour
Credits The Texas Natural Resources Information System (TNRIS)
Use limitations This map has been produced by the City of Austin for the cartographic purposes. No warranty is made by the City or TNRIS regarding its accuracy or completeness.
MIT Licensehttps://opensource.org/licenses/MIT
License information was derived automatically
This digital elevation model (DEM) is a part of a series of DEMs produced for the National Oceanic and Atmospheric Administration Coastal Services Center's Sea Level Rise and Coastal Flooding Impacts Viewer. The DEM includes the 'best available' lidar data known to exist at the time of DEM creation that meets project specifications for those counties within the boundary of the Houston/Galveston TX Weather Forecast Office (WFO), as defined by the NOAA National Weather Service. The counties within this boundary are: Jackson, Matagorda, Brazoria (portion), Harris (portion), Galveston, and Chambers. For all the counties listed, except for Harris, the DEM is derived from LiDAR data sets collected for the Texas Water Development Board (TWDB) in 2006 with a point density of 1.4 m GSD. LiDAR data for Harris County was collected in October 2001 by the Harris County Flood Control District Tropical Storm Allison Recovery Project (TSARP) with a point density of 2.0 m GSD. Hydrographic breaklines used in the creation of the DEM were delineated using LiDAR intensity imagery generated from the data sets. The DEM is hydro flattened such that water elevations are less than or equal to 0 meters.The DEM is referenced vertically to the North American Vertical Datum of 1988 (NAVD88) with vertical units of meters and horizontally to the North American Datum of 1983 (NAD83). The resolution of the DEM is approximately 10 meters.
These data were created as part of the National Oceanic and Atmospheric Administration Office for Coastal Management's efforts to create an online mapping viewer called the Sea Level Rise and Coastal Flooding Impacts Viewer. It depicts potential sea level rise and its associated impacts on the nation's coastal areas. The purpose of the mapping viewer is to provide coastal managers and scientists with a preliminary look at sea level rise and coastal flooding impacts. The viewer is a screening-level tool that uses nationally consistent data sets and analyses. Data and maps provided can be used at several scales to help gauge trends and prioritize actions for different scenarios. The Sea Level Rise and Coastal Flooding Impacts Viewer may be accessed at: https://coast.noaa.gov/slr. This metadata record describes the Texas South 1 digital elevation model (DEM), which is a part of a series of DEMs produced for the National Oceanic and Atmospheric Administration Office for Coastal Management's Sea Level Rise and Coastal Flooding Impacts Viewer described above. This DEM includes the best available lidar known to exist at the time of DEM creation that met project specifications. This DEM includes data for Calhoun, Jackson, Matagorda, and Victoria Counties. The DEM was produced from the following lidar data sets: 1. 2018 Texas - South Texas Lidar The DEM is referenced vertically to the North American Vertical Datum of 1988 (NAVD88, Geoid12B) with vertical units of meters and horizontally to the North American Datum of 1983 (NAD83). The resolution of the DEM is approximately 3 meters.
