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Short Citation:
OCM Partners, 2024: 2017 Lidar (0.5 m) DEM: Eastern Maine - Merrymeeting Bay, https://www.fisheries.noaa.gov/inport/item/57187.

Item Identification

Title: 2017 Lidar (0.5 m) DEM: Eastern Maine - Merrymeeting Bay
Short Name: me2017_mmtg_0.5_dem_m8808_metadata
Status: Completed
Creation Date: 2019-08-09
Publication Date: 2018-03-30
Abstract:

A separate, specific metadata record was not provided for this data set, so the DEM metadata record for the larger data collection, 2017 Lidar DEM: Eastern Maine was used. Where available, information specific to this smaller collection has been included.

The NOAA Office for Coastal Management (OCM) received 19 DEM files from the State of Maine. OCM processed the data to be available on the Digital Coast Data Access Viewer (DAV) and for bulk download.

This 0.5 m DEM covers a small area in southern Maine. The lidar data was collected at the same time as a much larger data set in eastern Maine, but was provided at 8 points per square meter. A 0.25 m resolution DEM is also available for the same area. See the Related Items section of this metadata record for a link to that data set metadata record.

In addition to these bare earth Digital Elevation Model (DEM) data, the lidar point data that these DEM data were created from, are also available. A link to the metadata record for this data set is provided in the Related Items section. Additionally, the hydro breaklines are available. See the URL section of this metadata record for a link to the hydro breaklines.

Product: These are Digital Elevation Model (DEM) data for the Maine 2017 LiDAR QL2 - Delivery #2 area in Aroostook, Hancock, Penobscot, Piscataquis, Sagadahoc, Somerset, and Washington Counties, Maine as part of the required deliverables for the 2017 Maine LiDAR project. Class 2 (ground) lidar points in conjunction with the hydro breaklines were used to create 0.25-meter, 0.5-meter, and 1-meter hydro-flattened raster DEMs.

Geographic Extent: Merrymeeting Bay, ME in Sagadahoc County, covering approximately 2 square miles.

Maine 2017 LiDAR 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 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base LiDAR Specification, Version 1.2. The data for counties in the eastern AOI was developed based on a horizontal projection/datum of NAD83 (2011) UTM Zone 19, meters and vertical datum of NAVD88 (GEOID12B), meters. LiDAR data was delivered as flightline-extent unclassified LAS swaths, as processed Classified LAS 1.4 files formatted to 11,133 individual 1,500-meter x 1,500-meter tiles, 63 individual 750-meter x 750-meter tiles, and 36 individual 500-meter x 500-meter tiles, as tiled intensity imagery, and as tiled bare earth DEMs; all tiled to the same 1,500-meter x 1,500-meter schema. Continuous hydro-flattened breaklines were produced in Esri file geodatabase format.

Ground Conditions: LiDAR was collected in the spring and fall of 2017, 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, Quantum Spatial, Inc. established a total of 181 ground control points that were used to calibrate the LiDAR to known ground locations established throughout the project area. An additional 301 independent accuracy checkpoints, 178 in Bare Earth and Urban landcovers (178 NVA points), 123 in Forested, Shrubs, and Tall Weeds categories (123 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data.

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 DEMs. The purpose of these LiDAR data was to produce high accuracy 3D hydro-flattened digital elevation models (DEMs) with a 1-meter 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:

Raster File Type = IMG

Bit Depth/Pixel Type = 32-bit float

Raster Cell Size = 0.5 Meter

Interpolation or Resampling Technique = Triangulated Irregular Network (TIN), Linear Interpolation, Proprietary

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
UNCONTROLLED
None DEM

Spatial Keywords

Thesaurus Keyword
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

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
Global Change Master Directory (GCMD) Platform Keywords
DEM > Digital Elevation Model

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: Raster digital data
Distribution Liability:

In no event shall the creators, custodians, or distributors of these data be liable for any damages arising out of its use, or from the inability of the customer to use these data for their intended application.

Any conclusions drawn from the analysis of this information are not the responsibility of the State of Maine, NOAA, the Office for Coastal Management or its partners.

Data Set Credit: Quantum Spatial, Inc.

Support Roles

Data Steward

CC ID: 867973
Date Effective From: 2019
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: 867972
Date Effective From: 2019
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: 867974
Date Effective From: 2019
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: 867975
Date Effective From: 2019
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: 1292330
W° Bound: -69.901956
E° Bound: -69.867084
N° Bound: 44.004341
S° Bound: 43.951092

Extent Group 1 / Time Frame 1

CC ID: 1292329
Time Frame Type: Discrete
Start: 2017-04-30

Spatial Information

Reference Systems

Reference System 1

CC ID: 1292327

Coordinate Reference System

CRS Type: Projected
EPSG Code: EPSG:6348
EPSG Name: NAD83(2011) / UTM zone 19N
See Full Coordinate Reference System Information

Access Information

Security Class: Unclassified
Data Access Procedure:

Data are 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: 867979
Start Date: 2019-08-09
End Date: Present
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=8808
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2019 - Present)
File Name: Customized Download
Description:

Create custom data files by choosing data area, map projection, file format, etc. A new metadata will be produced to reflect your request using this record as a base.

File Type (Deprecated): Zip
Compression: Zip

Distribution 2

CC ID: 867980
Start Date: 2019-08-09
End Date: Present
Download URL: https://noaa-nos-coastal-lidar-pds.s3.us-east-1.amazonaws.com/dem/ME_Merrymtg_0.5_DEM_2017_8808/index.html
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2019 - Present)
File Name: Bulk Download
Description:

Bulk download of data files in the original coordinate system.

