gov.noaa.nmfs.inport:56114
eng
UTF8
dataset
Elevation
National Geodetic Survey
resourceProvider
NOAA Office for Coastal Management
(843) 740-1202
2234 South Hobson Ave
Charleston
SC
29405-2413
coastal.info@noaa.gov
https://coast.noaa.gov
WWW:LINK-1.0-http--link
NOAA Office for Coastal Management Website
NOAA Office for Coastal Management Home Page
information
pointOfContact
2024-02-29T00:00:00
ISO 19115-2 Geographic Information - Metadata Part 2 Extensions for imagery and gridded data
ISO 19115-2:2009(E)
EPSG::6319
2018 NOAA National Geodetic Survey Topobathy Lidar: Potomac River, Chesapeake Bay
2019-05
publication
NOAA/NMFS/EDM
56114
https://www.fisheries.noaa.gov/inport/item/56114
WWW:LINK-1.0-http--link
Full Metadata Record
View the complete metadata record on InPort for more information about this dataset.
information
https://coast.noaa.gov/dataviewer
WWW:LINK-1.0-http--link
Citation URL
Data Access Viewer for discovering coastal imagery, land cover, and elevation data
download
https://coast.noaa.gov
WWW:LINK-1.0-http--link
Citation URL
Web page for the NOAA Office for Coastal Management
download
https://coast.noaa.gov/dataregistry
WWW:LINK-1.0-http--link
Citation URL
Web page to the Digital Coast for finding coastal data
download
These data were collected by Quantum Spatial, Inc. (QSI) for the National Oceanic and Atmospheric Administration (NOAA), National Geodetic Survey (NGS), Remote Sensing Division (RSD), Coastal Mapping Program (CMP) using a Riegl VQ880G system. The delivery 02 lidar data were acquired from 20180215 - 20180417 in five missions. The dataset includes topobathy data in a LAS 1.2 format file with the following classification: unclassified (1), ground (2), noise (7), overlap default (19), overlap ground (20), overlap water column (21), water column (25), bathymetric bottom or submerged topography (26), submerged feature (29), submerged aquatic vegetation (30), and temporal bathy bottom (31) in accordance with project specifications. The contracted project consists of approximately 309.125 square miles (197,840 acres) of the states of Virginia and Maryland covering the confluence of the Potomac River and the Chesapeake Bay. To ensure complete coverage and adequate point densities around survey area boundaries, the Area of Interest (AOI) was buffered by 100m. The full project area including buffered area is approximately 478.151 square miles (306,017 acres). LAS files were compiled by 500 m x 500 m tiles.
This lidar data (and digital camera imagery collected under the same task order) was required by National Oceanic and Atmospheric Administration (NOAA), the National Geodetic Survey (NGS), Remote Sensing Division Coastal Mapping Program (CMP) to enable accurate and consistent measurement of the national shoreline. The CMP works to provide a regularly updated and consistent national shoreline to define America's marine territorial limits and manage coastal resources.
NOAA National Geodetic Survey (NGS).
completed
NOAA Office for Coastal Management
(843) 740-1202
2234 South Hobson Ave
Charleston
SC
29405-2413
coastal.info@noaa.gov
https://coast.noaa.gov
WWW:LINK-1.0-http--link
NOAA Office for Coastal Management Website
NOAA Office for Coastal Management Home Page
information
pointOfContact
NOAA Office for Coastal Management
(843) 740-1202
2234 South Hobson Ave
Charleston
SC
29405-2413
coastal.info@noaa.gov
https://coast.noaa.gov
WWW:LINK-1.0-http--link
NOAA Office for Coastal Management Website
NOAA Office for Coastal Management Home Page
information
custodian
notPlanned
EARTH SCIENCE > OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > BATHYMETRY
EARTH SCIENCE > OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > SEAFLOOR TOPOGRAPHY
EARTH SCIENCE > OCEANS > COASTAL PROCESSES > COASTAL ELEVATION
theme
Global Change Master Directory (GCMD) Science Keywords
17.0
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > MARYLAND
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > VIRGINIA
place
Global Change Master Directory (GCMD) Location Keywords
17.0
20180215
20180417
temporal
Continent > North America > United States of America > Chesapeake Bay
place
DOC/NOAA/NOS/NGS > National Geodetic Survey, National Ocean Service, NOAA, U.S. Department of Commerce
dataCentre
Global Change Master Directory (GCMD) Data Center Keywords
2017-04-24
publication
8.5
NGS Lidar
project
InPort
otherRestrictions
Cite As: National Geodetic Survey, [Date of Access]: 2018 NOAA National Geodetic Survey Topobathy Lidar: Potomac River, Chesapeake Bay [Data Date Range], https://www.fisheries.noaa.gov/inport/item/56114.
