49781
2003 Maryland Department of Natural Resources LiDAR: Dorchester, Somerset, Talbot,and Wicomico Counties, with portions of Caroline, Kent and Queen Anne's Counties
md2003_m16_metadata
Data Set
Published / External
49401
Lidar - partner (no harvest)
Project
Completed
2006-10-18
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 Org: NOAA Office for Coastal Management
Phone: 843-740-1202
Email: coastal.info@noaa.gov
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.
10425
1. Airborne 1 (flight firm)
2. Computational Consulting Services, LLC (processing firm)
3. Spatial Systems Associates, Inc. (post-processing firm)
4. Dewberry & Davis (QA/QC firm)
5. Maryland Department of Natural Resources
The Dorchester, Somerset, Talbot, and Wicomico Counties, Maryland QA Report may be viewed at:
https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/16/supplemental/index.html
Theme
ISO 19115 Topic Category
elevation
Theme
Mass points
Office for Coastal Management
Charleston
SC
Data Set
None Planned
Any conclusions drawn from the analysis of this information are not the responsibility of NOAA, the Office for Coastal Management or its partners.
The 2003 Maryland LIDAR data were collected for the Maryland Department of Natural Resources. Spatial Systems Associates,
Inc. was the prime contractor for this project. It partnered with Airborne 1 Corporation, Computational Consulting Services, Inc., NXL
Construction Services, Inc and Dewberry LLC. The following organizations participated with DNR and its vendor in funding the collecting
and processing of the LIDAR data. They are: City of Salisbury, Salisbury University, University of Maryland, Dorchester County, Talbot
County and the National Ocean and Atmospheric Administration's (NOAA) Office for Coastal Management (OCM).
Data Steward
2006-10-18
Organization
NOAA Office for Coastal Management
NOAA/OCM
coastal.info@noaa.gov
2234 South Hobson Ave
Charleston
SC
29405-2413
(843) 740-1202
https://coast.noaa.gov
NOAA Office for Coastal Management Home Page
Online Resource
Distributor
2006-10-18
Organization
NOAA Office for Coastal Management
NOAA/OCM
coastal.info@noaa.gov
2234 South Hobson Ave
Charleston
SC
29405-2413
(843) 740-1202
https://coast.noaa.gov
NOAA Office for Coastal Management Home Page
Online Resource
Metadata Contact
2006-10-18
Organization
NOAA Office for Coastal Management
NOAA/OCM
coastal.info@noaa.gov
2234 South Hobson Ave
Charleston
SC
29405-2413
(843) 740-1202
https://coast.noaa.gov
NOAA Office for Coastal Management Home Page
Online Resource
Point of Contact
2006-10-18
Organization
NOAA Office for Coastal Management
NOAA/OCM
coastal.info@noaa.gov
2234 South Hobson Ave
Charleston
SC
29405-2413
(843) 740-1202
https://coast.noaa.gov
NOAA Office for Coastal Management Home Page
Online Resource
Ground Condition
-76.384067
-75.354478
39.123691
37.888026
Range
2003-03-01
2003-11-30
Yes
Unclassified
This data can be obtained on-line at the following URL: https://coast.noaa.gov/dataviewer;
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. The NOAA and 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.
https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=16
Customized Download
Create custom data files by choosing data area, product type, map projection, file format, datum, etc.
https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/16/index.html
Bulk Download
Simple download of data files.
2016-05-23
Date that the source FGDC record was last modified.
2017-11-14
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.
2018-02-08
Partial upload of Positional Accuracy fields only.
2018-03-13
Partial upload to move data access links to Distribution Info.
None available
The horizontal coordinate values were designed to meet NSSDA accuracy for data at 1:2400 scale.
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: 14.3 meters, Test that produced the value:
The RMSE value is 14.3 cm. See the Vertical Positional Accuracy Report section for more
information.
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.
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.
Elevation Data - LiDAR Bare Earth Mass Points
2004-03-20
Range
2003-03-01
2003-11-30
Bare-earth LIDAR x-y-z-i data files | Type of Source Media: Disc
1
LIDAR Data Acquisition. Airborne 1, using an Optec 25 MHz system, flew the project area with the LIDAR sensor.
A portion of the 2003 project area included data acquisition of portions of the LIDAR 2002 project area that had incomplete coverage.
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 Airborne 1
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 specifications called for data collection during leaf-off
conditions, which generally run through early to mid April. However, due to late winter snow cover, windy flight conditions and other
technical obstacles, data acquisitions continued into early June 2003. In addition, a small area in the north end of the project area
was acquired in July. Anticipating the trouble with leaf density, Airborne 1 modified the flight parameters to increase the laser
light penetration to the ground. 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.
2004-01-20T00:00:00
2
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.
2004-01-20T00:00:00
3
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.
2004-01-20T00:00:00
4
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.
2004-01-20T00:00:00
5
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 with 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.
2004-01-20T00:00:00
6
The NOAA Office for Coastal Management (OCM) received ASCII files containing the bare-earth elevation and intensity
data from Maryland Department of Natural Resources. OCM performed the following processing on the data to make it available within
the Lidar Data Retrieval Tool (LDART):
1. The data were projected from Maryland State Plane coordinates to geographic decimal degrees using the General Cartographic
Transformation Package.
2. The lat, long, MODZVAL and intensity values where extracted from the ASCII files and converted to the LDART binary format.
3. The data were converted to xyz text files
2004-05-28T00:00:00
gov.noaa.nmfs.inport:49781
Anne Ball
2017-11-15T15:22:16
SysAdmin InPortAdmin
2022-08-09T17:11:36
2022-03-16
OCM Partners
OCMP
1002
Public
No
2022-03-16
1 Year
2023-03-16