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Short Citation:
OCM Partners, 2024: 2021 USGS Lidar: Central Eastern Massachusetts, https://www.fisheries.noaa.gov/inport/item/69417.

Item Identification

Title: 2021 USGS Lidar: Central Eastern Massachusetts
Short Name: ma2021_cent_east_m9777_metadata
Status: Completed
Creation Date: 2021-01-01
Publication Date: 2022-06-17
Abstract:

Product: Classified LAS 1.4 files, formatted to 6,038 individual 1,500m x 1,500m tiles covering the Central Eastern Massachusetts project area.

Geographic Extent: This dataset and derived products encompass an area covering approximately 5,246 Square Miles of Massachusetts.

Dataset Description: The Central Eastern Massachusetts Lidar project called for the planning, acquisition, and processing of lidar data collected to Quality Level 1 (QL1) standards. Project specifications are based on the U.S. Geological Survey National Geospatial Program LIDAR Base Specification 2020 Revision A. The data was developed based on the NAD83(2011) horizontal datum and the NAVD88 Geoid 18 vertical datum. Data was projected in UTM Zone 19 N, Meters. Lidar data was delivered as calibrated and classified LAS 1.4 files.

Non-Vegetated Vertical Accuracy (NVA) was assessed using 129 check points located on bare earth in clear, unobstructed areas.

Vegetated Vertical Accuracy (VVA) was assessed using 95 check points in Tall Grass, Forest, and Shrub landcover types. Single swath nominal pulse spacing (NPS) was designed to be 0.50 m at nadir.

Aggregate Nominal Pulse Spacing (ANPS) was calculated to be 0.27 m using all valid first return points.

Derived products include: Intensity Imagery, Hydro-flattened Bare Earth Digital Elevation Models (DEMs), Highest Hit Digital Surface Models (DSMs), and 3D waters edge breaklines.

Ground Condition: Ground condition was free of snow and acquisition occurred free of smoke, fog and cloud cover, and occurred in coordination with low tide windows.

Point Classes: 1 - Unclassified, 2 - Ground, 3 - Low Vegetation (0.5 - 2 meters), 4 - Medium Vegetation (2 - 5 meters), 5 - High Vegetation (> 5 meters), 6 - Buildings, 7 - Low Noise, 9 - Water, 17 - Bridge Decks, 18 - High Noise, 20 - Ignored Ground, 22 - Temporal Exclusion

This metadata record supports the data entry in the NOAA Digital Coast Data Access Viewer (DAV). For this data set, the DAV is leveraging the Entwine Point Tiles (EPT) hosted by USGS on Amazon Web Services.

Purpose:

The purpose of the lidar data was to produce a high accuracy 3D dataset that meets all necessary standards laid out by the 3D Elevation Program and the Central Eastern Massachusetts contract. The lidar point cloud data were used to create classified lidar LAS files, intensity images, hydro-flattened DEMs, highest hit DSMs, and 3D breaklines of rivers and lakes within the study area.

Supplemental Information:

USGS Contract No. G16PC00016

CONTRACTOR: NV5 Geospatial.

Ground Control Points were acquired and calibrated by NV5 Geospatial.

All lidar data acquisition, calibration, and follow-on processing were completed by NV5 Geospatial.

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

"ldrspec" : "U.S. Geological Survey National Geospatial Program LIDAR Base Specification 2020 Revision A",

"ldrsens" : "Riegl VQ-1560i",

"ldrmaxnr" : "15",

"ldrnps" : "0.50",

"ldrdens" : "4",

"ldranps" : "0.27",

"ldradens" : "13.75",

"ldrfltht" : "1,500",

"ldrfltsp" : "160",

"ldrscana" : "58.52",

"ldrscanr" : "Uniform Point Spacing",

"ldrpulsr" : "1000",

"ldrpulsd" : "3.0",

"ldrpulsw" : "0.90",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.25",

"ldrswatw" : "1,681",

"ldrswato" : "20",

"ldrgeoid" : "Geoid 18"

},

"ldrinfo" : {

"ldrspec" : "U.S. Geological Survey National Geospatial Program LIDAR Base Specification 2020 Revision A",

"ldrsens" : "Optech Galaxy-T2000",

"ldrmaxnr" : "8",

"ldrnps" : "5.5",

"ldrdens" : "0.43",

"ldranps" : "13.75",

"ldradens" : "0.27",

"ldrfltht" : "1,829",

"ldrfltsp" : "120",

"ldrscana" : "38",

"ldrscanr" : "95",

"ldrpulsr" : "1100",

"ldrpulsd" : "2.5",

"ldrpulsw" : "0.75",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.23",

"ldrswatw" : "1,259",

"ldrswato" : "30",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid 18"

