2017 USGS Lidar: Upper Delta Plain, LA
Data Set (DS) | OCM Partners (OCMP)GUID: gov.noaa.nmfs.inport:52981 | Updated: October 17, 2023 | Published / External
Summary
Short Citation
OCM Partners, 2025: 2017 USGS Lidar: Upper Delta Plain, LA, https://www.fisheries.noaa.gov/inport/item/52981.
Full Citation Examples
Product: These lidar data are processed Classified LAS 1.4 files, formatted to 4802 individual 1500 m x 1500 m tiles; used to create intensity images, 3D breaklines and hydro-flattened DEMs as necessary.
Geographic Extent: Upper Delta Plain, Louisiana, covering approximately 3843 square miles.
Dataset Description: This Upper Delta Plain QL2 Lidar project called for the planning, acquisition, processing, and derivative products of lidar data to be collected at an aggregate nominal pulse spacing (ANPS) of 0.7 meters (2ppsm). Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.2. The data was developed based on a horizontal projection/datum of NAD83 (2011), Universal Transverse Mercator (zone 15 N), meters and vertical datum of NAVD88 (GEOID12B), meters. Lidar data was delivered as flightline-extent unclassified LAS swaths, as processed Classified LAS 1.4 files, formatted to 4802 individual 1500 m x 1500 m tiles, as tiled Intensity Imagery, as tiled bare earth DEMs, and as tiled digital surface models; all tiled to the same 1500 m x 1500 m schema.
Ground Conditions: Lidar was collected in early 2017, while no snow was on the ground and rivers were at or below normal levels. In order to post process the lidar data to meet task order specifications and meet ASPRS vertical accuracy guidelines, Terrasurv, Inc. established a total of 63 ground control points that were used to calibrate the lidar to known ground locations established throughout the Upper Delta Plain, Louisiana project area. An additional 179 independent accuracy checkpoints, 101 Bare Ground/Low Grass landcovers (101 NVA points), 67 in Tall Weeds/Brush categories, and 11 in Woods category (78 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data.
The NOAA Office for Coastal Management (OCM) downloaded 4802 LA_UpperDeltaPlain_2017 laz files from this USGS site: ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/USGS_LPC_LA_UpperDeltaPlain_2017_LAS_2018/ and processed the data to the Data Access Viewer (DAV) and https. One file was determined to be empty and verified by USGS. Number of laz files processed was 4801. Noted some Class 3 (low vegetation) points in water body areas.
In addition to these lidar point data, the bare earth Digital Elevation Models (DEM) created from the lidar point data are also available. These data are available for custom download at the link provided in the URL section of this metadata record.
Hydro breaklines are also available. These data are available for download at the link provided in the URL section of this metadata record. Please note that these products have not been reviewed by the NOAA Office for Coastal Management (OCM) and any conclusions drawn from the analysis of this information are not the responsibility of NOAA or OCM.
Distribution Information
-
Create custom data files by choosing data area, product type, map projection, file format, datum, etc. A new metadata will be produced to reflect your request using this record as a base.
-
LAS/LAZ - LASer
Bulk download of data files in LAZ format, geographic coordinates, orthometric heights. Note that the vertical datum (hence elevations) of the files here are different than described in this document.