Attribution 4.0 (CC BY 4.0)https://creativecommons.org/licenses/by/4.0/
License information was derived automatically
This lidar dataset was collected as part of an NCALM Rapid Response Project for Inci Gunerlap at Texas A&M University. Data collection covers and area of ~69 km2 along the Mission River in Refugio, Texas after Hurricane Harvey. Note: this project utilized three laser channels during its data collection. Each of the returns contained on the LAS tiles are encoded with a laser channel value. The values used are 1 (1550 nm), 2 (1064 nm), and 3 (532 nm), and are stored in the "User Data" record of the Point Data records in the LAS file. This data collection also contains hyperspectral images that are 72 Band, 1.5 m pixel size, in PCIDSK (.PIX) format. The digital number in the PIX image corresponds to milli-SRU (spectral radiance units). One SRU is equivalent to one microwatt per square-centimeter per steradian per nanometer. Files are provided as individual flight strips as well as a single mosaic file of flight strips. These images can be downloaded here The pre-computed Raster products are split into two separate landing pages: C1-2, and C1-2-3. Pre-computed Raster C1-2 contains the following: DEM from classified ground returns from Channels 1 and 2 (IR only) DSM from first return from Channels 1 and 2 Pre-computed Raster C1-2-3 contains the following: DEM from classified ground and bathymetry returns from all channels DSM from first returns from all channels (C1C2C3) Water surface grid from point class 39 Bathymetry grid from point class 9
Elevation maps (also known as Digital Elevation Models or DEMs) of Padre Island National Seashore were produced from remotely-sensed, geographically-referenced elevation measurements in cooperation with NASA and NPS. Point data in ascii text files were interpolated in a GIS to create a grid or digital elevation model (DEM) of each beach surface. Elevation measurements were collected in Texas, over Padre Island National Seashore, using the NASA Experimental Advanced Airborne Research Lidar (EAARL), a pulsed laser ranging system mounted onboard an aircraft to measure ground elevation and coastal topography. The system uses high frequency laser beams directed at the earth's surface through an opening in the bottom of the aircraft's fuselage. The laser system records the time difference between emission of the laser beam and the reception of the reflected laser signal in the aircraft. The plane travels over the beach at approximately 60 meters per second while surveying from the low-water line to the landward base of the sand dunes. The EAARL, developed by the National Aeronautics and Space Administration (NASA) located at Wallops Flight Facility in Virginia, measures ground elevation with a vertical resolution of 15 centimeters. A sampling rate of 3 kHz or higher results in an extremely dense spatial elevation data set. Over 100 kilometers of coastline can be easily surveyed within a 3- to 4-hour mission time period. The ability to sample large areas rapidly and accurately is especially useful in morphologically dynamic areas such as barrier beaches. Quick assessment of topographic change can be made following storms comparing measurements against baseline data. When subsequent elevation maps for an area are analyzed, they provide a useful tool to make management decisions regarding coastal development. For more information on Lidar science and the Experimental Advanced Airborne Research Lidar (EAARL) system and surveys, see http://ngom.usgs.gov/dsp/overview/index.php and http://ngom.usgs.gov/dsp/tech/eaarl/index.php .
description: This data set was received by the NOAA Office for Coastal Management from the Texas Natural Resources Information System. The data was collected in October of 2001 by Terrapoint USA, Inc. using an Airborne LIDAR Topographic Mapping System (ALTMS). Flight altitude was approximately 915 meters, creating a data swath of approximately 550 meters. The surface elevation value accuracy is better than 15 centimeters. The lidar points are unclassified.; abstract: This data set was received by the NOAA Office for Coastal Management from the Texas Natural Resources Information System. The data was collected in October of 2001 by Terrapoint USA, Inc. using an Airborne LIDAR Topographic Mapping System (ALTMS). Flight altitude was approximately 915 meters, creating a data swath of approximately 550 meters. The surface elevation value accuracy is better than 15 centimeters. The lidar points are unclassified.
description: 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 Jefferson County, TX (approximately 960 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 July 4, 2006, and July 6, 2006. The data was collected by Sanborn Mapping Company, Inc. for the Texas Water Development Board (TWDB) and the Federal Emergency Management Agency (FEMA).; 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 Jefferson County, TX (approximately 960 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 July 4, 2006, and July 6, 2006. The data was collected by Sanborn Mapping Company, Inc. for the Texas Water Development Board (TWDB) and the Federal Emergency Management Agency (FEMA).
description: Using a LH Systems ALS50 Light Detection And Ranging (LiDAR) system, 43 flight lines of standard density (1.4 meter ground sample distance) data were collected over areas in Orange County, TX (approximately 364 square miles). Multiple returns were recorded for each laser pulse along with an intensity value for each return. The data acquisition occurred in 5 missions between June 4, 2006, and June 6, 2006. The data was collected by Sanborn Mapping Company, Inc. for the Texas Water Development Board (TWDB) and the Federal Emergency Management Agency (FEMA).; abstract: Using a LH Systems ALS50 Light Detection And Ranging (LiDAR) system, 43 flight lines of standard density (1.4 meter ground sample distance) data were collected over areas in Orange County, TX (approximately 364 square miles). Multiple returns were recorded for each laser pulse along with an intensity value for each return. The data acquisition occurred in 5 missions between June 4, 2006, and June 6, 2006. The data was collected by Sanborn Mapping Company, Inc. for the Texas Water Development Board (TWDB) and the Federal Emergency Management Agency (FEMA).
