50048
2011 ARRA Lidar: Willacy County (TX)
tx2011_arra_willacy_m4988_metadata
Data Set
Published / External
49401
Lidar - partner (no harvest)
Project
Completed
2016-01-09
This task order is for planning, acquisition, processing, and derivative products of LiDAR data to be collected for a portion of Willacy County, Texas. LiDAR data, and derivative products produced in compliance with this task order are part of the data to be obtained under the American Recovery and Reinvestment Act (ARRA) of 2009. Contract number G10PC00025. Specifications listed below are based on the U.S. Geological Survey National Geospatial Program Base LiDAR Specification, Version 13. Tile names were slightly altered to meet particular naming conventions on NOAA OCM ftp. Dataset is titled 2010 but due to acquisition dates falling in 2011, the name has been updated.
Original contact information:
Contact Name: Patrick Emmett
Contact Org: USGS
Title: USGS NGTOC
Phone: 573-308-3587
Email: pemmett@usgs.gov
USGS has a requirement for LiDAR data over a portion of Willacy County in Texas, covering approximately 501 square miles. Willacy County is to be collected at a nominal pulse spacing (NPS) of 2.0 meters. The Willacy County Texas LiDAR Acquisition project is to provide high accuracy bare-earth processed LiDAR data suitable for the project area. The project consisted of acquisition, post-processing, classification of LiDAR data, and creation of final deliverable products. All areas shall be collected at a nominal pulse spacing (NPS) of 2.0 meters based on UTM14, related to the North American Datum of 1983 (NSRS2007). Vertical accuracy was to achieve a RMSE Z of 12.5 cm (95% confidence level of less than 24.5 cm) or better in the "Open Terrain" land cover category for all areas. Accuracy statement is based on areas of moderate to flat terrain. Diminished accuracies are to be expected in areas in dense vegetation. The accuracy of the LiDAR data as tested met or exceeded the vertical accuracy requirements, however, derived products may be less accurate in areas of dense vegetation due to a lesser number of points defining the bare-earth in such areas.
10692
A footprint of this data set may be viewed in Google Earth at:
https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/4988/supplemental/tx2010_arra_willacy_m4988.kmz
Reports explaining collection and quality assurance is available at:
https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/4988/supplemental/tx2010_arra_willacy_m4988_lidarreport.pdf
Theme
ISO 19115 Topic Category
elevation
Office for Coastal Management
Charleston
SC
Data Set
As Needed
las
LiDAR points in LAZ format (Classes 1,2,7,9,10)
none
Any conclusions drawn from the analysis of this information are not the responsibility of AeroMetric, USGS, NOAA, the Office for Coastal Management or its partners.
Data Steward
2016-01-09
Organization
NOAA Office for Coastal Management
NOAA/OCM
coastal.info@noaa.gov
2234 South Hobson Ave
Charleston
SC
29405-2413
(843) 740-1202
https://coast.noaa.gov
NOAA Office for Coastal Management Home Page
Online Resource
Distributor
2016-01-09
Organization
NOAA Office for Coastal Management
NOAA/OCM
coastal.info@noaa.gov
2234 South Hobson Ave
Charleston
SC
29405-2413
(843) 740-1202
https://coast.noaa.gov
NOAA Office for Coastal Management Home Page
Online Resource
Metadata Contact
2016-01-09
Organization
NOAA Office for Coastal Management
NOAA/OCM
coastal.info@noaa.gov
2234 South Hobson Ave
Charleston
SC
29405-2413
(843) 740-1202
https://coast.noaa.gov
NOAA Office for Coastal Management Home Page
Online Resource
Point of Contact
2016-01-09
Organization
NOAA Office for Coastal Management
NOAA/OCM
coastal.info@noaa.gov
2234 South Hobson Ave
Charleston
SC
29405-2413
(843) 740-1202
https://coast.noaa.gov
NOAA Office for Coastal Management Home Page
Online Resource
Ground Condition
-98.01204
-97.22332
26.615044
26.371022
Range
2011-02-01
2011-03-02
Yes
Unclassified
This data can be obtained on-line at the following URL:
https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=4988;
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. These data depict the heights at the time of the survey and are only accurate for that time.
https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=4988
Customized Download
Create custom data files by choosing data area, product type, map projection, file format, datum, etc.
https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/4988/index.html
Bulk Download
Simple download of data files.
https://coast.noaa.gov
Online Resource
https://coast.noaa.gov/dataviewer
Online Resource
https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/4988/supplemental/1101205_Willacy_LiDAR_Processing_Report.pdf
Lidar Report
Online Resource
pdf
Link to the lidar report.
2016-05-23
Date that the source FGDC record was last modified.
2017-11-14
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.
2018-02-08
Partial upload of Positional Accuracy fields only.
2018-03-13
Partial upload to move data access links to Distribution Info.