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
COASTAL ELEVATION, elevation, TERRAIN 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
https://coast.noaa.gov
Metadata Contact
NOAA Office for Coastal Management (NOAA/OCM)
coastal.info@noaa.gov
(843) 740-1202
https://coast.noaa.gov
Extents
-91.53485° W,
-89.51626° E,
30.50229° N,
29.457351° S
2017-01-23
2017-01-26
2017-01-27
2017-01-28
2017-01-30
2017-01-31
2017-02-15
2017-02-22
2017-02-25
2017-03-02
2017-03-03
2017-03-14
2017-03-15
2017-03-16
2017-03-20
2017-04-24
Item Identification
Title: | 2017 USGS Lidar: Upper Delta Plain, LA |
---|---|
Short Name: | la2017_up_delta_pln_m8564_metadata |
Status: | Completed |
Publication Date: | 2018-01-25 |
Abstract: |
Product: These lidar data are processed Classified LAS 1.4 files, formatted to 4802 individual 1500 m x 1500 m tiles; used to create intensity images, 3D breaklines and hydro-flattened DEMs as necessary. Geographic Extent: Upper Delta Plain, Louisiana, covering approximately 3843 square miles. Dataset Description: This Upper Delta Plain QL2 Lidar project called for the planning, acquisition, processing, and derivative products of lidar data to be collected at an aggregate nominal pulse spacing (ANPS) of 0.7 meters (2ppsm). Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.2. The data was developed based on a horizontal projection/datum of NAD83 (2011), Universal Transverse Mercator (zone 15 N), meters and vertical datum of NAVD88 (GEOID12B), meters. Lidar data was delivered as flightline-extent unclassified LAS swaths, as processed Classified LAS 1.4 files, formatted to 4802 individual 1500 m x 1500 m tiles, as tiled Intensity Imagery, as tiled bare earth DEMs, and as tiled digital surface models; all tiled to the same 1500 m x 1500 m schema. Ground Conditions: Lidar was collected in early 2017, while no snow was on the ground and rivers were at or below normal levels. In order to post process the lidar data to meet task order specifications and meet ASPRS vertical accuracy guidelines, Terrasurv, Inc. established a total of 63 ground control points that were used to calibrate the lidar to known ground locations established throughout the Upper Delta Plain, Louisiana project area. An additional 179 independent accuracy checkpoints, 101 Bare Ground/Low Grass landcovers (101 NVA points), 67 in Tall Weeds/Brush categories, and 11 in Woods category (78 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data. The NOAA Office for Coastal Management (OCM) downloaded 4802 LA_UpperDeltaPlain_2017 laz files from this USGS site: ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/USGS_LPC_LA_UpperDeltaPlain_2017_LAS_2018/ and processed the data to the Data Access Viewer (DAV) and https. One file was determined to be empty and verified by USGS. Number of laz files processed was 4801. Noted some Class 3 (low vegetation) points in water body areas. In addition to these lidar point data, the bare earth Digital Elevation Models (DEM) created from the lidar point data are also available. These data are available for custom download at the link provided in the URL section of this metadata record. Hydro breaklines are also available. These data are available for download at the link provided in the URL section of this metadata record. Please note that these products have not been reviewed by the NOAA Office for Coastal Management (OCM) and any conclusions drawn from the analysis of this information are not the responsibility of NOAA or OCM. |
Purpose: |
The new elevation information derived from the lidar data will provide a more accurate elevation surface for CoNED development, including landscape modeling and projections, while providing needed elevation monitoring information for coastal restoration project planning and implementation. |
Supplemental Information: |
USGS Contract No. G11PC00014 CONTRACTOR: Fugro EarthData, Inc. SUBCONTRACTOR: Terrasurv, Inc. Ground control and checkpoints collected by Terrasurv, Inc. All processing was completed by the prime contractor. The following are the USGS lidar fields in JSON: {
"ldrinfo" : {
"ldrspec" : "USGS-NGP Base Lidar Specification v1.2", "ldrsens" : "Riegl LMS-Q680i; Riegl LMS-Q780", "ldrmaxnr" : "7; 7", "ldrnps" : "0.7; 0.7", "ldrdens" : "2; 2", "ldranps" : "0.7; 0.7", "ldradens" : "2; 2", "ldrfltht" : "1000; 1341", "ldrfltsp" : "134; 137", "ldrscana" : "60; 60", "ldrscanr" : "100; 110", "ldrpulsr" : "240; 365", "ldrpulsd" : "3; 3", "ldrpulsw" : "0.8994; 0.8994", "ldrwavel" : "1550; 1064", "ldrmpia" : "1; 1", "ldrbmdiv" : "≤ 0.5; ≤ 0.25", "ldrswatw" : "1200; 1500", "ldrswato" : "29; 28", "ldrcrs" : "NAD 1983 2011 UTM Zone 15N Meters", "ldrgeoid" : "National Geodetic Survey (NGS) GEOID12B" }, "ldraccur" : {
"ldrchacc" : "0.26; 0.22", "rawnva" : "0.097", "rawnvan" : "101", "clsnva" : "0.099", "clsnvan" : "101", "clsvva" : "0.276", "clsvvan" : "72" }, "lasinfo" : {
