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Short Citation:
OCM Partners, 2022: 2006 Maryland Department of Natural Resources Lidar: Caroline, Kent and Queen Anne Counties, https://www.fisheries.noaa.gov/inport/item/49784.

Item Identification

Title: 2006 Maryland Department of Natural Resources Lidar: Caroline, Kent and Queen Anne Counties
Short Name: md2006_m103_metadata
Status: Completed
Publication Date: 2006-10-05
Abstract:

Maryland Department of Natural Resources requested the collection of LIDAR data over Kent, Queen Anne and

Caroline Counties, MD. In response, EarthData acquired the data from March 18 through April 6, 2006.

Airborne lidar data was acquired at an altitude of 5,500'(1676.4 m) above mean terrain with a swath width of 40 degrees,

which yields an average post spacing of lidar points of no greater than 6.56 ft (2 m). The project was designed to

achieve a vertical accuracy of the lidar points at 7.09 in (18 cm) root mean square error (RMSE). The flight design

included a total of seventy-seven flight lines with approximately 2,246 total line miles (3614.59 km). The lidar

data was acquired prior to the emergence of deciduous foliage. This is a bare earth data set.

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. "First returns" are the first elevation value that the LiDAR sensor recorded for a given x,y coordinate.

Likewise, "last returns" are the last elevation value that the LiDAR sensor recorded for a given x,y coordinate.

The Bare Earth Mass Points are point elevations that represent the "bare earth." Features that are above the

ground - such as buildings, bridges, tree tops, etc. - are not included in these data.

The Gridded DEM is a model of the surface of the earth (no above-surface features such as buildings, tree tops, etc)

with a point at every 2 meters representing the average surface elevation of that area.

The LIDAR Intensity Imagery are similar to aerial photography. While not as sharp as traditional aerial photos,

they offer a good visual representation of the surface and various features.

Original contact information:

Contact Name: Kevin Boone

Contact Org: Maryland Department of Natural Resources

Title: Chief GIS Officer

Phone: 410-260-8753

Email: kboone@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:

10428

Supplemental Information:

The Lidar QA/QC Assessment Report for Maryland Department of Natural Resources for Caroline,

Kent and Queen Anne Counties may be viewed at:

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/103/supplemental/MD_DNR_LIDAR_QA_Report_2006_caro_kent_queen.pdf

Keywords

Theme Keywords

Thesaurus Keyword
ISO 19115 Topic Category
elevation
UNCONTROLLED
None ASCII
None Bare earth
None Intensity image

Physical Location

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

Data Set Information

Data Set Scope Code: Data Set
Maintenance Frequency: Unknown
Distribution Liability:

Any conclusions drawn for the analysis of this information are not the responsibility of the Maryland

Department of Natural Resources, the Office for Coastal Management, or its partners.

Support Roles

Data Steward

CC ID: 677027
Date Effective From: 2006-10-05
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: 677029
Date Effective From: 2006-10-05
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: 677030
Date Effective From: 2006-10-05
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: 677028
Date Effective From: 2006-10-05
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: 1132252
W° Bound: -76.300698
E° Bound: -75.688478
N° Bound: 39.383359
S° Bound: 38.729653

Extent Group 1 / Time Frame 1

CC ID: 1132251
Time Frame Type: Range
Start: 2006-03-18
End: 2006-04-06

Spatial Information

Spatial Representation

Representations Used

Vector: Yes

Access Information

Security Class: Unclassified
Data Access Procedure:

This data can be obtained on-line 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.

Distribution Information

Distribution 1

CC ID: 741318
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=103
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: 741319
Download URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/103/index.html
Distributor:
File Name: Bulk Download
Description:

Simple download of data files.

URLs

URL 1

CC ID: 741321
URL: https://coast.noaa.gov/dataviewer
URL Type:
Online Resource

URL 2

CC ID: 741322
URL: https://coast.noaa.gov
URL Type:
Online Resource

Activity Log

Activity Log 1

CC ID: 677050
Activity Date/Time: 2016-05-23
Description:

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 677049
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: 718353
Activity Date/Time: 2018-02-08
Description:

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 741320
Activity Date/Time: 2018-03-13
Description:

Partial upload to move data access links to Distribution Info.

