2018 Town of Nantucket Lidar: Nantucket Island, MA
Data Set (DS) | OCM Partners (OCMP)GUID: gov.noaa.nmfs.inport:67485 | Updated: October 17, 2023 | Published / External
Summary
Short Citation
OCM Partners, 2024: 2018 Town of Nantucket Lidar: Nantucket Island, MA, https://www.fisheries.noaa.gov/inport/item/67485.
Full Citation Examples
Product: These lidar data are processed Classified LAS 1.4 files, formatted to 1,577 individual 1250 ft x 1250 ft tiles; used to create intensity images, 3D breaklines and hydro-flattened DEMs as necessary.
Geographic Extent: Nantucket County Massachusetts, covering approximately 91 square miles.
Dataset Description: The Nantucket project called for the Planning, Acquisition, processing and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.7 meter. 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), State Plane, Feet and vertical datum of NAVD88 (GEOID12B), Feet. Lidar data was delivered as processed Classified LAS 1.4 files, formatted to 1,577 individual 1250 ft x 1250 ft tiles, as tiled Intensity Rasters, and as tiled bare-earth DEM; all tiled to the same 1250 ft x 1250 ft schema.
Ground Conditions: Lidar was collected in early to mid 2018, 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, Sanborn Map Company, Inc. established a total of 20 ground control points that were used to calibrate and validate the lidar to known ground locations established throughout the project area.
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.
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
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
-70.3240401506° W,
-69.9511498712° E,
41.3971284252° N,
41.2321234447° S
2018-05-01 - 2018-10-15
Item Identification
Title: | 2018 Town of Nantucket Lidar: Nantucket Island, MA |
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Short Name: | ma2018_nantucket_m9551_metadata |
Status: | Completed |
Creation Date: | 2018 |
Publication Date: | 2018-10-15 |
Abstract: |
Product: These lidar data are processed Classified LAS 1.4 files, formatted to 1,577 individual 1250 ft x 1250 ft tiles; used to create intensity images, 3D breaklines and hydro-flattened DEMs as necessary. Geographic Extent: Nantucket County Massachusetts, covering approximately 91 square miles. Dataset Description: The Nantucket project called for the Planning, Acquisition, processing and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.7 meter. 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), State Plane, Feet and vertical datum of NAVD88 (GEOID12B), Feet. Lidar data was delivered as processed Classified LAS 1.4 files, formatted to 1,577 individual 1250 ft x 1250 ft tiles, as tiled Intensity Rasters, and as tiled bare-earth DEM; all tiled to the same 1250 ft x 1250 ft schema. Ground Conditions: Lidar was collected in early to mid 2018, 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, Sanborn Map Company, Inc. established a total of 20 ground control points that were used to calibrate and validate the lidar to known ground locations established throughout the project area. 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. |
Purpose: |
To acquire detailed surface elevation data for use in conservation planning, design, research, floodplain mapping, dam safety assessments and elevation modeling, etc. Classified LAS files are used to show the manually reviewed bare-earth surface. This allows the user to create Intensity Images, Breaklines and Raster DEM. The purpose of these lidar data was to produce high accuracy 3D hydro-flattened Digital Elevation Model (DEM) with a 2 foot cell size. These raw lidar point cloud data were used to create classified lidar LAS files, intensity images, 3D breaklines, and hydro-flattened DEMs as necessary. |
Supplemental Information: |
CONTRACTOR: Sanborn Map Company, Inc SUBCONTRACTOR: Geomni Lidar data were acquired Geomni. All follow-on 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" : "Leica CityMapper", "ldrmaxnr" : "15", "ldrnps" : "0.48", "ldrdens" : "4.4", "ldranps" : "0.43", "ldradens" : "5.5", "ldrfltht" : "2250", "ldrfltsp" : "145", "ldrscana" : "40", "ldrscanr" : "61.6", "ldrpulsr" : "306", "ldrpulsd" : "4", "ldrpulsw" : "0.53", "ldrwavel" : "1064", "ldrmpia" : "1", "ldrbmdiv" : "0.25", "ldrswatw" : "581", "ldrswato" : "25", "ldrgeoid" : "National Geodetic Survey (NGS) Geoid12B" }, "ldraccur" : {
"ldrchacc" : "0.5", "rawnva" : "0.227", "rawnvan" : "20", "clsnva" : "0.216", "clsnvan" : "20" }, "lasinfo" : {
"lasver" : "1.4", "lasprf" : "6", "laswheld" : "Withheld (ignore) points were 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" : "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
|
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 |
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 |
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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: | Sanborn Map Company, Inc., Town of Nantucket |
Support Roles
Data Steward
Date Effective From: | 2022 |
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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: | 2022 |
---|---|
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: | 2022 |
---|---|
