Short Citation:
Office for Coastal Management, 2021: 2017 NOAA/MCP Topobathy Lidar: Blue Hill Bay, ME - SHOALS Sensor, https://www.fisheries.noaa.gov/inport/item/52596.

Item Identification

Title: 2017 NOAA/MCP Topobathy Lidar: Blue Hill Bay, ME - SHOALS Sensor
Short Name: me2017_blue_hill_bay_shoals_m8526_metadata
Status: Completed
Abstract:

Fugro was contracted in July 2017 by the State of Maine Department of Marine Resources (SMDMR), Maine Coastal Program (MCP), and the NOAA Office for Coastal Management (OCM) to conduct an Airborne LiDAR Bathymetry (ALB) survey in the vicinity of Blue Hill Bay in Maine, and to deliver fully processed and verified hydrographic survey data.The ALB survey was conducted with the SHOALS-1000T and Riegl VQ-820-G lidar systems in a concurrent acquisition. The SHOALS system, with a high power laser, provided the better probability for deep sounding detections at a reduced point density (about 0.15 pts/m2); whilst the VQ-820-Q provided high density coverage (up to 8.5 pts/m2) but at reduced depth detection.

This metadata record describes the topographic and bathymetric LiDAR elevations generated from data collected with the SHOALS-1000T LiDAR system along Blue Hill Bay on the coastline of Maine. Data were collected by Fugro for NOAA OCM. The SHOALS system is a bathymetric LiDAR sensor for use in coastal mapping and charting activities because the laser's ability to penetrate the water column and detect targets up to 2.5 times the Secchi disk depth. Survey coverage was based on a delimiting polygon provided by NOAA OCM, which envelopes the area between the 0 m contour (NAVD88) down to approximated -10 meters. An additional horizontal buffer of 100 meters from the 0 m contour expanded the survey area coverage to include the adjacent emerged topography. SHOALS data have been processed on Optech SHOALS-GCS and QPS Fledermaus software packages for: auto-processing; calibration, cleaning and editing, validation, basic classification, and exported to LAS format.

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.

A topographic and bathymetric reflectance raster are also available. These data are available for download at the link provided in the URL section of this metadata record.

A link to custom download the concurrently collected topographic and bathymetric data (collected with the Riegl VQ-820-G lidar system) is provided in the URL section of this metadata record.

Purpose:

Conduct an Airborne Bathymetric LiDAR survey over Blue Hill Bay and deliver point cloud data correctly georeferenced and processed for refraction correction of underwater points. Bathymetric data will be used for improving digital elevation models and mapping to characterize nearshore benthic habitats; improve coastal flood inundation predictions; and provide accurate topographic/bathymetric digital elevation models for modeling, engineering, and planning needs.

Supplemental Information:

Water turbidity conditions at the time of survey prevented full bottom coverage results on the assigned areas. Every effort was made to recover as much valid point depths; gaps in the coverage are mostly caused by negative bottom detection or by the removal of data below the accuracy tolerance.

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 > Bathymetry/Seafloor Topography > Seafloor Topography
Global Change Master Directory (GCMD) Science Keywords Earth Science > Oceans > Coastal Processes > Coastal Elevation
ISO 19115 Topic Category elevation
ISO 19115 Topic Category imageryBaseMapsEarthCover
ISO 19115 Topic Category oceans
None Bathymetry
None beach
None DEM
None digital elevation model
None erosion
None LAS
None laser
None lidar
None National Oceanic and Atmospheric Administration
None Point data
None SHOALS
None Topography

Spatial Keywords

Thesaurus Keyword
Geographic Names Information System Blue Hill Bay
Geographic Names Information System U.S. East Coast
Global Change Master Directory (GCMD) Location Keywords Continent > North America > United States Of America > Maine
Global Change Master Directory (GCMD) Location Keywords Vertical Location > Land Surface
Global Change Master Directory (GCMD) Location Keywords Vertical Location > Seafloor
None U.S. Coastline

Instrument Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Instrument Keywords Earth Remote Sensing Instruments > Active Remote Sensing > Profilers/Sounders > Lidar/Laser Sounders > LIDAR > Light Detection and Ranging

Platform Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Platform Keywords Aircraft > Aircraft

Physical Location

Organization: Office for Coastal Management
City: Charleston
State/Province: SC

Data Set Information

Data Set Scope Code: Data Set
Data Set Type: Elevation
Maintenance Frequency: As Needed
Data Presentation Form: Point Cloud (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 and the Maine Coastal Program

Support Roles

Data Steward

CC ID: 753401
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

CC ID: 753402
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

CC ID: 753403
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

CC ID: 753404
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

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 753407
W° Bound: -68.566
E° Bound: -68.432
N° Bound: 44.313
S° Bound: 44.194

Extent Group 1 / Time Frame 1

CC ID: 753406
Time Frame Type: Range
Start: 2017-06-25
End: 2017-07-05
Description:

Data collected: June 25, 29, July 5, 2017

Access Information

Security Class: Unclassified
Data Access Procedure:

Data is available online for custom and bulk 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

CC ID: 753408
Start Date: 2018
End Date: Present
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=8526
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

CC ID: 753409
Start Date: 2018
End Date: Present
Download URL: https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/8526
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: LAZ

URLs

URL 1

CC ID: 753397
URL: https://coast.noaa.gov/
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

CC ID: 753398
URL: https://coast.noaa.gov/dataviewer/
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

CC ID: 753399
URL: https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/8526/supplemental/me2017_blue_hill_bay_shoals_m8526.kmz
Name: Browse graphic
URL Type:
Browse Graphic
File Resource Format: KML
Description:

This graphic displays the footprint for this lidar data set.