These data were created as part of the National Oceanic and Atmospheric Administration Office for Coastal Management's efforts to create an online mapping viewer called the Sea Level Rise and Coastal Flooding Impacts Viewer. It depicts potential sea level rise and its associated impacts on the nation's coastal areas. The purpose of the mapping viewer is to provide coastal managers and scientists with a preliminary look at sea level rise and coastal flooding impacts. The viewer is a screening-level tool that uses nationally consistent data sets and analyses. Data and maps provided can be used at several scales to help gauge trends and prioritize actions for different scenarios. The Sea Level Rise and Coastal Flooding Impacts Viewer may be accessed at: https://coast.noaa.gov/slr. This metadata record describes the Texas North 2 digital elevation model (DEM), which is a part of a series of DEMs produced for the National Oceanic and Atmospheric Administration Office for Coastal Management's Sea Level Rise and Coastal Flooding Impacts Viewer described above. This DEM includes the best available lidar known to exist at the time of DEM creation that met project specifications. This DEM includes data for Brazoria, Chambers, Galveston, Harris, and Liberty Counties. The DEM was produced from the following lidar data sets: 1. 2018 TNRIS Lidar: Upper Coastal Lidar 2. 2017 TNRIS Lidar: Jefferson, Liberty, and Chambers 3. 2016 FEMA Region 6 TX - Neches Basin QL2 Lidar The DEM is referenced vertically to the North American Vertical Datum of 1988 (NAVD88, Geoid12B) with vertical units of meters and horizontally to the North American Datum of 1983 (NAD83). The resolution of the DEM is approximately 3 meters.
description: 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 Brazoria County, TX (approximately 1428 square miles). Multiple returns were recorded for each laser pulse along with an intensity value for each return. The data acquisition occurred in 6 missions between April 9, 2006, April 16, 2006, April 17, 2006, and May 11, 2006 through May 13, 2006. The data was collected by Sanborn Mapping Company, Inc. for the Texas Water Development Board (TWDB) and the Federal Emergency Management Agency (FEMA).; 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 Brazoria County, TX (approximately 1428 square miles). Multiple returns were recorded for each laser pulse along with an intensity value for each return. The data acquisition occurred in 6 missions between April 9, 2006, April 16, 2006, April 17, 2006, and May 11, 2006 through May 13, 2006. The data was collected by Sanborn Mapping Company, Inc. for the Texas Water Development Board (TWDB) and the Federal Emergency Management Agency (FEMA).
description: The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) plans to perform a coastal survey along the Gulf Coast in 2016 with funding provided by the US Army Corps of Engineers (USACE) National Coastal Mapping Program (NCMP). The data types to be collected include bathymetric and topographic lidar point data, down-looking aerial imagery and hyperspectral imagery. The collection effort will follow the coastline and extend 500m inland and 1000m offshore or to bathymetric lidar extinction, whichever comes first. Topographic lidar data will have a nominal sub-meter post-spacing. Where water conditions permit, the bathymetric lidar data will have nominal 2m x 2m postings. Vertical accuracy of the topographic lidar data will meet or exceed RMSEZ=15 cm. Bathymetric lidar data will have a vertical accuracy of 30 cm, 2-sigma. The aerial imagery will have a pixel size approximately 20cm and the hyperspectral imagery will be provided in 1m pixels containing 36 spectral bands between 375 - 1050 nm with 19 nm bandwidth. The data will be collected on the NAD83 ellipsoid using NGS published monuments as control. Final data will be tied horizontally to NAD83 (NSRS 2007) in geographic coordinates. Vertical measurements will be converted from NAD83 ellipsoid heights in meters to NAVD88 orthometric heights using the current Geoid model at the time of acquisition. Data products from this survey effort will include topographic and bathymetric lidar point clouds in LAS format, an NAVD88 0m shoreline contour, and a series of raster data products including topo/bathy digital elevation models (DEMs), true-color aerial image mosaics, hyperspectral image mosaics, laser reflectance images and basic landcover classification images. Images of water column properties (i.e. chlorophyll and CDOM concentrations) will also be generated. Within 6 months of completing the data acquisition, these final data products will be available for public use in the absence of any unforeseen data processing delays.; abstract: The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) plans to perform a coastal survey along the Gulf Coast in 2016 with funding provided by the US Army Corps of