2019 NOAA NGS Topobathy Lidar: Chesapeake Bay, MD
Data Set (DS) | National Geodetic Survey (NGS)GUID: gov.noaa.nmfs.inport:65553 | Updated: October 17, 2023 | Published / External
Summary
Short Citation
National Geodetic Survey, 2024: 2019 NOAA NGS Topobathy Lidar: Chesapeake Bay, MD, https://www.fisheries.noaa.gov/inport/item/65553.
Full Citation Examples
NOAA Chesapeake Bay MD1902 and MD1903 Topobathymetric lidar data were collected by NV5 Geospatial (NV5) using a Leica Chiroptera 4x system. The MD1903 acquisition spanned from 20191109-20191115 in 5 missions. The MD1902 acquisition spanned from 20191109-20191116 in 6 missions. The datasets include topobathymetric data in LAS format 1.4, point data record format 6, with the following classifications in accordance with project specifications and the American Society for Photogrammetry and Remote Sensing (ASPRS) classification standards:
1 - unclassified
2 - ground
7 - noise
40 - bathymetric bottom or submerged topography
41 - water surface
43 - submerged feature
45 - water column
46 - overlap bathy bottom - temporally different from a separate lift
71 - unclassified associated with areas of overlap bathy bottom/temporal bathymetric differences
72 - ground associated with areas of overlap bathy bottom/temporal bathymetric differences
81 - water surface associated with areas of overlap bathy bottom/temporal bathymetric differences
85 - water column associated with areas of overlap bathy bottom/temporal bathymetric differences
1 Overlap - edge clip
1 Withheld- green sensor returns within topographic areas
42 Synthetic - synthetic water surface
These data sets also includes lidar intensity values, number of returns, return number, time, and scan angle.
The 100 m buffered NOAA Chesapeake Bay MD1902 project area covers approximately 260.195 square kilometers in an area encompassing Severn River to Rhode River near Annapolis, Maryland. LAS files were compiled in 500 m x 500 m tiles. The MD1902 dataset is comprised of 1,460 - 500 m x 500 m LAS tiles.
The 100 m buffered NOAA Chesapeake Bay MD1903 project area covers approximately 260.195 square kilometers in an area encompassing West River to Dares Beach near Annapolis, Maryland. LAS files were compiled in 500 m x 500 m tiles. The MD1903 dataset is comprised of 1,569 - 500 m x 500 m LAS tiles.
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. Change to an orthometric vertical datum is one of the many options.
-
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. They will be in an orthometric datum.
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
BATHYMETRY, BEACHES, COASTAL BATHYMETRY, COASTAL ELEVATION, DIGITAL ELEVATION/TERRAIN MODEL (DEM), elevation, LAND SURFACE, LIDAR, TERRAIN ELEVATION, TOPOGRAPHY
Child Items
Type | Title |
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Entity | NOAA NGS Topobathy Lidar Class Scheme: Chesapeake Bay, MD |
Contact Information
Metadata Contact
NOAA Office for Coastal Management (NOAA/OCM)
coastal.info@noaa.gov
(843) 740-1202
https://coast.noaa.gov
Extents
-76.648208° W,
-76.423364° E,
39.114912° N,
38.855294° S
AOI for MD1902
2019-11-09 - 2019-11-16
Item Identification
Title: | 2019 NOAA NGS Topobathy Lidar: Chesapeake Bay, MD |
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Status: | Completed |
Publication Date: | 2021 |
Abstract: |
NOAA Chesapeake Bay MD1902 and MD1903 Topobathymetric lidar data were collected by NV5 Geospatial (NV5) using a Leica Chiroptera 4x system. The MD1903 acquisition spanned from 20191109-20191115 in 5 missions. The MD1902 acquisition spanned from 20191109-20191116 in 6 missions. The datasets include topobathymetric data in LAS format 1.4, point data record format 6, with the following classifications in accordance with project specifications and the American Society for Photogrammetry and Remote Sensing (ASPRS) classification standards: 1 - unclassified 2 - ground 7 - noise 40 - bathymetric bottom or submerged topography 41 - water surface 43 - submerged feature 45 - water column 46 - overlap bathy bottom - temporally different from a separate lift 71 - unclassified associated with areas of overlap bathy bottom/temporal bathymetric differences 72 - ground associated with areas of overlap bathy bottom/temporal bathymetric differences 