"lasver" : "1.4", "lasprf" : "6", "laswheld" : "There were no withheld points identified in this project. All points were used in the classification.", "lasolap" : "Swath "overage" points were identified in these files using the standard LAS overlap bit.", "lasintr" : "16 bit", "lasclass" : {
"clascode" : "1", "clasitem" : "Processed, but unclassified" }, "lasclass" : {
"clascode" : "2", "clasitem" : "Bare-earth ground" }, "lasclass" : {
"clascode" : "3", "clasitem" : "Low Vegetation (3 meters or less)" }, "lasclass" : {
"clascode" : "7", "clasitem" : "Low Noise" }, "lasclass" : {
"clascode" : "9", "clasitem" : "Water" }, "lasclass" : {
"clascode" : "10", "clasitem" : "Ignored Ground" }, "lasclass" : {
"clascode" : "17", "clasitem" : "Bridge Decks" }, "lasclass" : {
"clascode" : "18", "clasitem" : "High Noise" } }} |
Keywords
Theme Keywords
Thesaurus | Keyword |
---|---|
Global Change Master Directory (GCMD) Science Keywords |
EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION
|
Global Change Master Directory (GCMD) Science Keywords |
EARTH SCIENCE > OCEANS > COASTAL PROCESSES > COASTAL ELEVATION
|
ISO 19115 Topic Category |
elevation
|
UNCONTROLLED | |
None | DEM |
None | digital elevation model |
None | Elevation Data |
None | erosion |
None | LAS Point Cloud |
None | laser |
None | Lidar |
None | Model |
None | Remote Sensing |
None | Topography |
Spatial Keywords
Thesaurus | Keyword |
---|---|
Global Change Master Directory (GCMD) Location Keywords |
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > LOUISIANA
|
Global Change Master Directory (GCMD) Location Keywords |
VERTICAL LOCATION > LAND SURFACE
|
UNCONTROLLED | |
Geographic Names Information System | Upper Delta Plain |
None | U.S. Coastline |
Instrument Keywords
Thesaurus | Keyword |
---|---|
Global Change Master Directory (GCMD) Instrument Keywords |
LIDAR > Light Detection and Ranging
|
Platform Keywords
Thesaurus | Keyword |
---|---|
Global Change Master Directory (GCMD) Platform Keywords |
Airplane > Airplane
|
Physical Location
Organization: | Office for Coastal Management |
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City: | Charleston |
State/Province: | SC |
Data Set Information
Data Set Scope Code: | Data Set |
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Data Set Type: | Elevation |
Maintenance Frequency: | None Planned |
Data Presentation Form: | Point Cloud (Digital) |
Distribution Liability: |
Users should not use these data for critical applications without a full awareness of its limitations. Any conclusions drawn from the analysis of this information are not the responsibility of the U.S. Geological Survey, the Coastal Protection and Restoration Authority of Louisiana (CPRA), NOAA, the Office for Coastal Management or its partners. |
Data Set Credit: | Acknowledgement of the U.S. Geological Survey and CPRA would be appreciated for products derived from these data. |
Support Roles
Data Steward
Date Effective From: | 2018 |
---|---|
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: | 2018 |
---|---|
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: | 2018 |
---|---|
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: | 2018 |
---|---|
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: | Ground Condition |
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Extent Group 1
Extent Group 1 / Geographic Area 1
W° Bound: | -91.53485 | |
---|---|---|
E° Bound: | -89.51626 | |
N° Bound: | 30.50229 | |
S° Bound: | 29.457351 |
Extent Group 1 / Time Frame 1
Time Frame Type: | Discrete |
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Start: | 2017-01-23 |
Extent Group 1 / Time Frame 2
Time Frame Type: | Discrete |
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Start: | 2017-01-26 |
Extent Group 1 / Time Frame 3
Time Frame Type: | Discrete |
---|---|
Start: | 2017-01-27 |
Extent Group 1 / Time Frame 4
Time Frame Type: | Discrete |
---|---|
Start: | 2017-01-28 |
Extent Group 1 / Time Frame 5
Time Frame Type: | Discrete |
---|---|
Start: | 2017-01-30 |
Extent Group 1 / Time Frame 6
Time Frame Type: | Discrete |
---|---|
Start: | 2017-01-31 |
Extent Group 1 / Time Frame 7
Time Frame Type: | Discrete |
---|---|
Start: | 2017-02-15 |
Extent Group 1 / Time Frame 8
Time Frame Type: | Discrete |
---|---|
Start: | 2017-02-22 |
Extent Group 1 / Time Frame 9
Time Frame Type: | Discrete |
---|---|
Start: | 2017-02-25 |
Extent Group 1 / Time Frame 10
Time Frame Type: | Discrete |
---|---|
Start: | 2017-03-02 |
Extent Group 1 / Time Frame 11
Time Frame Type: | Discrete |
---|---|
Start: | 2017-03-03 |
Extent Group 1 / Time Frame 12
Time Frame Type: | Discrete |
---|---|
Start: | 2017-03-14 |
Extent Group 1 / Time Frame 13
Time Frame Type: | Discrete |
---|---|