NOAA provides no warranty, nor accepts any liability occurring from any incomplete, incorrect, or misleading data, or from any incorrect, incomplete, or misleading use of the data. It is the responsibility of the user to determine whether or not the data is suitable for the intended purpose.
otherRestrictions
Access Constraints: None
otherRestrictions
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.
otherRestrictions
Distribution Liability: Any conclusions drawn from the analysis of this information are not the responsibility of NOAA, the National Geodetic Survey, the Office for Coastal Management, or its partners.
unclassified
NOAA Data Management Plan (DMP)
NOAA/NMFS/EDM
56114
https://www.fisheries.noaa.gov/inportserve/waf/noaa/nos/ngs/dmp/pdf/56114.pdf
WWW:LINK-1.0-http--link
NOAA Data Management Plan (DMP)
NOAA Data Management Plan for this record on InPort.
information
crossReference
vector
eng; US
elevation
-76.791568
-76.176395
37.715495
38.332869
| Currentness: Ground Condition
2018-02-15
2018-04-17
The NOAA Chesapeake Bay Initial Award data includes all lidar returns. An automated grounding classification algorithm was used to determine bare earth and submerged topography point classification. The automated grounding was followed with manual editing. The full workflow used for this project is documented in the NOAA FY18 Chesapeake Bay Initial Award final report.
false
eng
false
Other
NOAA NGS Topobathy Lidar Class Scheme: Potomac River, Chesapeake Bay
2024-02-01
publication
ZIP
Zip
LAS/LAZ - LASer
Zip
KML/KMZ - Keyhole Markup Language
Zip
NOAA Office for Coastal Management
(843) 740-1202
2234 South Hobson Ave
Charleston
SC
29405-2413
coastal.info@noaa.gov
https://coast.noaa.gov
WWW:LINK-1.0-http--link
NOAA Office for Coastal Management Website
NOAA Office for Coastal Management Home Page
information
distributor
https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=8727
WWW:LINK-1.0-http--link
https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=8727
Link to custom download
download
https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/8727/index.html
WWW:LINK-1.0-http--link
https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/8727/index.html
Link to bulk LAZ files
download
https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/8727/supplemental/2018_ngs_topobathy_potomac_river_m8727.kmz
WWW:LINK-1.0-http--link
https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/8727/supplemental/2018_ngs_topobathy_potomac_river_m8727.kmz
KMZ displays the footprint for this lidar data set.
download
dataset
Vertical Positional Accuracy
Using NSSDA and FEMA methodology, the point cloud non-vegetated vertical accuracy (NVA) at the 95% confidence level (called Accuracyz) was computed by the formula RMSEz x 1.9600. The NOAA Chesapeake Bay Initial Award delivery 01 and delivery 02 dataset tested 0.048 m vertical accuracy at 95% confidence level against the unclassified Lidar point cloud in open terrain using 27 ground check points, based on RMSEz (0.024 m) x 1.9600.
Using NDEP and ASPRS methodology, vegetated vertical accuracy (VVA) was computed using the 95th percentile method. The NOAA Chesapeake Bay Initial Award delivery 01 and delivery 02 dataset tested 0.155 m vegetated vertical accuracy at 95th percentile against the derived bare earth DEM using 17 mixed landclass points.