81 - water surface associated with areas of overlap bathy bottom/temporal bathymetric differences 85 - water column associated with areas of overlap bathy bottom/temporal bathymetric differences 1 Overlap - edge clip 1 Withheld- green sensor returns within topographic areas 42 Synthetic - synthetic water surface These data sets also includes lidar intensity values, number of returns, return number, time, and scan angle. The 100 m buffered NOAA Chesapeake Bay MD1902 project area covers approximately 260.195 square kilometers in an area encompassing Severn River to Rhode River near Annapolis, Maryland. LAS files were compiled in 500 m x 500 m tiles. The MD1902 dataset is comprised of 1,460 - 500 m x 500 m LAS tiles. The 100 m buffered NOAA Chesapeake Bay MD1903 project area covers approximately 260.195 square kilometers in an area encompassing West River to Dares Beach near Annapolis, Maryland. LAS files were compiled in 500 m x 500 m tiles. The MD1903 dataset is comprised of 1,569 - 500 m x 500 m LAS tiles. |
Purpose: |
This lidar data was required by National Oceanic and Atmospheric Administration (NOAA) and 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. |
Supplemental Information: |
Data from MD1902 and MD1903 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. Depth values were adjusted per sensor to NOAA provided ground truth data. Bathymetric intensity values were normalized for water depth. Classes 2 (ground), 40 (submerged topography), and 43 (submerged object) were used to create the final DEMs. The full workflow used for this project will be documented in the NOAA Chesapeake Bay MD_1902_1903 Topobathymetric lidar final report. |
Keywords
Theme Keywords
Thesaurus | Keyword |
---|---|
Global Change Master Directory (GCMD) Science Keywords |
EARTH SCIENCE > LAND SURFACE
|
Global Change Master Directory (GCMD) Science Keywords |
EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY
|
Global Change Master Directory (GCMD) Science Keywords |
EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION
|
Global Change Master Directory (GCMD) Science Keywords |
EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION > DIGITAL ELEVATION/TERRAIN MODEL (DEM)
|
Global Change Master Directory (GCMD) Science Keywords |
EARTH SCIENCE > OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > BATHYMETRY
|
Global Change Master Directory (GCMD) Science Keywords |
EARTH SCIENCE > OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > BATHYMETRY > COASTAL BATHYMETRY
|
Global Change Master Directory (GCMD) Science Keywords |
EARTH SCIENCE > OCEANS > COASTAL PROCESSES > BEACHES
|
Global Change Master Directory (GCMD) Science Keywords |
EARTH SCIENCE > OCEANS > COASTAL PROCESSES > COASTAL ELEVATION
|
Global Change Master Directory (GCMD) Science Keywords |
EARTH SCIENCE > SPECTRAL/ENGINEERING > LIDAR
|
ISO 19115 Topic Category |
elevation
|
Spatial Keywords
Thesaurus | Keyword |
---|---|
Global Change Master Directory (GCMD) Location Keywords |
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > MARYLAND
|
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: | Model (digital) |
Distribution Liability: |
Any conclusions drawn from the analysis of this information are not the responsibility of NOAA, the Office for Coastal Management or its partners |
Data Set Credit: | National Oceanic and Atmospheric Administration (NOAA), National Geodetic Survey (NGS), Remote Sensing Division (RSD), Coastal Mapping Program (CMP) |
Support Roles
Data Steward
Date Effective From: | 2021 |
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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: | 2021 |
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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: | 2021 |
---|---|
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 |
Originator
Date Effective From: | 2021 |
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Date Effective To: | |
Contact (Organization): | National Geodetic Survey (NGS) |
Address: |
1315 East-West Hwy Silver Spring, MD 20910 |
URL: | https://geodesy.noaa.gov/ |
Extents
Currentness Reference: | Ground Condition |
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Extent Group 1
Extent Group 1 / Geographic Area 1
W° Bound: | -76.648208 | |