Start: | 2017-03-15 |
Extent Group 1 / Time Frame 14
Time Frame Type: | Discrete |
---|---|
Start: | 2017-03-16 |
Extent Group 1 / Time Frame 15
Time Frame Type: | Discrete |
---|---|
Start: | 2017-03-20 |
Extent Group 1 / Time Frame 16
Time Frame Type: | Discrete |
---|---|
Start: | 2017-04-24 |
Access Information
Security Class: | Unclassified |
---|---|
Data Access Procedure: |
Data is available online for bulk and custom downloads. |
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
Start Date: | 2018 |
---|---|
End Date: | Present |
Download URL: | https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=8564 |
Distributor: | |
File Name: | Customized Download |
Description: |
Create custom data files by choosing data area, product type, map projection, file format, datum, etc. A new metadata will be produced to reflect your request using this record as a base. |
Compression: | Zip |
Distribution 2
Start Date: | 2018 |
---|---|
End Date: | Present |
Download URL: | https://coast.noaa.gov/htdata/lidar2_z/geoid18/data/8564 |
Distributor: | |
File Name: | Bulk Download |
Description: |
Bulk download of data files in LAZ format, geographic coordinates, orthometric heights. Note that the vertical datum (hence elevations) of the files here are different than described in this document. |
File Type (Deprecated): | LAZ |
Distribution Format: | LAS/LAZ - LASer |
Compression: | Zip |
URLs
URL 1
URL: | https://coast.noaa.gov/ |
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Name: | NOAA's Office for Coastal Management (OCM) website |
URL Type: |
Online Resource
|
File Resource Format: | HTML |
Description: |
Information on the NOAA Office for Coastal Management (OCM) |
URL 2
URL: | https://coast.noaa.gov/dataviewer/ |
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Name: | NOAA's Office for Coastal Management (OCM) Data Access Viewer (DAV) |
URL Type: |
Online Resource
|
File Resource Format: | HTML |
Description: |
The Data Access Viewer (DAV) allows a user to search for and download elevation, imagery, and land cover data for the coastal U.S. and its territories. The data, hosted by the NOAA Office for Coastal Management, can be customized and requested for free download through a checkout interface. An email provides a link to the customized data, while the original data set is available through a link within the viewer. |
URL 3
URL: | https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/8564/supplemental/la2017_usgs_up_del_pln_m8564.kmz |
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Name: | Browse graphic |
URL Type: |
Browse Graphic
|
File Resource Format: | KML |
Description: |
This graphic displays the footprint for this lidar data set. |
URL 4
URL: | https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/8564/supplemental/UpperDeltaPlainLA_Lidar_Survey_Report.pdf |
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Name: | Dataset survey report |
URL Type: |
Online Resource
|
File Resource Format: | |
Description: |
Link to survey report. |
URL 5
URL: | https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/8564/breaklines/ |
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URL Type: |
Online Resource
|
Description: |
Link to the breaklines. |
URL 6
URL: | https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/8564/supplemental/UpperDeltaPlainLA_Lidar_Collection_Report.pdf |
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Name: | Data set collection report |
URL Type: |
Online Resource
|
Description: |
Link to the collection report. |
URL 7
URL: | https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/8564/supplemental/UpperDeltaPlainLA_Lidar_Project_Report.pdf |
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Name: | Data set project report |
URL Type: |
Online Resource
|
Description: |
Link to the project report. |
URL 8
URL: | https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=8568 |
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URL Type: |
Online Resource
|
Description: |
Link to custom download, from the Data Access Viewer (DAV), the raster Digital Elevation Model (DEM) data that were created from this lidar data set. |
Technical Environment
Description: |
MicroStation CONNECT 10.00.00.25; TerraScan 017.004 and 016.013; TerraModeler 016.001 and 016.006; Lasedit 1.35.07; GeoCue 2014.1.21.5; Fugro proprietary software; Windows 7 64-bit Operating System \\server\directory path\*.las 1.26 TB |
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Data Quality
Horizontal Positional Accuracy: |