Engineers (USACE) National Coastal Mapping Program (NCMP). The data types to be collected include bathymetric and topographic lidar point data, down-looking aerial imagery and hyperspectral imagery. The collection effort will follow the coastline and extend 500m inland and 1000m offshore or to bathymetric lidar extinction, whichever comes first. Topographic lidar data will have a nominal sub-meter post-spacing. Where water conditions permit, the bathymetric lidar data will have nominal 2m x 2m postings. Vertical accuracy of the topographic lidar data will meet or exceed RMSEZ=15 cm. Bathymetric lidar data will have a vertical accuracy of 30 cm, 2-sigma. The aerial imagery will have a pixel size approximately 20cm and the hyperspectral imagery will be provided in 1m pixels containing 36 spectral bands between 375 - 1050 nm with 19 nm bandwidth. The data will be collected on the NAD83 ellipsoid using NGS published monuments as control. Final data will be tied horizontally to NAD83 (NSRS 2007) in geographic coordinates. Vertical measurements will be converted from NAD83 ellipsoid heights in meters to NAVD88 orthometric heights using the current Geoid model at the time of acquisition. Data products from this survey effort will include topographic and bathymetric lidar point clouds in LAS format, an NAVD88 0m shoreline contour, and a series of raster data products including topo/bathy digital elevation models (DEMs), true-color aerial image mosaics, hyperspectral image mosaics, laser reflectance images and basic landcover classification images. Images of water column properties (i.e. chlorophyll and CDOM concentrations) will also be generated. Within 6 months of completing the data acquisition, these final data products will be available for public use in the absence of any unforeseen data processing delays.
Attribution 4.0 (CC BY 4.0)https://creativecommons.org/licenses/by/4.0/
License information was derived automatically
This lidar dataset was collected as part of an NCALM Rapid Response Project for Inci Gunerlap at Texas A&M University. Data collection covers and area of ~69 km2 along the Mission River in Refugio, Texas after Hurricane Harvey. Note: this project utilized three laser channels during its data collection. Each of the returns contained on the LAS tiles are encoded with a laser channel value. The values used are 1 (1550 nm), 2 (1064 nm), and 3 (532 nm), and are stored in the "User Data" record of the Point Data records in the LAS file. This data collection also contains hyperspectral images that are 72 Band, 1.5 m pixel size, in PCIDSK (.PIX) format. The digital number in the PIX image corresponds to milli-SRU (spectral radiance units). One SRU is equivalent to one microwatt per square-centimeter per steradian per nanometer. Files are provided as individual flight strips as well as a single mosaic file of flight strips. These images can be downloaded here The pre-computed Raster products are split into two separate landing pages: C1-2, and C1-2-3. Pre-computed Raster C1-2 contains the following: DEM from classified ground returns from Channels 1 and 2 (IR only) DSM from first return from Channels 1 and 2 Pre-computed Raster C1-2-3 contains the following: DEM from classified ground and bathymetry returns from all channels DSM from first returns from all channels (C1C2C3) Water surface grid from point class 39 Bathymetry grid from point class 9 Publications associated with this dataset can be found at NCALM's Data Tracking Center
MIT Licensehttps://opensource.org/licenses/MIT
License information was derived automatically
This digital elevation model (DEM) is a part of a series of DEMs produced for the National Oceanic and Atmospheric Administration Coastal Services Center's Sea Level Rise and Coastal Flooding Impacts Viewer. The DEM includes 'best available' lidar data known to exist at the time of DEM creation that meets project specifications for those Texas counties that fall within the boundary of the Lake Charles, LA Weather Forecast Office (WFO), as defined by the NOAA National Weather Service: Orange and Jefferson counties. Note that no data for any Louisiana parishes are explicitly included in this feature layer, except for those narrow portions which border the Texas counties that are included herein.The DEM is derived from LiDAR datasets collected for the Texas Water Development Board (TWDB). LiDAR data for Orange and Jefferson counties was collected for the TWDB in 2006. Hydrographic breaklines used in the creation of the DEM were delineated using LiDAR intensity imagery generated from the TWDB datasets. The DEMs are hydro flattened such that water elevations are less than or equal to 0 meters.The DEM is referenced vertically to the North American Vertical Datum of 1988 (NAVD88) with vertical units of meters and horizontally to the North American Datum of 1983 (NAD83). The resolution of the DEM is approximately 10 meters.
