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Short Citation:
OCM Partners, 2022: 2004 Maryland Department of Natural Resources LiDAR: Anne Arundel, Charles, Howard and St. Mary's Counties, https://www.fisheries.noaa.gov/inport/item/49782.

Item Identification

Title: 2004 Maryland Department of Natural Resources LiDAR: Anne Arundel, Charles, Howard and St. Mary's Counties
Short Name: md2004_m27_metadata
Status: Completed
Publication Date: 2005-01-20
Abstract:

Light Detection and Ranging (LIDAR) is a method of locating objects on the ground using aerial-borne equipment. It is similar

to RADAR or SONAR in that the two-way travel time of an energy beam reflected off an object is precisely measured, but this technology

uses laser light instead of radio or sound waves. This technology has proven very useful in remote sensing of the earth. It can be used

for determining elevations of both the earth's surface and items (natural and man-made) on the surface. Analysis of LIDAR data is used

in detailed modeling of the earth's surface for drainage and floodplain studies, determining how a new structure will affect views from

various locations, shoreline erosion studies, and other reasons. This data set contains only the bare earth mass points. Bare earth

points represent ground features. Features that are above ground, such as buildings, bridges, tree tops, etc, have been eliminated.

Mass points may appear to have "holes" with no elevation values in areas where the surface could not be determined, such as very dense

forests or urban areas.

Original contact information:

Contact Name: Ken Miller

Contact Org: Maryland Department of Natural Resources

Title: Chief. Watershed Information Services Division

Phone: 410-260-8751

Email: kenmiller@dnr.state.md.us

Purpose:

The LIDAR-derived data were collected by the Maryland Department of Natural Resources in support of shore erosion studies along

the shorelines of the Chesapeake Bay. It also supports the Federal Emergency Management Agency's specifications for mapping floodplains.

These efforts required detailed elevation data and models, such as those available from LIDAR sensing. The data have also been made

available to aid in other projects that require detailed surface, vegetation and/or structure elevations.

Notes:

10426

Other Citation Details:

1. The Sanborn Map Company, Inc. (flight firm)

2. Computational Consulting Services, LLC (processing firm)

3. Spatial Systems Associates, Inc. (post-processing firm)

4. Dewberry and Davis (QA/QC firm)

Supplemental Information:

These data are part of a suite of spatial data products generated using the LIDAR technology. First and Last

returns are generated. From these data, Bare-Earth Mass Points that represent the earths surface are produced. A gridded Digital

Elevation Model (DEM) is produced from the Bare Earth Mass Points. Imagery is also created that represents the intensity of the LIDAR

return; it is a 1-meter resolution product that resembles a panchromatic Digital Orthophoto Quad (DOQ).

The Anne Arundel/Howard Counties and Charles/StMarys Counties, Maryland QA Reports may be viewed at:

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/27/supplemental/index.html

Keywords

Theme Keywords

Thesaurus Keyword
ISO 19115 Topic Category
elevation
UNCONTROLLED
DNR General Bald earth
DNR General Bare earth
DNR General Bathymetry/Topography
DNR General DEM
DNR General Digital Elevation Model
DNR General DNR
DNR General Elevation and derived products
DNR General Elevation model
DNR General First return
DNR General Gridded DEM
DNR General Last return
DNR General LIDAR
DNR General Surface model
DNR General Terrain model

Physical Location

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

Data Set Information

Data Set Scope Code: Data Set
Maintenance Frequency: None Planned
Distribution Liability:

Any conclusions drawn from the analysis of this information are not the responsibility of NOAA, the OCM or its partners.

Data Set Credit: Spatial Systems Associates, Inc. was the prime contractor for this project. It partnered with Sanborn Map Company, Inc., Computational Consulting Services, Inc., NXL Construction Services, Inc and Dewberry LLC. Charles County participated with DNR and its vendor.