URL 4

CC ID: 753400
URL: https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/8526/supplemental/me2017_blue_hill_bay_shoals_m8526_report.pdf
Name: Dataset report
URL Type:
Online Resource
File Resource Format: PDF
Description:

Link to data set report.

URL 5

CC ID: 753444
URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=8528
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.

URL 6

CC ID: 753551
URL: https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/8526/supplemental/shoals_reflectance.zip
URL Type:
Online Resource
Description:

Link to the bathymetric and topographic reflectance rasters.

URL 7

CC ID: 753552
URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=8525
URL Type:
Online Resource
Description:

Link to custom download the concurrently collected topographic and bathymetric data (collected with the RIEGL VQ-820-G lidar system).

Data Quality

Horizontal Positional Accuracy:

The positions were obtained using post processed GNSS methods. The horizontal accuracy is better than ±4.49 m (2-sigma) at ground level above water.

Vertical Positional Accuracy:

The vertical accuracy is better than ±0.70 m (2-sigma) at laser extinction level below water.

Completeness Report:

Gaps in coverage are due to water quality conditions at the time of survey.

Conceptual Consistency:

The data provided in these files were constricted to IHO SP-54 Order 1b accuracy standards.

Lineage

Process Steps

Process Step 1

CC ID: 753394
Description:

The airborne raw files from the SHOALS sensor are downloaded into SHOALS-GCS software version 6.32. The system collects bathymetric LiDAR data at 2.5 kHz Pulse Repetition Rate for an approximated point density of 0.15 pts/m2 at 400 m altitude (AGL) and 100 kts (speed over ground). The SHOALS system also collects RGB imagery at 1 Hz using a Prosilica GX330 digital camera. Aircraft position, velocity, angular and acceleration information collected with an Applanix POS AV 510 v6 equipment were processed using Applanix POSPac v 7.1 software to produce a Smoothed Best Estimate Trajectory (SBET) solution file that is used by RiProcess to produce 3D positions for each LiDAR shot (point clouds). SHOALS-GCS auto-processing routine estimates the water surface and bottom surface points for each laser shot and applied the refraction correction automatically. Upon inspection and QA/QC in Fledermaus software version 7.7, anomalous data were flagged as invalid and bathymetry properly validated. All LiDAR points including bathymetric, topographic, water surface, noise and rejections were exported to LAS format. Elevations referenced to NAVD88 datum were reduced with the application with VDatum v3.6.1. and GEOID12b. Data was exported to LAS format 1.4 for delivery. LAS data has the following classification: Emerged and topographic points (1), Noise and Rejections (7), Bathymetry (40), Derived water surface (42), and Submerged objects (wrecks, rocks, pilings) (43).

Process Step 2

CC ID: 753395
Description:

The delivered LAS files were reviewed and processed to classify the point cloud and compute vertical accuracy. A variety of LAStools executables were used to tile the swaths, classify points (noise, ground, and bathymetric points), generate gridded products, and perform the final quantitative accuracy assessment. Global Mapper was used to perform qualitative assessments of the point clouds and gridded products at each step of the classification process. ArcGIS Pro was used to organize and visualize all delivered products and generate web services for team reviews. The final classification includes class 1 (unclassified), class 2 (bare ground), class 7 (low noise), class 40 (bathymetric point), class 42 (derived water surface), and class 43 (submerged objects).

Process Date/Time: 2018-04-01 00:00:00

Process Step 3

CC ID: 753443
Description:

The NOAA Office for Coastal Management (OCM) received 92 las files. The files contained topobathy elevation and intensity measurements in Blue Hill Bay along the coastline of Maine. The data were set to NAD83 2011 UTM Zone 19 North in meters and NAVD88 (Geoid12B) elevations in meters. The data were classified as: 1 -Unclassified, 2 - Ground, 7 - Low Noise, 40 - Bathymetry, 42 - Derived Water Surface. OCM processed all classifications of points to the Digital Coast Data Access Viewer (DAV). Classes available on the DAV are: 1, 2, 7, 40, 42.

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 las 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 las files to convert from orthometric (NAVD88) elevations to ellipsoid elevations using the Geoid 12B model, to convert from NAD83 2011 UTM Zone 19 North 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.

Process Date/Time: 2018-05-09 00:00:00
Process Contact: Office for Coastal Management (OCM)

Catalog Details

Catalog Item ID: 52596
Metadata Record Created By: Rebecca Mataosky
Metadata Record Created: 2018-05-09 10:41+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2019-07-02 15:17+0000
Metadata Record Published: 2018-05-10
Owner Org: OCM
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Next Review Date: 2019-05-11