},

"ldraccur" : {

"ldrchacc" : "0",

"rawnva" : "0",

"rawnvan" : "0"

},

"lasinfo" : {

"lasver" : "1.4",

"lasprf" : "6",

"laswheld" : "Withheld (ignore) points are identified in these files using the standard LAS Withheld bit.",

"lasolap" : "Swath "overage" points were identified in these files using the standard LAS overlap bit.",

"lasintr" : "16",

"lasclass" : {

"clascode" : "1",

"clasitem" : "Processed, but Unclassified"

},

"lasclass" : {

"clascode" : "2",

"clasitem" : "Bare earth ground"

},

"lasclass" : {

"clascode" : "3",

"clasitem" : "Low Vegetation"

},

"lasclass" : {

"clascode" : "4",

"clasitem" : "Medium Vegetation"

},

"lasclass" : {

"clascode" : "5",

"clasitem" : "High Vegetation"

},

"lasclass" : {

"clascode" : "6",

"clasitem" : "Building"

},

"lasclass" : {

"clascode" : "7",

"clasitem" : "Low Noise"

},

"lasclass" : {

"clascode" : "9",

"clasitem" : "Water"

},

"lasclass" : {

"clascode" : "17",

"clasitem" : "Bridge Decks"

},

"lasclass" : {

"clascode" : "18",

"clasitem" : "High Noise"

},

"lasclass" : {

"clascode" : "20",

"clasitem" : "Ignored Ground Near Breaklines"

},

"lasclass" : {

"clascode" : "22",

"clasitem" : "Temporal Exclusion"

}

}}

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

Spatial Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Location Keywords
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA
Global Change Master Directory (GCMD) Location Keywords
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > MASSACHUSETTS
Global Change Master Directory (GCMD) Location Keywords
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > MASSACHUSETTS > BOSTON
Global Change Master Directory (GCMD) Location Keywords
VERTICAL LOCATION > LAND SURFACE

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
City: Charleston
State/Province: SC

Data Set Information

Data Set Scope Code: Data Set
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: NV5 Geospatial, USGS

Support Roles

Data Steward

CC ID: 1222901
Date Effective From: 2023
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: 1222919
Date Effective From: 2023
Date Effective To:
Contact (Organization): U.S. Geological Survey
Address: 12201 Sunrise Valley Drive
Reston, VA 20191
USA
URL: USGS Home

Distributor

CC ID: 1222900
Date Effective From: 2023
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: 1222902
Date Effective From: 2023
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: 1222903
Date Effective From: 2023
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: 1222906
W° Bound: -72.054315
E° Bound: -69.91911
N° Bound: 42.903228
S° Bound: 41.220432

Extent Group 1 / Time Frame 1

CC ID: 1222905
Time Frame Type: Range
Start: 2021-03-20
End: 2021-04-24

Spatial Information

Spatial Representation

Representations Used

Grid: No
Vector: Yes
Text / Table: No
TIN: No
Stereo Model: No
Video: No

Reference Systems

Reference System 1

CC ID: 1222920

Coordinate Reference System

CRS Type: Projected
EPSG Code: EPSG:3857
EPSG Name: WGS 84 / Pseudo-Mercator
See Full Coordinate Reference System Information

Reference System 2

CC ID: 1222921

Coordinate Reference System

CRS Type: Vertical
EPSG Code: EPSG:5703
EPSG Name: NAVD88 height
See Full Coordinate Reference System Information

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

CC ID: 1222907
Start Date: 2023-03-10
End Date: Present
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=9777/details/9777
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2023 - 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

CC ID: 1222908
Start Date: 2023
End Date: Present
Download URL: https://rockyweb.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/MA_CentralEastern_2021_B21/
Distributor: U.S. Geological Survey (2023 - Present)
File Name: Bulk Download
Description:

Bulk download of data files in LAZ format, UTM Zone 19N (NAD83 2011), meters coordinates and NAVD88 (GEOID18) heights in meters.

File Type (Deprecated): LAZ
Distribution Format: LAS/LAZ - LASer
Compression: Zip

URLs

URL 1

CC ID: 1222898
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 2

CC ID: 1223117
URL: https://rockyweb.usgs.gov/vdelivery/Datasets/Staged/Elevation/metadata/MA_CentralEastern_2021_B21/
Name: USGS Additional Info
URL Type:
Online Resource
Description:

Link to the reports, breaklines, metadata, spatial metadata, and shapefiles.