Data Quality

Accuracy:

Airborne lidar data was acquired at an altitude of 5,500'(1676.4 m) above mean terrain with a swath width of 40 degrees,

which yields an average post spacing of lidar points of no greater than 6.56 ft (2 m). The project was designed to

achieve a vertical accuracy of the lidar points at 7.09 in (18 cm) root mean square error (RMSE). The flight design

includes a total of seventy-seven flight lines with approximately 2,246 total line miles (3614.59 km). The lidar

data will be acquired prior to the emergence of deciduous foliage.

Horizontal Positional Accuracy:

The lidar data fully comply with FEMA guidance as published in Appendix A, April, 2003.

Vertical Positional Accuracy:

The lidar data fully comply with FEMA guidance as published in Appendix A, April 2003 and National

Standard for Spatial Accuracy (NSSDA). When compared to GPS survey grade points in generally flat non-vegetated

areas, at least 95% of the positions have an error less than or equal to 36.3 cm (equivalent to root mean square error of

18.5 cm if errors were normally distributed).

Completeness Measure:

Cloud Cover: 0

Completeness Report:

1. EarthData's proprietary software, Checkedb, for verification against ground survey points.

2. Terrascan, for verification of automated and manual editing and final QC of products.

Conceptual Consistency:

Compliance with the accuracy standard was ensured by the placement of GPS ground control prior to the

acquisition of lidar data. The following checks were performed:

1. The ground control and airborne GPS data stream were validated through a fully analytical boresight adjustment.

2. The DTM (Digital Terrain Model) data were checked against the project control.

3. Lidar elevation data was validated through an inspection of edge matching and visual inspection for

quality (artifact removal).

Lineage

Sources

Aerial Acquisition of Lidar Data for Kent, Queen Anne & Caroline Counties, MD

CC ID: 1132245
Publish Date: 2006-11-08
Extent Type: Range
Extent Start Date/Time: 2006-03-18
Extent End Date/Time: 2006-04-06
Source Contribution:

Maryland Department of Natural Resources requested the collection of LIDAR data over Kent, Queen Anne and

Caroline Counties, MD. In response EarthData acquired the data from March 18 through April 6, 2006 using its aircraft

with tail number N62912. LIDAR data was captured using an ALS50 LIDAR system, including an inertial

measuring unit (IMU) and a dual frequency GPS receiver. An additional GPS receiver was in constant operation over

a published control point set by EarthData at the base of operations airport which is a secondary Airport Control

Station. During the data acquisition, the receivers collected phase data at an epoch rate of 1 Hz. The use of the

Airport base station ensured that all data capture was performed within 50 miles of a base station. The solutions

from Kent, Queen Anne and Caroline counties were found to be of high integrity and met the accuracy requirements

for the project. These accuracy checks also verified that the data meets the guidelines outlined in FEMA's Guidelines

and Specifications for Flood Hazard Mapping Partners and Appendix 4B, Airborne Light Detection and Ranging

Systems.

Airspeed - 140 knots

Laser Pulse Rate - 52700 kHz

Field of View - 40 degrees

ScanRate - 30 Hz

| Source Geospatial Form: Model | Type of Source Media: Firewire Drive

Report of Survey for Caroline, Kent & Queen Anne's Counties

CC ID: 1132246
Publish Date: 2006-07-12
Extent Type: Discrete
Extent Start Date/Time: 2006-06-30
Source Contribution:

Earthdata International was contracted to provide LIDAR mapping services in the area of Caroline, Kent, and Queen

Anne's Counties, Maryland. Earthdata subcontracted the ground survey tasks to TerraSurv, Inc. The Global

Positioning System (GPS) was used to establish the control network.

The horizontal datum was the North American Datum of 1983, CORS adjustment (NAD 1983 CORS). The vertical

datum was the North American Vertical Datum of 1988(NAVD 1988).