The Fundamental Vertical Accuracy (FVA) of the Classified Bare Earth files for the project area achieved an RMSE of 0.088 meters. Forty-five (45) 'open terrain' survey control points were used in this evaluation, with an additional 20 'open terrain' points held in reserve and supplied to the client. Additional survey control points were also supplied to the client with 20 points in the category of 'short grass' and 18 points in the category of 'tall grass'.
All Area data products were acquired at or below 2500 meters above mean terrain (AMT) and have a horizontal accuracy of 0.45 meters (per manufacturers system specifications), with a nominal point spacing of 1.5 meters.
The Fundamental Vertical Accuracy (FVA) of the Classified Bare Earth for all Areas achieved is 0.172 meters at a 95% confidence level in the "Open Terrain" land cover category. Forty-five (45) survey control points were used in this evaluation.; Quantitative Value: 0.172 meters, Test that produced the value: FVA of 17.2 cm. 0.088 m RMSEz (1.96xRMSEz)
Complete
None
1
The LiDAR data was captured using AeroMetric's twin-engine Cessna 310, fixed wing aircraft equipped with a LiDAR system. The LiDAR system includes a differential GPS unit and inertial measurement system to provide superior positional accuracy.
Acquisition parameters:
1. Flight Height - 2500 meters above mean terrain
2. Swath Width - 34 degrees
3. Sidelap - 30%
4. Nominal Post Spacing - 1.5 meters
GPS and IMU processing parameters:
1. Maximum baseline length - Not greater than 40 kilometers.
2. Number of base stations during LiDAR collection - A minimum of 1.
3. Maximum positional RMS of trajectory during LiDAR collection - 0.05 meters
4. IMU processing monitored for consistency and smoothness - Yes.
Point Cloud Processing:
1. Horizontal Datum - NAD83(NSRS2007)
2. Horizontal Coordinates - Universal Transverse Mercator, Zone 14, in meters.
3. Vertical Datum - NAVD88
4. Geoid Model used to reduce satellite derived elevations to orthometric heights - NGS Geoid09.
LiDAR Processing:
1. Point Cloud data is imported via TerraScan in a Microstation V8 (V) CAD environment on a specified 1500 meter by 1500 meter tiling scheme.
2. Analyze the data for overall completeness and consistency. This is to ensure that there are no voids or anomalies in the data collection.
3. Inspect for calibration errors in the dataset using the TerraMatch software. This is accomplished by sampling the data collected across all flight lines and classify the individual lines to ground. The software will use the ground-classified points by flightline to compute corrections (Heading, Pitch, Roll, and Scale).
4. Orientation corrections (i.e. Calibration corrections) are applied (if needed) to the entire dataset.
5. Automatic ground classification is performed using algorithms with customized parameters to best fit the project area. Several areas of varying relief and planimetric features were inspected to verify the final ground surface.
6. AeroMetric, Inc. provided Quality Assurance and Quality Control (QA/QC) data for this project. AeroMetric captured QA/QC points in 'open terrain' land cover category that were used to test the accuracy of the LiDAR ground surface. TerraScan's Output Control Report (OCR) was used to compare the QA/QC data to the LiDAR data. This routine searches the LiDAR dataset by X and Y coordinate, finds the closest LiDAR point and compares the vertical (Z) values to the known data collected in the field. Based on the QA/QC data, a bias adjustment was determined, and the results were applied (if necessary) to the LiDAR data. A final OCR was performed with a resulting RMSE of 0.088 meters for the project.
7. Each tile is reviewed for accuracy and consistency of the macro ground classification.
8. Once the automatic processing and the testing of LiDAR is complete, AeroMetric meticulously reviews the generated bare-earth surface data to ensure that proper classification was achieved as part of a Quality Control process.
9. Final deliverables are generated and output to a client specified 1500 meters by 1500 meters tiling scheme.
2011-09-09T00:00:00
2
The NOAA Office for Coastal Management (OCM) downloaded topographic files (point clouds) in LAZ format from an USGS ftp site. The data was received in UTM Zone 14 North (in meters) and vertical coordinates were referenced to NAVD88 in meters using the Geoid09 model. OCM performed the following processing for data storage and Digital Coast provisioning purposes:
1. The All-Return LAZ files were checked for erroneous outliers removed.
2. The LAZ files were converted from a UTM coordinates to Geographic Coordinates (decimal degrees), then converted to ellipsoidal vertical units in meters with respect to the Geoid09.
3. Overlapping tiles (42) exist on the county boundary between Hidalgo and Willacy counties. These were decidedly left as is in order to extend past county boundaries for individual county requests. These are duplicate points between projects as they are the same acquired lidar points.
2015-12-20T00:00:00
gov.noaa.nmfs.inport:50048
Anne Ball
2017-11-15T15:23:58
Rebecca Mataosky
2022-08-15T15:37:12
2022-03-16
OCM Partners
OCMP
1002
Public
No
2022-03-16
1 Year
2023-03-16