The horizontal errors in lidar data are largely a function of the Global Navigation Satellite System (GNSS) positional errors, the Inertial Measurement Unit (IMU) angular errors, and the flying altitude. If the accuracy of the GNSS/IMU solution is known for the specific POS system, using the flying altitude of the project the expected horizontal errors in the LiDAR data can be estimated. Following the formula in the ASPRS Positional Accuracy Standards for Digital Geospatial Data (Edition 1, Version 1.0. - November, 2014), using the specifications of the POS system used and 1000 m flying altitude above ground for the Riegl LMS-Q680i, the estimated horizontal accuracy is RMSEr = 0.26 m; using the specifications of the POS system used and 1341 m flying altitude above ground for the Riegl LMS-Q780, the estimated horizontal accuracy is RMSEr = 0.22 m. |
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Vertical Positional Accuracy: |
The Non-Vegetated Vertical Accuracy (NVA) of the Lidar Point Cloud data was calculated against TINs derived from the final calibrated and controlled swath data. The required accuracy (ACCZ) is: 19.6 cm at a 95% confidence level, derived according to NSSDA, i.e., based on RMSEZ of 10 cm in the “open terrain” and/or “Urban” land cover categories. This is a required accuracy. The raw swath point cloud data met the required accuracy levels before point cloud classification and derivative product generation. NVA RMSEz = 4.9 cm NVA at 95 percent confidence level = 9.7 cm |
Completeness Report: |
The Classified Point Cloud data files include all data points collected except the ones from Cross ties and Calibration lines. The points that have been removed or excluded are the points fall outside the project delivery boundary. Points are classified. A visual qualitative assessment was performed to ensure data completeness. No void areas or missing data exist. The classified point cloud is of good quality and data passes Vertical Accuracy requirements. |
Conceptual Consistency: |
Compliance with the accuracy standard was ensured by the collection of ground control and the establishment of GPS base stations in the project area. The following checks were performed: 1) The lidar data accuracy was validated by performing a full boresight adjustment and then checking it against the ground control prior to generating a digital terrain model (DTM) or other products. 2) Lidar elevation data was validated through an inspection of edge matching and visual inspection for quality (artifact removal). The following software was used for the validation: 1) RiProcess 1.8.3, RiWorld 5.0.2, RiAnalyze 6.2, RiServer 1.99.5; and 2) Fugro proprietary software; 20170515. |
Lineage
Sources
Upper Delta Plain, Louisiana Lidar Aerial Acquisition
Contact Name: | Fugro |
---|---|
Publish Date: | 2017-04-26 |
Source Contribution: |
Fugro collected Riegl-derived lidar over the Upper Delta Plain, Louisiana AOI with 0.7 meters ANPS. Data was collected when environmental conditions meet the criteria specified. To be specific, the following conditions existed prior to launch of the aircraft: 1) Water levels for either Grand Isle, LA or Shell Beach, LA were below -0.10 meters (mean sea level), for flight lines that were considered tidal, 2) Passage of a moderate to strong high-pressure system generating northerly winds in excess of 5 knots, 3) Cloud and fog-free between the aircraft and ground, 4) Snow free, 5) No unusual flooding or inundation, and 6) Leaf off. The collection for the Upper Delta Plain, Louisiana AOI was accomplished on January 23, 26, 27, 28, 30, and 31; February 15, 22, and 25; March 2, 3, 14, 15, 16, and 20; and April 24, 2017. The collection was performed using Riegl LMS-Q680i and Riegl LMS-Q780 lidar systems, serial numbers 165, 961, and 216. |
Upper Delta Plain, Louisiana Lidar Report of Survey
Contact Name: | Terrasurv, Inc. |
---|---|
Publish Date: | 2017-04-06 |
Extent Type: | Range |
Extent Start Date/Time: | 2017-02-20 |
Extent End Date/Time: | 2017-03-22 |
Source Contribution: |
Under Fugro’s direction, all surveying activities were performed by Fugro's approved ID/IQ subcontractor Terrasurv, Inc. A total of 63 ground control points to support the lidar collection, along with 101 NVA and 78 VVA checkpoints were collected. The National Spatial Reference System (NSRS) was used to provide control for the network. A Virtual Reference System (VRS) was used to survey each of the lidar control points. GULFNet is a network of Continuously Operating Reference Stations (CORS) network operated by the Louisiana Spatial Reference Center which is tightly aligned with the CORS of the National Spatial Reference System (NSRS). Using this methodology and VRS network was crucial to being able to obtain accurate heights due to known subsidence issues with the passive (i.e. ground monumented stations) NSRS marks in the area. Many of the GULFNet stations are also part of the National CORS Network. The horizontal datum was the North American Datum of 1983 – NAD83 (2011), epoch 2010.0. The vertical datum was the North American Vertical Datum of 1988 (NAVD88), realized with GEOID12B. |