There were a total of 27 stations occupied for this project. There were 19 new LIDAR control stations, 2 temporary

GPS base stations, 3 existing NSRS control stations, 2 CORS stations, and 1 airborne GPS base station used by

the flight crew. The network was observed in a radial configuration. A base receiver was established on a random

point and run throughout the observations in each area. Due to the large area covered, multiple base locations

were used. The temporary base stations were tied to the CORS and NSRS control stations.

| Source Geospatial Form: Diagram | Type of Source Media: Electronic mail system

Process Steps

Process Step 1

CC ID: 1132247
Description:

EarthData has developed a unique method for processing lidar data to identify and remove elevation points falling

on vegetation, buildings, and other aboveground structures. The algorithms for filtering data were utilized

within EarthData's proprietary software and commercial software written by TerraSolid. This software suite of tools

provides efficient processing for small to large-scale, projects and has been incorporated into ISO 9001

compliant production work flows. The following is a step-by-step breakdown of the process:

1. Using the lidar data set provided by EarthData, the technician performs calibrations on the data set.

2. Using the lidar data set provided by EarthData, the technician performed a visual inspection of the data to

verify that the flight lines overlap correctly. The technician also verified that there were no voids, and

that the data covered the project limits. The technician then selected a series of areas from the data set

and inspected them where adjacent flight lines overlapped. These overlapping areas were merged and a process

which utilizes 3-D Analyst and EarthData's proprietary software was run to detect and color code the differences

in elevation values and profiles. The technician reviewed these plots and located the areas that contained

systematic errors or distortions that were introduced by the lidar sensor.

3. Systematic distortions highlighted in step 2 were removed and the data was re-inspected. Corrections

and adjustments can involve the application of angular deflection or compensation for curvature of the ground

surface that can be introduced by crossing from one type of land cover to another.

4. The lidar data for each flight line was trimmed in batch for the removal of the overlap areas between flight lines.

The data was checked against a control network to ensure that vertical requirements were maintained.

Conversion to the client-specified datum and projections were then completed. The lidar flight line data sets were

then segmented into adjoining tiles for batch processing and data management.

5. The initial batch-processing run removed 95% of points falling on vegetation. The algorithm also removed the

points that fell on the edge of hard features such as structures, elevated roadways and bridges.

6. The operator interactively processed the data using lidar editing tools. During this final phase the

operator generated a TIN based on a desired thematic layer to evaluate the automated classification performed

in step 5. This allowed the operator to quickly re-classify points from one layer to another and recreate the TIN

surface to see the effects of edits. Geo-referenced images were toggled on or off to aid the operator in identifying

problem areas. The data was also examined with an automated profiling tool to aid the operator in the reclassification.

7. The final DEM was written to an LAS 1.0 format and also converted to ASCII

8. The point cloud data were also delivered in LAS 1.0

format and also converted to ASCII.

Process Date/Time: 2006-10-05 00:00:00

Process Step 2

CC ID: 1132248
Description:

EarthData utilizes a combination of proprietary and COTS processes to generate intensity images from

the lidar data. Intensity images are generated from the full points cloud (minus noise points) and the pixel

width is typically matched to the post spacing of the lidar data to achieve the best resolution.

The following steps are used to produce the intensity:

1) Lidar point cloud is tiled to the deliverable tile layout.

2) All noise points, spikes, and wells are deleted out of the tiles.

3) An EarthData proprietary piece of software, EEBN2TIF is then used to process out the intensity values of the lidar.

At this point, the pixel size is selected based on best fit or to match the client specification if noted in the SOW.

4) The software then generates TIF and .TFW files for each tile.

5) ArcView is used to review and QC the tiles before delivery.

Process Date/Time: 2006-11-20 00:00:00

Process Step 3

CC ID: 1132249
Description:

The NOAA Office for Coastal Management (OCM) received the files in las and ASCII format. The data were in

Maryland State Plane Projection, NAVD88 vertical datum and the vertical units of measure were meters. OCM performed

the following processing to the las data to make it available within Digital Coast:

1. The data were converted from Maryland State Plane coordinates to geographic coordinates.

2. The data were converted from NAVD88 (orthometric) heights to GRS80 (ellipsoid) heights using Geoid 03.

3. The LAS data were sorted by latitude and the headers were updated.

Process Date/Time: 2008-11-03 00:00:00

Catalog Details

Catalog Item ID: 49784
GUID: gov.noaa.nmfs.inport:49784
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