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: | 2022 |
---|---|
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: | -70.3240401506 | |
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E° Bound: | -69.9511498712 | |
N° Bound: | 41.3971284252 | |
S° Bound: | 41.2321234447 |
Extent Group 1 / Time Frame 1
Time Frame Type: | Range |
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Start: | 2018-05-01 |
End: | 2018-10-15 |
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 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: | 2022-06-29 |
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End Date: | Present |
Download URL: | https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=9551/details/9551 |
Distributor: | NOAA Office for Coastal Management (NOAA/OCM) (2022 - 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: | 2022-06-29 |
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End Date: | Present |
Download URL: | https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9551/index.html |
Distributor: | NOAA Office for Coastal Management (NOAA/OCM) (2022 - 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://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 2
URL: | https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=9552/details/9552 |
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Name: | Custom DEM Download |
URL Type: |
Online Resource
|
File Resource Format: | Zip |
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 3
URL: | https://coast.noaa.gov/lidar/viewer/v/noaapotree.html?m=9551&g=geoid18 |
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Name: | Potree 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 4
URL: | https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/entwine/geoid18/9551/ept.json |
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Name: | Entwine Point Tiles (EPT) |
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 5
URL: | https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9551/supplemental/312018207_Nantucket_MA_Ortho_Lidar_Report_508OCM.pdf |
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Name: | Lidar Report |
URL Type: |
Online Resource
|
File Resource Format: | |
Description: |
Link to the lidar report. |
URL 6
URL: | https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9551/supplemental/ma2018_nantucket_m9551.kmz |
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Name: | Browse Graphic |
URL Type: |
Browse Graphic
|
File Resource Format: | KML |
Description: |
Link to the data set footprint. |
Data Quality
Vertical Positional Accuracy: |
The required accuracy (ACCz) is: 0.643 ft at a 95% confidence level, derived according to NSSDA, i.e., based on RMSE of 0.328 ft in the bare earth and urban land cover classes. The Vertical Accuracy was tested with 20 control points located in open terrain and urban (non-vegetated) areas. The control points were distributed throughout the project area and were surveyed using GPS techniques. See survey report for additional survey methodologies. Elevations from the unclassified lidar surface were measured for the x,y location of each control point. Elevations interpolated from the lidar surface were then compared to the elevation values of the surveyed control points. AccuracyZ has been tested to meet 0.643 ft or better Vertical Accuracy at 95% confidence level using RMSE(z) x 1.9600 as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASRPS Guidelines. Tested 0.216 feet at a 95% confidence level (or 3.5 cm RMSE) using RMSE(z) x 1.9600 as defined by the National Standards for Spatial Data Accuracy (NSSDA). The Vertical Accuracy of the classified lidar point cloud swath files was calculated against TINs derived from the final calibrated and controlled swath data using 20 control points located in Open Terrain and Urban land cover classes. |
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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 Vertical Accuracy specifications. |
Conceptual Consistency: |
Data covers the entire area specified for this project. |
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
Lineage Statement: |
This data was provided by Mass GIS to the NOAA OCM for custom distribution by the NOAA Digital Coast Data Access Viewer (DAV) and bulk distribution via S3 AWS service. |
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Sources
Lidar Point Cloud
Contact Role Type: | Originator |
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Contact Type: | Organization |
Contact Name: | Mass GIS |
Citation URL: | https://www.mass.gov/orgs/massgis-bureau-of-geographic-information |
Citation URL Name: | Mass GIS |
Process Steps
Process Step 1
Description: |