Support Roles

Data Steward

CC ID: 676944
Date Effective From: 2005-01-20
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: 676946
Date Effective From: 2005-01-20
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: 676947
Date Effective From: 2005-01-20
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: 676945
Date Effective From: 2005-01-20
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: 1135278
W° Bound: -76.472538
E° Bound: -75.297853
N° Bound: 39.124828
S° Bound: 37.881527

Extent Group 1 / Time Frame 1

CC ID: 1135277
Time Frame Type: Range
Start: 2004-04
End: 2004-05

Spatial Information

Spatial Representation

Representations Used

Vector: Yes

Access Information

Security Class: Unclassified
Data Access Procedure:

This data set can be obtained online at the following URL: https://coast.noaa.gov/dataviewer;

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. The Department of Natural Resources makes no warranty, expressed or implied, as to the use or appropriateness of Spatial

Data, and there are no warranties of merchantability or fitness for a particular purpose or use. The information contained in Spatial Data

is from publicly available sources, but no representation is made as to the accuracy or completeness of Spatial Data. The Department of

Natural Resources shall not be subject to liability for human error, error due to software conversion, defect, or failure of machines,

or any material used in the connection with the machines, including tapes, disks, CD-ROMs or DVD-ROMs and energy. The Department of Natural

Resources shall not be liable for any lost profits, consequential damages, or claims against the Department of Natural Resources by third

parties. The liability of the Department of Natural Resources for damage regardless of the form of the action shall not exceed any

distribution fees that may have been paid in obtaining Spatial Data.

Distribution Information

Distribution 1

CC ID: 741312
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=27
Distributor:
File Name: Customized Download
Description:

Create custom data files by choosing data area, product type, map projection, file format, datum, etc.

Distribution 2

CC ID: 741313
Download URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/27/index.html
Distributor:
File Name: Bulk Download
Description:

Simple download of data files.

Activity Log

Activity Log 1

CC ID: 676974
Activity Date/Time: 2016-05-23
Description:

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 676973
Activity Date/Time: 2017-11-14
Description:

Converted from FGDC Content Standards for Digital Geospatial Metadata (version FGDC-STD-001-1998) using 'fgdc_to_inport_xml.pl' script. Contact Tyler Christensen (NOS) for details.

Activity Log 3

CC ID: 718351
Activity Date/Time: 2018-02-08
Description:

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 741314
Activity Date/Time: 2018-03-13
Description:

Partial upload to move data access links to Distribution Info.

Technical Environment

Description:

A variety of specialized hardware and software platforms were used to collect, process and quality assess

these data. Typically, Intel machines running Microsoft Windows 2000 Version 5.0 (Build 2195) Service Pack 4.

Data Quality

Accuracy:

There are four (4) attributes in the Bare Earth Mass Points files, representing the horizontal coordinates

(easting and northing) and vertical position observed and vertical assigned (see process description). Random inspections were made to

assure that each line in the file contained 4 values.

Horizontal Positional Accuracy:

The horizontal coordinate values were designed to meet NSSDA accuracy for data at 1:2400 scale.

Vertical Positional Accuracy:

The RMSE value of 14.3 cm at the 95% confidence level was determined by an independent accuracy

assessment conducted by Dewberry LLC according to the contract specifications. These specifications followed FEMA Appendix A guidelines

regarding assessing vertical accuracy. For data accurate to within 18.5 cm RMSE, the guidelines recommended a minimum of 20 independent

check points be located in each of 5 different land cover categories: Grass/Ground, High Grass/Crops, Brush/Low Trees, Forest, and

Urban/Pavement. A total of 125 points were used for the assessments. These points were surveyed by a licensed land surveyor and

provided a positional location and elevation with an accuracy that exceeded the predicted accuracy of the LIDAR data. The entire

accuracy reports can be found at http://dnrweb.dnr.state.md.us/gis/data/lidar.

; Quantitative Value: 0.143 meters, Test that produced the value:

The RMSE value is 14.3 cm. See the Vertical Positional Accuracy Report section for more

information.

Completeness Measure:

Cloud Cover: 0

Completeness Report:

Spatial Systems Associates performed various inspections of the data to ensure: that each file contained the points

located within that tile; that tiles were completely filled; that the point density per tile was within expected ranges, and that the

tiles were correctly named.

Conceptual Consistency:

Computational Consulting Services, the LIDAR processing vendor used proprietary algorithms to remove features

and artifacts in the First and Last Return data that did not reflect true ground elevation. Subsequent quality assurance testing by

Dewberry determined that the data met FEMA and MD DNR specifications for both vertical accuracy and other consistencies with accepted

standards. The QA report can be accessed at http://dnrweb.dnr.state.md.us/gis/data/lidar.