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E° Bound: | -76.423364 | |
N° Bound: | 39.114912 | |
S° Bound: | 38.855294 | |
Description |
AOI for MD1902 |
Extent Group 1 / Time Frame 1
Time Frame Type: | Range |
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Start: | 2019-11-09 |
End: | 2019-11-16 |
Extent Group 2
Extent Group 2 / Geographic Area 1
W° Bound: | -76.596687 | |
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E° Bound: | -76.445444 | |
N° Bound: | 38.880334 | |
S° Bound: | 38.522624 | |
Description |
AOI for MD1903 |
Extent Group 2 / Time Frame 1
Time Frame Type: | Range |
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Start: | 2019-11-09 |
End: | 2019-11-15 |
Spatial Information
Spatial Representation
Representations Used
Grid: | No |
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Vector: | Yes |
Text / Table: | No |
TIN: | No |
Stereo Model: | No |
Video: | No |
Reference Systems
Reference System 1
Coordinate Reference System |
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Access Information
Security Class: | Unclassified |
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Data Access Procedure: |
Data is available online for bulk or 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: | 2021-05 |
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End Date: | Present |
Download URL: | https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=9424 |
Distributor: | NOAA Office for Coastal Management (NOAA/OCM) (2021 - Present) |
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. Change to an orthometric vertical datum is one of the many options. |
File Type (Deprecated): | Zip |
Compression: | Zip |
Distribution 2
Start Date: | 2020-05 |
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End Date: | Present |
Download URL: | https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9424/ |
Distributor: | NOAA Office for Coastal Management (NOAA/OCM) (2021 - Present) |
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. They will be in an orthometric datum. |
File Type (Deprecated): | LAZ |
Distribution Format: | LAS/LAZ - LASer |
Compression: | Zip |
URLs
URL 1
URL: | https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9424/supplemental/extent_ngs_2019topobathy_chesBay_md_m9424.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 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://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9424/supplemental/NOAA_CB_1902_1903_Topobathymetric_Lidar_Report.pdf |
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Name: | Topobathymetric Lidar Data Report |
URL Type: |
Online Resource
|
File Resource Format: | |
Description: |
Topobathymetric Lidar Data Report |
Technical Environment
Description: |
OS Independent |
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Data Quality
Horizontal Positional Accuracy: |
Lidar horizontal accuracy is a function of Global Navigation Satellite System (GNSS) derived positional error, flying altitude, and INS derived attitude error. The obtained RMSEr value is multiplied by a conversion factor of 1.7308 to yield the horizontal component of the National Standards for Spatial Data Accuracy (NSSDA) reporting standard where a theoretical point will fall within the obtained radius 95 percent of the time (ACCr). Based on a flying altitude of 400 meters, an IMU error of 0.002 decimal degrees, and a GNSS positional error of 0.015 meters, the RMSEr value for the MD1902 and MD1903 project area is 0.064 meters, with a ACCr of 0.11 meters at the 95% confidence level. The project specification requires horizontal positions to be accurate to 1.0m(RMSE). |
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Vertical Positional Accuracy: |