Using NSSDA and FEMA methodology, bathymetric vertical accuracy at the 95% confidence level for submerged topography was computed by the formula RMSEz x 1.9600. The NOAA Chesapeake Bay Initial Award delivery 01 and delivery 02 dataset tested 0.070 m vertical accuracy at 95% confidence level against the classified points cloud using 727 submerged check points, based on RMSEz (0.036 m) x 1.9600. Submerged topography checkpoints usually occur in depths up to 1m.
Quantitation Limits
Absolute accuracy was assessed using both Non-Vegetated Vertical Accuracy (NVA) and Vegetated Vertical Accuracy (VVA) survey methods. Survey checkpoints were evenly distributed throughout the project area as feasible. NVA compares known ground check point data that were withheld from the calibration and post-processing of the LiDAR point cloud to the triangulated surface generated by the unclassified LiDAR point cloud as well as the derived gridded bare earth DEM. NVA is a measure of the accuracy of LiDAR point data in open areas with level slope (less than 20 degrees) where the LiDAR system has a high probability of measuring the ground surface and is evaluated at the 95% confidence interval (1.96*RMSE). In the Initial Award delivery 01 and delivery 02 areas, 27 survey checkpoints were used to assess the non-vegetated vertical accuracy. Project specifications require NVA meet 0.196 m accuracy at the 95% confidence interval. Ground check points located in land cover categories other than bare earth, urban, or submerged topography were used to compute the Vegetated Vertical Accuracy (VVA). QSI assessed four land cover categories: deciduous forest, mixed forest, and tall grass, and shrubland. In the Initial Award delivery 01 and delivery 02 areas, 17 survey checkpoints were used to assess the vegetated vertical accuracy. Project specifications require VVA meet 0.36 m based on the 95th percentile tested against the derived bare earth DEM. Submerged topography points were tested separately. In the Initial Award delivery 01 and delivery 02 areas, 727 survey checkpoints were used to assess the submerged topography accuracy. Submerged topography checkpoints usually occur in depths up to 1m. Project specifications require submerged topography to meet 0.490 m at the 95% confidence level based on RMSEz x 1.9600.
Data was acquired by Quantum Spatial (QSI) using a Riegl VQ-880G Topobathy LiDAR system. All delivered LiDAR data is referenced to:
Horizontal Datum-NAD83 (2011) epoch: 2010
Projection-UTM Zone 18N
Horizontal Units-meters
Vertical Datum-GRS 80 Ellipsoid
Vertical Units-meters
The dataset encompasses 5,974 500m x 500m tiles covering the states of Virginia and Maryland at the confluence of the Potomac River and the Chesapeake Bay. Green and NIR (for water surface model creation that is used during refraction of the green bathymetric data) LiDAR data were acquired with the Riegl sensor VQ-880G.
QSI reviewed all acquired flight lines to ensure complete coverage and positional accuracy of the laser points. QSI creates an initial product call Quick Look Coverage Maps. These Quick Look files are not fully processed data or final products. The collected LiDAR data is immediately processed in the field by QSI to a level that will allow QA\QC measures to determine if the sensor is functioning properly and assess the coverage of submerged topography. An initial SBET was created in POSPAC MMS 8.1 and used in RiProcess which applies pre-calibrated angular misalignment corrections of scanner position to extract the raw point cloud into geo-referenced LAS files. These files were inspected for sensor malfunctions and then passed through automated classification routines (TerraScan) to develop a rough topobathymetric ground model for an initial assessment of bathymetric coverage.