URL 3

CC ID: 1223118
URL: https://rockyweb.usgs.gov/vdelivery/Datasets/Staged/Elevation/metadata/MA_CentralEastern_2021_B21/USGS_MA_CentralEastern_2021_B21_Project_Report.pdf
Name: USGS Project Report
URL Type:
Online Resource
File Resource Format: pdf
Description:

Link to the USGS project report which provides information about the project, the vertical accuracy results, the point classifications and the sensors used.

URL 4

CC ID: 1223119
URL: https://rockyweb.usgs.gov/vdelivery/Datasets/Staged/Elevation/metadata/MA_CentralEastern_2021_B21/MA_CentralEastern_1_2021/reports/Central_East_MA_NIR_lidar_Report_Final_220803_Revised.pdf
Name: Lidar Report
URL Type:
Online Resource
File Resource Format: pdf
Description:

Link to the lidar report.

URL 5

CC ID: 1223120
URL: https://s3-us-west-2.amazonaws.com/usgs-lidar-public/MA_CentralEastern_1_2021/ept.json
Name: USGS Entwine Point Tile (EPT) - Block 1
URL Type:
Online Resource
File Resource Format: json
Description:

Entwine Point Tile (EPT) is a simple and flexible octree-based storage format for point cloud data. The data is organized in such a way that the data can be reasonably streamed over the internet, pulling only the points you need. EPT files can be queried to return a subset of the points that give you a representation of the area. As you zoom further in, you are requesting higher and higher densities. A dataset in EPT will contain a lot of files, however, the ept.json file describes all the rest. The EPT file can be used in Potree and QGIS to view the point cloud.

URL 6

CC ID: 1223122
URL: https://usgs.entwine.io/data/view.html?r=[%22https://s3-us-west-2.amazonaws.com/usgs-lidar-public/MA_CentralEastern_1_2021/ept.json%22,%22https://s3-us-west-2.amazonaws.com/usgs-lidar-public/MA_CentralEastern_2_2021/ept.json%22]
Name: USGS 3D View
URL Type:
Online Resource
Description:

Link to view the point cloud, using the Entwine Point Tile (EPT) format, in the 3D Potree viewer.

URL 7

CC ID: 1224591
URL: https://s3-us-west-2.amazonaws.com/usgs-lidar-public/MA_CentralEastern_2_2021/ept.json
Name: USGS Entwine Point Tile (EPT) - Block 2
URL Type:
Online Resource
File Resource Format: json
Description:

Entwine Point Tile (EPT) is a simple and flexible octree-based storage format for point cloud data. The data is organized in such a way that the data can be reasonably streamed over the internet, pulling only the points you need. EPT files can be queried to return a subset of the points that give you a representation of the area. As you zoom further in, you are requesting higher and higher densities. A dataset in EPT will contain a lot of files, however, the ept.json file describes all the rest. The EPT file can be used in Potree and QGIS to view the point cloud.

Technical Environment

Description:

Applanix PosPac 8.5, PofImport 1.7.4, Georun v.6.1.1, BayesMap-StripAlign v.2.19, Microstation CONNECT version 10, TerraScan Version 20, TerraModeler Version 20, TerraMatch Version 20, ESRI ArcGIS 10.3, Windows 10 Operating System

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. All areas surveyed at a flying altitude of 1500 meters, with an IMU error of 0.002 decimal degrees, and a GNSS positional error of 0.015 meters, were produced to meet 0.16 meters horizontal accuracy at the 95% confidence level (or 0.09 m RMSEr). All areas using a flying altitude of 1,829 meters, an IMU error of 0.002 decimal degrees, and a GNSS positional error of 0.015 meters, were produced to meet 0.20 meters horizontal accuracy at the 95% confidence level (or 0.11 m RMSEr).

Vertical Positional Accuracy:

This data set was produced to meet ASPRS Positional Accuracy Standard for Digital Geospatial Data (2014) for a 10-cm RMSEz Vertical Accuracy Class. Specifications for this project require that the NVA be 0.196 meters or better AccuracyZ at 95% confidence level.

USGS Determined Vertical Accuracy

Non-Vegetated Vertical Accuracy (NVA) = 7.35 cm at 95% Confidence Level (3.7 cm RMSE)

Vegetated Vertical Accuracy (VVA) = 13.58 cm at 95th Percentile

Completeness Report:

These LAS data files include all data points collected. No points have been removed or excluded. A visual qualitative assessment was performed to ensure data completeness. No void areas or missing data exist. The raw point cloud is of good quality and data passes Non-Vegetated Vertical Accuracy specifications.