The Kerrville 2011 2-ft Contour is intended to be used for general reference and visualization, and is not a substitute for an on-the-ground survey conducted by, or under the supervision of, a registered professional land surveyor.The two foot contours were derived from 2011 lidar data. The lidar was filtered to ground points only and exported to a multipoint dataset. The multipoint dataset, breaklines, and project extent were used to create a terrain dataset. Building footprints were used to remove any points that fell inside a building footprint due to misclassification of the lidar point. A digital elevation model (DEM) was created from the terrain dataset with a 10-ft cell size. The 10-ft DEM was smoothed using focal statistics by averaging a 3x3 cell sized rectangular area across the entire DEM. Contours were created from the smoothed DEM at a two foot interval with a base elevation of 1,500 feet. Contours smaller than 39.5-ft were removed and contours completely within waterbodies were removed. The contours were then split into 20 rows by 10 columns to improve performance. Then the contours were run through a smoothing process to remove sharp bends in the lines without affecting the general location of the lines. Lastly index intervals were calculated for 10-ft, 20-ft, 50-ft, and 100-ft.The lidar collection that the 2ft Contours 2011 was created from was flown and processed by Merrick & Company, covering portions of Blanco, Caldwell, DeWitt, Gonzales, Kendall and Kerr counties in central Texas. Aerial collection took place from January to March 2011 during the leaf-off season. URS provided third-party quality assurance and quality control (QA/QC). The collection was funded by the Floodplain Mapping Group in tandem with the Strategic Mapping Program (StratMap) and were procured through the Council on Competitive Government’s High Priority Imagery and Datasets (HPIDS) contract.
description: A bare-earth topography Digital Elevation Model (DEM) mosaic for the Village Creek Corridor Unit of Big Thicket National Preserve in Texas was produced from remotely sensed, geographically referenced elevation measurements collected on January 19, 21, 22, 23, 26, 27, and 29, 2014 by the U.S. Geological Survey, in cooperation with the National Park Service - Gulf Coast Network. Elevation measurements were collected over the area using the second-generation Experimental Advanced Airborne Research Lidar (EAARL-B), a pulsed laser ranging system mounted onboard an aircraft to measure ground elevation, vegetation canopy, and coastal topography. The system uses high-frequency laser beams directed at the Earth's surface through an opening in the bottom of the aircraft's fuselage. The laser system records the time difference between emission of the laser beam and the reception of the reflected laser signal in the aircraft. The plane travels over the target area at approximately 55 meters per second at an elevation of approximately 300 meters, resulting in a laser swath of approximately 240 meters with an average point density of 1.4 points per square meter. A peak sampling rate of 15-30 kilohertz results in an extremely dense spatial elevation dataset. More than 100 kilometers of coastline can be surveyed easily within a 3- to 4-hour mission. When resultant elevation maps for an area are analyzed, they provide a useful tool to make management decisions regarding land development.; abstract: A bare-earth topography Digital Elevation Model (DEM) mosaic for the Village Creek Corridor Unit of Big Thicket National Preserve in Texas was produced from remotely sensed, geographically referenced elevation measurements collected on January 19, 21, 22, 23, 26, 27, and 29, 2014 by the U.S. Geological Survey, in cooperation with the National Park Service - Gulf Coast Network. Elevation measurements were collected over the area using the second-generation Experimental Advanced Airborne Research Lidar (EAARL-B), a pulsed laser ranging system mounted onboard an aircraft to measure ground elevation, vegetation canopy, and coastal topography. The system uses high-frequency laser beams directed at the Earth's surface through an opening in the bottom of the aircraft's fuselage. The laser system records the time difference between emission of the laser beam and the reception of the reflected laser signal in the aircraft. The plane travels over the target area at approximately 55 meters per second at an elevation of approximately 300 meters, resulting in a laser swath of approximately 240 meters with an average point density of 1.4 points per square meter. A peak sampling rate of 15-30 kilohertz results in an extremely dense spatial elevation dataset. More than 100 kilometers of coastline can be surveyed easily within a 3- to 4-hour mission. When resultant elevation maps for an area are analyzed, they provide a useful tool to make management decisions regarding land development.