To correct the continuous onboard measurements of the aircraft position recorded throughout the missions, QSI concurrently conducted multiple static Global Navigation Satellite System (GNSS) ground surveys (1 Hz recording frequency) over established monuments located in or around the project area. After the airborne survey, the static GPS data were triangulated with nearby Continuously Operating Reference Stations (CORS) using the Online Positioning User Service (OPUS) for precise positioning. Multiple independent sessions over the same monument were processed to confirm antenna height measurements and to refine position accuracy. QSI then resolved kinematic corrections for aircraft position data using kinematic aircraft GPS and static ground GPS data. A final smoothed best estimate trajectory (SBET) was developed that blends post-processed aircraft position with attitude data. Sensor head position and attitude are calculated throughout the survey. The SBET data are used extensively for laser point processing. The software Trimble Business Center v.3.90, Blue Marble Geographic Calculator 2017, and PosPac MMS 8.1 SP3 are used for these processes.
2018-08-31T00:00:00
National Geodetic Survey
processor
QSI used RiProcess 1.8.5 to calculate laser point positioning of the Riegl VQ-880G data by associating SBET positions to each laser point return time, scan angle, intensity, etc. A raw laser point cloud is created in Riegl data format and erroneous points are filtered. Within RiProcess the RiHydro tool was used to classify water surface and create a water surface model. QSI used the green water surface points and as needed NIR water surface points to create water surface models. These models are used in the RiHydro refraction tool to determine angle of incidence and ranging time under water. They are created for a single swaths to ensure temporal differences and wave or water surface height variations between flight lines do not impact the refraction correction of the bathymetric data. All lidar data below water surface models were classified as water column and corrected for refraction. The green laser light travels at slower speed in water than air and its direction of travel is changed when entering water. The refraction tool corrects positioning of under water points by adjusting the ranging distance in water and horizontal position change due to the angle of refraction. Using raster-based QC methods, the output data is verified to ensure the refraction tool functioned properly. QSI used their proprietary LASMonkey refraction tool to correct some refraction in back bay/inland pond areas where RiHydro refraction was found to be inadequate.
Once all green data had been refracted by flight line all data was exported to LAS 1.2 format and are combined into 500 m x 500 m tiles. Data was then further calibrated using TerraScan, TerraModeler, and TerraMatch. QSI used custom algorithms in TerraScan to create the initial ground/submerged topography surface. Relative accuracy of the green swaths was compared to overlapping and adjacent swaths and verified through the use Delta-Z (DZ) orthos created using QSI's DZ Ortho creator. Absolute vertical accuracy of the calibrated data was assessed using ground RTK survey data and complete coverage was again verified.
QSI then performed manual editing to review all classification and improve the final topobathy surface. QSI's LasMonkey was used to update LAS header information, including all projection and coordinate reference system information. The final LiDAR data are in LAS format 1.2 and point data record format 3.
The classification scheme is as follows:
1-Unclassified
2-Ground
7-Noise
19-Overlap Default
20-Overlap Ground
21-Overlap Water Column
25-Water Column
26-Bathymetric Bottom or Submerged Topography
29-Submerged feature
30-Submerged Aquatic Vegetation*
31-Temporal Bathymetric Bottom
*Class 30 was submerged aquatic vegetation QSI identified within the bathymetric void shapes that precluded bathymetric bottom returns.
2018-10-31T00:00:00
The National Geodetic Survey reclassied points in classes 19 (overlap default), 20 (overlap ground), and 21 (overlap water column) to 1(unclassified)
The final classification scheme is as follows:
1-Unclassified
2-Ground
7-Noise
25-Water Column
26-Bathymetric Bottom or Submerged Topography
29-Submerged feature
30-Submerged Aquatic Vegetation
31-Temporal Bathymetric Bottom
2019-04-26T00:00:00
National Geodetic Survey
processor
The NOAA Office for Coastal Management (OCM) received files in las format. The files contained lidar elevation and intensity measurements of the Potomac River, Chesapeake Bay area.. OCM performed the following processing on the data for Digital Coast storage and provisioning purposes: 1. Converted from UTM Zone 17 to geographic coordinates 2. Sorted by gps time 3. Compressed the data using laszip
2019-04-29T00:00:00
Office for Coastal Management
processor
Lidar