Lineage

Process Steps

Process Step 1

CC ID: 1135270
Description:

LIDAR Data Acquisition. The Sanborn Map Company, Inc. flew the project area with the LIDAR sensor. Where overlaps

between the two series of data occurred, the newer data was used. No attempt at blending the two datasets was made to maintain the

highest data integrity. In an effort to permit correlation of the point values with tidal gauge stations, the Sanborn Map Company,

Inc. was required to fly tidal shoreline areas during the low tide cycle (slack water - low tide - slack water) as predicted by local

tide stations. The LIDAR sensor collected raw data that was referenced in UTM. The flight plan on this project included the following

specifications to meet the project requirements: *Single pass density - 1.696 square meters per sample; *Average area sampling

density -1.272 square meters per sample; *Swath width - 996.76 meters; *Flight altitude -1371 meters (4500 ft); *Flight line

spacing - 498.38 meters w/50% overlap; *Scan frequency - 21 Hz; *Firing rate - 25 kHz; *Scan angle - 20 degrees; *Ground speed - 140

knots. When complete, the raw data was delivered to Spatial Systems.

Process Step 2

CC ID: 1135271
Description:

LIDAR Data Processing. Computational Consulting Systems. The First and Last Return data was delivered to CCS in

large blocks of data. CCS processed the data using both the First and Last Returns, removed artifacts using automated and manual

techniques, and reprojected the data into the client-specified X, Y, Z text files using the 1200 meter x 1800 meter tiles, NAD 83

meters, NAVD 88 meters. CCS also generated the Intensity Imagery using the client-specified USGS 3.75' tiling scheme. The data products

were delivered to SSA for quality assurance testing, formatting and final delivery.

Process Step 3

CC ID: 1135272
Description:

LIDAR Data Post Processing. Spatial Systems Associates. SSA digitized the shoreline from the Intensity Imagery

for the purposes of delineating a shoreline. Any LIDAR points that fell seaward of this shoreline were assigned the value of zero (0).

In addition to the shoreline, SSA delineated upland ponds using the same technique and assigned all LIDAR points that fell within the

water area the value of the lowest observed point close to the shore. The observed elevation values were not lost - a fourth field

in the data file was added for the assigned value. SSA also performed a variety of QA procedures to determine if the point density

was within expected ranges; that each tile was completely filled; that all tiles were accounted for, and that the tiles were named

in accordance with client specifications.

Process Step 4

CC ID: 1135273
Description:

LIDAR Data Check Point Surveys. NXL Construction Services. NXL was contracted to acquire the check-points in the

5 different land cover classes. SSA provided NXL with maps of each area where a check-point was to be located. The points were scattered

throughout the project area. NXL was permitted the latitude to select the exact location based on field conditions, provided the points

were generally within a 1 mile radius of the chosen location and that the land cover class was the same as the one specified. The land

cover classes were: Grass/Ground, High Grass/Crops, Brush/Low Trees, Forest, and Urban/Pavement.

Process Step 5

CC ID: 1135274
Description:

LIDAR Data Quality Assurance. Dewberry LLC was provided with the check-point and LIDAR Bare Earth Mass Points

data to perform their independent quality assurance work. They performed detailed analyses to determine if the vertical accuracy

was within specifications and examined the data for flight, data collection and processing inconsistencies. Neither the flight vendor

(Airborne 1) nor the processing vendor (CCS) was given access to the check-point data. The entire accuracy report can be found at

http://dnrweb.dnr.state.md.us/gis/data/lidar.

Process Step 6

CC ID: 1135275
Description:

The NOAA Office for Coastal Management (OCM) received LAS files containing the point cloud elevation data from Earth

Data, Inc. OCM performed the following processing on the data to make it available within the Lidar Data Retrieval Tool (LDART):

1. Variable length header records were added to the LAS files to identify projection, datum and sort order.

2. The LFIT (LDART formatted binary) files were sorted by latitude.

3. LFIT files were converted to xyz format ASCII files.

Process Date/Time: 2005-01-01 00:00:00

Catalog Details

Catalog Item ID: 49782
GUID: gov.noaa.nmfs.inport:49782
Metadata Record Created By: Anne Ball
Metadata Record Created: 2017-11-15 15:22+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2022-08-09 17:11+0000
Metadata Record Published: 2022-03-16
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