Process Steps
Process Step 1
Description: |
Flight status was communicated during data collection. All acquired lidar data went through a preliminary review to assure that complete coverage had been obtained and that there were no gaps between flight lines before the flight crew left the project site. Once back in the office, the data was run through a complete iteration of processing to ensure that it is complete, uncorrupted, and that the entire project area has been covered without gaps between flight lines. There are essentially three steps to this processing: 1) GPS/IMU Processing - Airborne GPS and IMU data was processed using the airport GPS base station data. The following GPS base stations were utilized: Fugro (016), CORS (MOON), and CORS (SJHS). 2) Raw Lidar Data Processing - Technicians processed the raw data to LAS format flight lines with full resolution output before performing QC. A starting configuration file is used in this process, which contains the latest calibration parameters for the sensor. The technicians also generated flight line trajectories for each of the flight lines during this process. 3) Verification of Coverage and Data Quality - Technicians checked trajectory files to ensure completeness of acquisition for the flight lines, calibration lines, and cross flight lines. The intensity images were generated for the entire lift at the required 0.7 meter ANPS. Visual checks of the intensity images against the project boundary were performed to ensure full coverage to the 100 meter buffer beyond the project boundary. The intensity histogram was analyzed to ensure the quality of the intensity values. The technician also thoroughly reviewed the data for any gaps in project area. The technician generated a sample TIN surface to ensure no anomalies were present in the data. Turbulence was inspected for each flight line; if any adverse quality issues were discovered, the flight line was rejected and re-flown. The technician also evaluated the achieved post spacing against project specified 0.7 meter ANPS as well as making sure there is no clustering in point distribution. |
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Process Date/Time: | 2017-04-26 00:00:00 |
Process Step 2
Description: |
The boresight for each lift was done individually as the solution may change slightly from lift to lift. The following steps describe the Raw Data Processing and Boresight process: 1) Technicians processed the raw data to LAS format flight lines using the final GPS/IMU solution. This LAS data set was used as source data for boresight. 2) Technicians first used Fugro proprietary and commercial software to calculate initial boresight adjustment angles based on sample areas within the lift. These areas cover calibration flight lines collected in the lift, cross tie and production flight lines. These areas are well distributed in the lift coverage and cover multiple terrain types that are necessary for boresight angle calculation. The technician then analyzed the results and made any necessary additional adjustment until it is acceptable for the selected areas. 3) Once the boresight angle calculation was completed for the selected areas, the adjusted settings were applied to all of the flight lines of the lift and checked for consistency. The technicians utilized commercial and proprietary software packages to analyze the matching between flight line overlaps for the entire lift and adjusted as necessary until the results met the project specifications. 4) Once all lifts were completed with individual boresight adjustment, the technicians checked and corrected the vertical misalignment of all flight lines and also the matching between data and ground truth. The relative accuracy was ≤ 6 cm within individual swaths (smooth surface repeatability) and ≤ 8 cm RMSD within swath overlap (between adjacent swaths) with a maximum difference of ± 16 cm. 5) The technicians ran a final vertical accuracy check of the boresighted flight lines against the surveyed check points after the z correction to ensure the requirement of RMSEZ (non-vegetated) ≤ 10 cm, NVA ≤ 19.6 cm 95% Confidence Level was met. |
---|---|
Process Date/Time: | 2017-05-15 00:00:00 |
Process Step 3
Description: |