File Type (Deprecated): GeoTIFF
Distribution Format: GeoTIFF

URLs

URL 1

CC ID: 867965
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: 867966
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: 867967
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid12b/8772/supplemental/me2017_mmtgbay_8ppsm_m8772.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: 867968
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid12b/8772/supplemental/FOCUSonAcc_Maine_2017_LiDAR_20180424_115518.pdf
Name: Dataset report
URL Type:
Online Resource
File Resource Format: PDF
Description:

Link to data set report.

URL 5

CC ID: 867969
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid12b/8772/supplemental/Final_Maine_Survey_Report.pdf
Name: Dataset report
URL Type:
Online Resource
File Resource Format: PDF
Description:

Link to data set report.

URL 6

CC ID: 867970
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid12b/8772/supplemental/Maine_2017_LiDAR_FOCUS_Report.pdf
Name: Dataset report
URL Type:
Online Resource
File Resource Format: PDF
Description:

Link to data set report.

URL 7

CC ID: 867971
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid12b/8772/supplemental/Maine_ProjectReport_Deliverable.pdf
Name: Dataset report
URL Type:
Online Resource
File Resource Format: PDF
Description:

Link to data set report.

URL 8

CC ID: 868008
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid12b/8772/breaklines/
URL Type:
Online Resource
Description:

Link to the hydro breaklines.

Data Quality

Vertical Positional Accuracy:

The project specifications require the accuracy (ACCz) of the derived DEM be calculated and reported in two ways:

1. The required NVA is: 19.6 cm at a 95% confidence level, derived according to the ASPRS Positional Accuracy Standards for Geospatial Data, i.e., based on RMSE of 10 cm in the "bare earth" and "urban" land cover classes. This is a required accuracy. The NVA was tested with 178 checkpoints located in bare earth and urban (non-vegetated) areas.

2. Vegetated Vertical Accuracy (VVA): VVA shall be reported for "forested", "shrubs", and "tall weeds" land cover classes. The target VVA is: 29.4 cm at the 95th percentile, derived according to ASPRS Guidelines, Vertical Accuracy Reporting for LiDAR Data, i.e., based on the 95th percentile error in all vegetated land cover classes combined. This is a target accuracy.

The VVA was tested with 123 checkpoints located in forested, shrubs, and tall weeds (vegetated) areas. The checkpoints were distributed throughout the project area and were surveyed using GPS techniques. See survey report for additional survey methodologies. AccuracyZ has been tested to meet 19.6 cm or better Non-Vegetated Vertical Accuracy at 95% confidence level using RMSE(z) x 1.9600 as defined by the ASPRS Positional Accuracy Standards for Geospatial Data; assessed and reported using National Digital Elevation Program (NDEP)/ASRPS Guidelines.This data set was tested to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 10 cm RMSEz Vertical Accuracy Class.

Actual NVA accuracy was found to be RMSEz = 5.1 cm, equating to 9.9 cm at 95% confidence level. The NVA of the DEM was calculated using 178 independent checkpoints located in the Bare Earth and Urban land cover categories. This data set was tested to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 10 cm RMSEz Vertical Accuracy Class.

Actual NVA accuracy was found to be RMSEz = 5.1 cm, equating to 9.9 cm at 95% confidence level. Actual VVA accuracy was found to be 25.5 cm at the 95th percentile. VVA was calculated using 123 checkpoints located in the Forested, Shrubs, and Tall Weeds land cover categories at the 95th percentile, derived according to ASPRS Guidelines, Vertical Accuracy Reporting for LiDAR Data. Tested against the DEM.

Completeness Report:

Datasets contain complete coverage of tiles. No points have been removed or excluded. A visual qualitative assessment was performed to ensure data completeness. There are no void areas or missing data. The raw point cloud is of good quality and data passes Non-Vegetated Vertical Accuracy specifications.

Conceptual Consistency:

Data covers the entire area specified for this project.

Lineage

Process Steps

Process Step 1

CC ID: 1292325
Description:

Hydro-Flattened Raster DEM Processing: Class 2 (Ground) LiDAR points in conjunction with the hydro-breaklines were used to create a 1-meter hydro-flattened raster DEM. Using proprietary QSI software, an ERDAS Imagine .IMG file was created for each tile using a linear interpolation method. Each surface is reviewed using Global Mapper to check for any surface anomalies or incorrect elevations found within the surface.

Process Date/Time: 2017-01-01 00:00:00

Process Step 2

CC ID: 1292326
Description:

The NOAA Office for Coastal Management (OCM) received 19 raster DEM img format files from the State of Maine GIS. The data were in UTM Zone 19 NAD83(2011) meters coordinates and NAVD88 (Geoid12b) elevations in meters. The DEMs are at 0.5 m grid spacing. A separate, specific metadata record was not provided for this data set, so the DEM metadata record for the larger data collection, 2017 Lidar DEM: Eastern Maine was used. Where available, information specific to this smaller collection has been included. OCM did the following processing to the data for Digital Coast storage and provisioning purposes:

1. Converted the files from img format to tif format using gdal_translate

2. Assigned EPSG codes using gdal_translate

3. Copied the files to https

Process Date/Time: 2019-08-09 00:00:00
Process Contact: Office for Coastal Management (OCM)

Related Items

Item Type Relationship Type Title
Data Set (DS) Cross Reference 2017 Lidar (8 PPSM): Eastern Maine - Merrymeeting Bay

Catalog Details

Catalog Item ID: 57187
GUID: gov.noaa.nmfs.inport:57187
Metadata Record Created By: Rebecca Mataosky
Metadata Record Created: 2019-08-09 10:58+0000
Metadata Record Last Modified By: Kirk Waters
Metadata Record Last Modified: 2024-01-10 19:06+0000
Metadata Record Published: 2024-01-10
Owner Org: OCMP
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