Absolute accuracy was assessed using Non-Vegetated Vertical Accuracy (NVA) survey methods. Survey check points were evenly distributed as feasible throughout the project area. 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 ground classified lidar point cloud. NVA is a measure of the accuracy of lidar point data in open areas with level slope (less than 20Â 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 MD1902 data extent, 89 survey checkpoints were used to assess the submerged topography accuracy and in the MD1903 data extent, 23 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. Submerged topography points were tested separately. In the MD1903 data extent, 42 survey checkpoints were used to assess the submerged topography accuracy. Project specifications require submerged topography shall meet a vertical RMSE of QL2b specified in the Draft National Coastal Mapping strategy 1.0 which is equivalent to 0.30 m RMSE at a depth of 1 m. Please refer to the NOAA Chesapeake Bay MD_1902_1903 Topobathymetric lidar final data report for final accuracies. Vertical Positional Accuracy for MD1902 The MD1902 dataset Non-Vegetated Vertical Accuracy tested 0.064 m vertical accuracy at the 95% confidence level against the ground classified lidar point cloud in open terrain using 25 ground check points, based on RMSEz (0.033 m) x 1.9600. The MD1902 dataset submerged topography accuracy tested 0.111 m vertical accuracy at the 95% confidence level against the classified point cloud using 89 submerged check points, based on RMSEz (0.057 m) x 1.9600. Submerged topography checkpoints usually occur in depths up to 1m. Vertical Positional Accuracy for MD1903 The MD1903 dataset Non-Vegetated Vertical Accuracy tested 0.073 m vertical accuracy at the 95% confidence level against the ground classified lidar point cloud in open terrain using 23 ground check points, based on RMSEz (0.037 m) x 1.9600. The MD1903 dataset submerged topography accuracy tested 0.157 m vertical accuracy at the 95% confidence level against the classified point cloud using 43 submerged check points, based on RMSEz (0.080 m) x 1.9600. Submerged topography checkpoints usually occur in depths up to 1m. |
Completeness Report: |
Data covers the project boundary. |
Conceptual Consistency: |
Not applicable |
Data Management
Have Resources for Management of these Data Been Identified?: | Yes |
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Approximate Percentage of Budget for these Data Devoted to Data Management: | Unknown |
Do these Data Comply with the Data Access Directive?: | Yes |
Actual or Planned Long-Term Data Archive Location: | NCEI-CO |
How Will the Data Be Protected from Accidental or Malicious Modification or Deletion Prior to Receipt by the Archive?: |
Data is backed up to tape and to cloud storage. |
Lineage
Sources
Acquisition and Processing
Contact Role Type: | Originator |
---|---|
Contact Type: | Organization |
Contact Name: | NV5 Geospatial (NV5) |
Process Steps
Process Step 1
Description: |
Data for The NOAA Chesapeake Bay MD1903 Topobathymetric lidar project area was acquired by NV5 Geospatial (NV5) using a Leica Chiroptera 4x Topobathy lidar system. All derived LAS data is referenced to: Horizontal Datum-NAD83(2011) epoch: 2010.00 Projection-UTM Zone 18N Horizontal Units-meters Vertical Datum-GRS80 Ellipsoid Vertical Units-meters The collected lidar data were immediately processed in the field by NV5 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 8.3 SP3 and loaded into 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 raster generation using LAStools to develop an initial assessment of bathymetric coverage. NV5 reviewed all acquired flight lines to ensure complete coverage and positional accuracy of the laser points. These rasters were also used to create an initial product in Quick Look Coverage Maps. These Quick Look files are not fully processed data or final products but provide rapid assessment of approximate coverage and depth penetration. |
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Process Date/Time: | 2021-07-08 00:00:00 |
Process Contact: | NGS Communications and Outreach Branch |
Phone (Voice): | (301) 713-3242 |
Email Address: | ngs.infocenter@noaa.gov |
Process Step 2
Description: |