Once boresighting was complete for the project, the project was first set up for automatic classification. The lidar data was cut to production tiles. The low noise points, high noise points and ground points were classified automatically in this process. Fugro utilized commercial software, as well as proprietary, in-house developed software for automatic filtering. The parameters used in the process were customized for each terrain type to obtain optimum results. Once the automated filtering was completed, the files were run through a visual inspection to ensure that the filtering was not too aggressive or not aggressive enough. In cases where the filtering was too aggressive and important terrain were filtered out, the data was either run through a different filter within local area or was corrected during the manual filtering process. Bridge deck points were classified as well during the interactive editing process. Interactive editing was completed in visualization software that provides manual and automatic point classification tools. Fugro utilized commercial and proprietary software for this process. All manually inspected tiles went through a peer review to ensure proper editing and consistency. After the manual editing and peer review, all tiles went through another final automated classification routine. This process ensures only the required classifications are used in the final product (all points classified into any temporary classes during manual editing will be re-classified into the project specified classifications). Once manual inspection, QC and final autofilter is complete for the lidar tiles, the LAS data was packaged to the project specified tiling scheme, clipped to project boundary including the 100 meter buffer and formatted to LAS v1.4. It was also re-projected to UTM Zone 15 north; NAD83 (2011), meters; NAVD88 (GEOID12B), meters. The file header was formatted to meet the project specification with File Source ID assigned. This Classified Point Cloud product was used for the generation of derived products. This product was delivered in fully compliant LAS v1.4, Point Record Format 6 with Adjusted Standard GPS Time at a precision sufficient to allow unique timestamps for each pulse. Correct and properly formatted georeference information as Open Geospatial Consortium (OGC) well known text (WKT) was assigned in all LAS file headers. Each tile has unique File Source ID assigned. The Point Source ID matches to the flight line ID in the flight trajectory files. Intensity values are included for each point, normalized to 16-bit. The following classifications are included: Class 1 – Processed, but unclassified; Class 2 – Bare earth ground; Class 3 – Low Vegetation (3 meters or less); Class 7 – Low Noise; Class 9 – Water; Class 10 – Ignored Ground; Class 17 – Bridge Decks; and Class 18 – High Noise. The classified point cloud data was delivered in tiles without overlap using the project tiling scheme. |
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Process Date/Time: | 2018-01-25 00:00:00 |
Process Step 4
Description: |
The NOAA Office for Coastal Management (OCM) downloaded 4802 LA_UpperDeltaPlain_2017 laz files from this USGS site: ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/USGS_LPC_LA_UpperDeltaPlain_2017_LAS_2018/. One file was determined to be empty and verified by USGS. Number of laz files processed was 4801. Noted some Class 3 (low vegetation) points in water body areas. The data were in UTM Zone 15 North coordinates and NAVD88 (Geoid12B) elevations in meters. The data were classified as: 1 - Unclassified, 2 - Ground, 3 - Low vegetation (less than or equal to 3 meters), 7 - Low Noise, 9 - Water, 10 - Ignored Ground, 17 - Bridge Decks, 18 - High Noise. OCM processed all classifications of points to the Digital Coast Data Access Viewer (DAV). Classes available on the DAV are: 1, 2, 3, 7, 9, 10, 17, 18. OCM performed the following processing on the data for Digital Coast storage and provisioning purposes: 1. The LAStools software scripts lasinfo and lasvalidate were run on the laz files to check for errors. 2. An internal OCM script was run to check the number of points by classification and by flight ID and the gps and intensity ranges. 3. Internal OCM scripts were run on the laz files to convert from orthometric (NAVD88) elevations to ellipsoid elevations using the Geoid 12B model, to convert from NAD83 2011 UTM Zone 15 North coordinates in meters to geographic coordinates, to assign the geokeys, to sort the data by gps time and zip the data to database and to http. |
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Process Date/Time: | 2018-07-10 00:00:00 |
Process Contact: | Office for Coastal Management (OCM) |
Catalog Details
Catalog Item ID: | 52981 |
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GUID: | gov.noaa.nmfs.inport:52981 |
Metadata Record Created By: | Rebecca Mataosky |
Metadata Record Created: | 2018-07-03 11:43+0000 |
Metadata Record Last Modified By: | SysAdmin InPortAdmin |
Metadata Record Last Modified: | 2023-10-17 16:12+0000 |
Metadata Record Published: | 2018-08-23 |
Owner Org: | OCMP |
Metadata Publication Status: | Published Externally |
Do Not Publish?: | N |
Metadata Last Review Date: | 2018-08-23 |
Metadata Review Frequency: | 1 Year |
Metadata Next Review Date: | 2019-08-23 |