The following steps describe the Raw Data Processing and Calibration process: 1) Technicians processed the raw data to LAS format flight lines using the ABGNSS/IMU solution. 2) Technicians use TerraSolid TerraMatch to calculate initial calibration adjustment angles by mission and/or block. This is accomplished by identifying ground and above ground feature observations between flight-lines and calculating the offsets. The technician then analyzed the results and made any necessary additional adjustment until it is acceptable. 3) Once the angle calculation was completed the adjusted settings were applied to all of the flight-lines of the mission and/or block and checked for consistency. The technicians utilized commercial and proprietary software packages to analyze how well flight-line overlaps match and adjusted as necessary until the results met the project specifications. 4) 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 less than or equal to 6 cm RMSEz within individual swaths and less than or equal to 8 cm RMSDz or within swath overlap (between adjacent swaths). 5) The technicians ran a final vertical accuracy check of the calibrated point cloud against the surveyed check points after the z correction to ensure the requirement of NVA = 19.6 cm 95% Confidence Level (Required Accuracy) was met. Point classification was performed according to USGS Lidar Base Specification 1.2, and breaklines were collected for water features. Bare earth DEMs were exported from the classified point cloud using collected breaklines for hydroflattening. |
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Process Date/Time: | 2018-01-01 00:00:00 |
Process Step 2
Description: |
LAS Point Classification: The point classification is performed as described below. The bare-earth surface is manually reviewed to ensure correct classification on the Class 2 (Ground) points. After the bare-earth surface is edited and QC'd, it is then used to generate all hydro-breaklines through heads-up digitization. All ground (ASPRS Class 2) lidar data inside of the Lake Pond and River Pond hydro flattening breaklines were then classified to water (ASPRS Class 9) using LP360 functionality. A buffer of 0.5 meters was also used around each hydro-flattened feature to classify these ground (ASPRS Class 2) points to Ignored ground (ASPRS Class 10). All Lake Pond Island and River Stream Island features were checked to ensure that the ground (ASPRS Class 2) points were reclassified to the correct classification after the automated classification was completed. All overlap data was processed through automated functionality provided by TerraScan to classify the overlapping flight-line data to approved classes by USGS. The overlap data was classified using standard LAS overlap bit. These classes were created through automated processes only and were not verified for classification accuracy. All data was manually reviewed and any remaining artifacts removed using functionality provided by TerraScan and TerraModeler. Global Mapper is used as a final check of the bare-earth dataset. GeoCue was then used to create the deliverable industry-standard LAS files for the Classified Point Cloud Data. LAStools, LP360 and TerraScan software was used to perform statistical analysis of the classes in the LAS files, on a per tile level to verify classification metrics and full LAS header information. |
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Process Date/Time: | 2018-10-12 00:00:00 |
Process Step 3
Description: |
The NOAA Office for Coastal Management (OCM) was provided this data set from the office of Mass GIS. The total number of files received and processed was 1577. The data were in Massachusetts Island State Plane (NAD83 2011), US survey feet coordinates and NAVD88 (Geoid12B) elevations in feet. The data were classified as: 1 - Unclassified, 2 - Ground, 7 - Low Noise, 9 - Water, 10 - Ignored Ground, 17 - Bridge Deck, 18 - High Noise. OCM processed all classifications of points to the Digital Coast Data Access Viewer (DAV). Classes available in the DAV are: 1, 2, 7, 9, 10, 17, 18. OCM performed the following processing on the data for Digital Coast storage and provisioning purposes: 1. An internal OCM script was run to check the number of points by classification and by flight ID and the gps and intensity ranges. 2. Internal OCM scripts were run on the laz files to convert from orthometric (NAVD88) elevations to ellipsoid elevations using the Geoid12B model, to convert from Massachusetts Island State Plane (NAD83 2011), US survey feet coordinates to geographic coordinates, to convert from elevations in feet to meters, to assign the geokeys, to sort the data by gps time and zip the data to database and to the Amazon S3 bucket. |
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Process Date/Time: | 2022-06-29 00:00:00 |
Process Contact: | Office for Coastal Management (OCM) |
Related Items
Item Type | Relationship Type | Title |
---|---|---|
Data Set (DS) | Cross Reference |
2018 Town of Nantucket Lidar DEM: Nantucket Island, MA |
Catalog Details
Catalog Item ID: | 67485 |
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GUID: | gov.noaa.nmfs.inport:67485 |
Metadata Record Created By: | Rebecca Mataosky |
Metadata Record Created: | 2022-06-29 17:12+0000 |
Metadata Record Last Modified By: | SysAdmin InPortAdmin |
Metadata Record Last Modified: | 2023-10-17 16:12+0000 |
Metadata Record Published: | 2022-06-30 |
Owner Org: | OCMP |
Metadata Publication Status: | Published Externally |
Do Not Publish?: | N |
Metadata Last Review Date: | 2022-06-30 |
Metadata Review Frequency: | 1 Year |
Metadata Next Review Date: | 2023-06-30 |