NV5 resolved kinematic corrections for aircraft position data using aircraft GNSS and Applanix's proprietary PP-RTX solution. When PP-RTX was not used NV5 conducted static Global Navigation Satellite System (GNSS) ground surveys (1 Hz recording frequency) using base stations over known monument locations during flights. After the airborne survey, 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 base station were performed to confirm antenna height measurements and to refine position accuracy. This data was used to correct the continuous on board measurements of the aircraft position recorded throughout the flight. A final smoothed best estimate trajectory (SBET) was developed that blends post-processed aircraft position with attitude data. Using the SBETs, sensor head position and attitude were then calculated throughout the survey. Trimble Business Center v.3.90, Blue Marble Geographic Calculator 2019, and PosPac MMS 8.3 SP3 were used for these processes. Following final SBET creation, NV5 used Leica Lidar Survey Studio (LSS) to calculate laser point positioning by associating SBET positions to each laser point return time, scan angle, and intensity. Leica LSS was used to derive a synthetic water surface to create a water surface model. Light travels at different speeds in air versus water and its direction of travel or angle is changed or refracted when entering the water column. The refraction tool corrects for this difference by adjusting the depth (distance traveled) and horizontal positioning (change of angle/direction) of the lidar data. All lidar data below water surface models were classified as water column to correct for refraction. Using raster-based QC methods, the output data is verified to ensure the refraction tool functioned properly. |
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Process Date/Time: | 2021-07-08 00:00:00 |
Process Step 3
Description: |
Once all data was refracted by flight line data was exported to LAS 1.4 format and combined into 500 m x 500 m tiles. Data were then further calibrated using TerraMatch. NV5 used custom algorithms in TerraScan to classify the initial ground/submerged topography surface points. Relative accuracy of overlapping swaths was compared and verified through the use Delta-Z (DZ) orthos created using NV5's Las Product Creator. Absolute vertical accuracy of the calibrated data was assessed using ground survey data and complete coverage was again verified. Post automated classification NV5 then performed manual editing to review all classification and improve the final topobathymetric surface. NV5'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 1.4 and point data record format 6. 1 - unclassified 2 - ground 7 - noise 40 - bathymetric bottom or submerged topography 41 - water surface 43 - submerged feature 45 - water column 46 - overlap bathy bottom - temporally different from a separate lift 71 - unclassified associated with areas of overlap bathy bottom/temporal bathymetric differences 72 - ground associated with areas of overlap bathy bottom/temporal bathymetric differences 81 - water surface associated with areas of overlap bathy bottom/temporal bathymetric differences 85 - water column associated with areas of overlap bathy bottom/temporal bathymetric differences 1 Overlap - edge clip 1 Withheld- green sensor returns within topographic areas 42 Synthetic - synthetic water surface |
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Process Date/Time: | 2021-07-08 00:00:00 |
Process Step 4
Description: |
The NOAA Office for Coastal Management (OCM) received files in laz format. The files contained lidar elevation and intensity measurements. The data were in UTM Zone 18 coordinates and ellipsoid elevations in meters. OCM performed the following processing on the data for Digital Coast storage and provisioning purposes: 1. Converted from UTM Zone 18 to geographic coordinates 2. Sorted by gps time |
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Process Date/Time: | 2021-10-08 00:00:00 |
Process Contact: | Office for Coastal Management (OCM) |
Child Items
Rubric scores updated every 15m
Type | Title | |
---|---|---|
Entity | NOAA NGS Topobathy Lidar Class Scheme: Chesapeake Bay, MD |
Catalog Details
Catalog Item ID: | 65553 |
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GUID: | gov.noaa.nmfs.inport:65553 |
Metadata Record Created By: | Maryellen Sault |
Metadata Record Created: | 2021-09-30 17:14+0000 |
Metadata Record Last Modified By: | SysAdmin InPortAdmin |
Metadata Record Last Modified: | 2023-10-17 16:12+0000 |
Metadata Record Published: | 2022-03-16 |
Owner Org: | NGS |
Metadata Publication Status: | Published Externally |
Do Not Publish?: | N |
Metadata Last Review Date: | 2022-03-16 |
Metadata Review Frequency: | 1 Year |
Metadata Next Review Date: | 2023-03-16 |