Conceptual Consistency:

Classified LAS files were tested by NV5 Geospatial for vertical accuracy. All data is seamless from one tile to the next, no gaps or no data areas.

Data Management

Have Resources for Management of these Data Been Identified?: Yes
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

Lineage Statement:

The NOAA Office for Coastal Management (OCM) ingested references to the USGS Entwine Point Tile (EPT) files hosted on Amazon Web Services (AWS) into the Digital Coast Data Access Viewer (DAV). The DAV accesses the point cloud as it resides on AWS under the usgs-lidar-public-container.

Sources

USGS AWS Entwine Point Tile

CC ID: 1223125
Contact Role Type: Publisher
Contact Type: Organization
Contact Name: USGS
Citation URL: https://s3-us-west-2.amazonaws.com/usgs-lidar-public/MA_CentralEastern_2_2021/ept.json
Citation URL Name: Entwine Point Tile file for MA_CentralEastern_2_2021

USGS AWS Entwine Point Tile

CC ID: 1223124
Contact Role Type: Publisher
Contact Type: Organization
Contact Name: USGS
Citation URL: https://s3-us-west-2.amazonaws.com/usgs-lidar-public/MA_CentralEastern_1_2021/ept.json
Citation URL Name: Entwine Point Tile file for MA_CentralEastern_1_2021

Process Steps

Process Step 1

CC ID: 1222893
Description:

Lidar Pre-Processing:

1. Review flight lines and data to ensure complete coverage of the study area and positional accuracy of the laser points.

2. Resolve kinematic corrections for aircraft position data using kinematic aircraft GPS and static ground GPS data.

3. Develop a smoothed best estimate of trajectory (SBET) file that blends post-processed aircraft position with sensor head position and attitude recorded throughout the survey.

4. Calculate laser point position by associating SBET position to each laser point return time, scan angle, intensity, etc. Create raw laser point cloud data for the entire survey in *.las format. Convert data to orthometric elevations by applying a Geoid 18 correction.

5. Import raw laser points into manageable blocks to perform manual relative accuracy calibration and filter erroneous points. Classify ground points for individual flight lines.

6. Using ground classified points per each flight line, test the relative accuracy. Perform automated line-to-line calibrations for system attitude parameters (pitch, roll, heading), mirror flex (scale) and GPS/IMU drift. Calculate calibrations on ground classified points from paired flight lines and apply results to all points in a flight line. Use every flight line for relative accuracy calibration.

7. Adjust the point cloud by comparing ground classified points to supplemental ground control points.

Process Date/Time: 2022-01-27 00:00:00

Process Step 2

CC ID: 1222894
Description:

Lidar Post-Processing:

1. Classify data to ground and other client designated classifications using proprietary classification algorithms.

2. Manually QC data classification

3. After completion of classification and final QC approval, calculate final NVA, VVA, and density information for the project using ground control quality check points.

Process Date/Time: 2022-01-27 00:00:00

Process Step 3

CC ID: 1223126
Description:

Original point clouds in LAS/LAZ format were restructured as Entwine Point Tiles and stored on Amazon Web Services. The data were re-projected horizontally to WGS84 web mercator (EPSG 3857) and no changes were made to the vertical of NAVD88 (GEOID18), meters.

Process Contact: U.S. Geological Survey

Process Step 4

CC ID: 1223151
Description:

The NOAA Office for Coastal Management (OCM) created references to the Entwine Point Tile (EPT) files that were ingested into the NOAA Digital Coast Data Access Viewer (DAV). No changes were made to the data. The DAV will access the point cloud as it resides on Amazon Web Services (AWS) under the usgs-lidar-public container.

These are the AWS URLs being accessed:

https://s3-us-west-2.amazonaws.com/usgs-lidar-public/MA_CentralEastern_1_2021/ept.json

https://s3-us-west-2.amazonaws.com/usgs-lidar-public/MA_CentralEastern_2_2021/ept.json

Process Date/Time: 2023-01-01 00:00:00
Process Contact: U.S. Geological Survey

Catalog Details

Catalog Item ID: 69417
GUID: gov.noaa.nmfs.inport:69417
Metadata Record Created By: Rebecca Mataosky
Metadata Record Created: 2023-03-10 21:37+0000
Metadata Record Last Modified By: Rebecca Mataosky
Metadata Record Last Modified: 2024-04-29 17:35+0000
Metadata Record Published: 2023-03-13
Owner Org: OCMP
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Last Review Date: 2023-03-13
Metadata Review Frequency: 1 Year
Metadata Next Review Date: 2024-03-13