Spectrum Mapping, LLC was tasked by MAPVI - URS Corporation, Albuquergue, to provide airborne Light Detection and Ranging (Lidar) of approximately 620 square miles around Nueces County, Texas. MAPVI (Mapping Alliance Partnership VI for FEMA Region IV) is a joint venture of URS Corporation, Greenhorne & O'Mara and Spectrum Mapping. Spectrum followed data collection and processing procedures for...
A bare-earth topography Digital Elevation Model (DEM) mosaic for the Little Pine Island Bayou Corridor Unit of Big Thicket National Preserve in Texas was produced from remotely sensed, geographically referenced elevation measurements collected on January 15, 21, 22, 26, and 30, 2014 by the U.S. Geological Survey, in cooperation with the National Park Service - Gulf Coast Network. Elevation measurements were collected over the area using the second-generation Experimental Advanced Airborne Research Lidar (EAARL-B), a pulsed laser ranging system mounted onboard an aircraft to measure ground elevation, vegetation canopy, and coastal topography. The system uses high-frequency laser beams directed at the Earth's surface through an opening in the bottom of the aircraft's fuselage. The laser system records the time difference between emission of the laser beam and the reception of the reflected laser signal in the aircraft. The plane travels over the target area at approximately 55 meters per second at an elevation of approximately 300 meters, resulting in a laser swath of approximately 240 meters with an average point density of 1.4 points per square meter. A peak sampling rate of 15-30 kilohertz results in an extremely dense spatial elevation dataset. More than 100 kilometers of coastline can be surveyed easily within a 3- to 4-hour mission. When resultant elevation maps for an area are analyzed, they provide a useful tool to make management decisions regarding land development.
Link to the ScienceBase Item Summary page for the item described by this metadata record. Service Protocol: Link to the ScienceBase Item Summary page for the item described by this metadata record. Application Profile: Web Browser. Link Function: information
Attribution 4.0 (CC BY 4.0)https://creativecommons.org/licenses/by/4.0/
License information was derived automatically
This resource contains Lidar-DEM collection status shapefiles from the Texas Natural Resources Information System (TNRIS) [http://tnris.org]. November 2023 updates: this year, TNRIS changed its name to Texas Geographic Information Office (TxGIO). The domain name hasn't changed yet, but the data hub is continually evolving. See [1], [2] for current downloadable data.
For purposes of Hurricane Harvey studies, the 1-m DEM for Harris County (2008) has also been uploaded here as a set of 4 zipfiles containing the DEM in tiff files. See [1] for a link to the current elevation status map and downloadable DEMs.
Project name: H-GAC 2008 1m
Datasets: 1m Point Cloud, 1M Hydro-Enforced DEM, 3D Breaklines, 1ft and 5ft Contours
Points per sq meter: 1
Total area: 3678.56 sq miles
Source: Houston-Galveston Area Council (H-GAC)
Acquired by: Merrick, QA/QC: Merrick
Catalog: houston-galveston-area-council-h-gac-2008-lidar
References: [1] TNRIS/TxGIO StratMap elevation data [https://tnris.org/stratmap/elevation-lidar/] [2] TNRIS/TxGIO DataHub [https://data.tnris.org/]