NMMR Metadata gov.noaa.csc.maps:md2002

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(NMMR Metadata gov.noaa.csc.maps:md2002)

2003 Maryland LIDAR mapping project

Frequently-asked questions:

What does this data set describe?
Who produced the data set?
Why was the data set created?
How was the data set created?
How reliable are the data; what problems remain in the data set?
How can someone get a copy of the data set?
Who wrote the metadata?
Mission Information?
Platform Information?
Instrument Information (General Overview)
Instrument Information (Sensor Specific)

What does this data set describe?

Title:

2003 Maryland LIDAR mapping project

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. The bare earth mass points data show the calculated elevation of the earth's surface (the ground, without objects such as trees or buildings). 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.

Supplemental information:

Please contact metadata@csc.noaa.gov for this information.

1. How should this data set be cited?

Origin:	`DOC/NOAA/NOS/CSC/CRS > Coastal Remote Sensing Program, Coastal Services Center, National Ocean Service, NOAA, U.S. Department of Commerce`
Pub Date:	`20061018`
Title:	`2003 Maryland LIDAR mapping project`

Online links:

http://www.csc.noaa.gov/lidar

Other citation details:

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

2. What geographic area does the data set cover?

Bounding coordinates:

West: -75.569660

East: -75.023956

North: 38.468258

South: 37.979873

3. What does it look like?

Please contact metadata@csc.noaa.gov for this information.

4. What is the temporal coverage of the data set?

Begdate:	`20020901`
Begtime:	`Unknown`
Enddate:	`20030101`
Endtime:	`Unknown`

5. What is the geospatial form of this data set?

Please contact metadata@csc.noaa.gov for this information.

6. How does the data set represent geographic features?

How are geographic features stored in the data set?

As a Point data set

What is the coordinate system used to represent geographic features?

Please contact metadata@csc.noaa.gov for this information.

7. What are the contents of this dataset?

Please contact metadata@csc.noaa.gov for this information.

Attribute Details

Please contact metadata@csc.noaa.gov for this information.

8. What were the instruments or sensors used to collect the data

Please contact metadata@csc.noaa.gov for this information.

9. What satellites, boats or other platforms housed the instruments?

Please contact metadata@csc.noaa.gov for this information.

10. What missions supported the platforms?

Please contact metadata@csc.noaa.gov for this information.

11. What online links are contained in this metadata record?

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

DOC/NOAA/NOS/CSC/CRS > Coastal Remote Sensing Program, Coastal Services Center, National Ocean Service, NOAA, U.S. Department of Commerce

2. Who also contributed to the data set?

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) Coastal Services Center (CSC).

3. To whom should users address questions about the data?

TCM Project Scientist Coastal 2234 South Hobson Avenue Charleston South Carolina 29405 United States (843) 740-1200 (voice) (fax) csc@csc.noaa.gov (fax)

Back to Top Why was the data set created? 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. Back to Top How was the data set created? 1. What are the data sources? Elevation data 2. What changes have been made? Date Event 20040120 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. 20040120 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, 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. 20040120 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. 20040120 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. 20040120 LIDAR Data Quailty 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>. 20040528 The NOAA Coastal Services Center (CSC) received ASCII files containing the bared-earth elevation and intensity data from Maryland Department of Natural Resources. CSC 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, lon, 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 20060103 The NOAA National Geophysical Data Center (NGDC) received Lidar data files on external harddrive. The disk contains LiDAR data from the NOAA Coastal Services Center. This data is currently being served via LDART at http://www.csc.noaa.gov/ldart . This data can be used to re-populate the system. The data are provided on this disk in two forms, ascii x,y,z data and also in LAS format. LAS format is an industry standard for serving LiDAR data. The data are exclusively in geographic coordinates, however, the datums used vary. Most is NAD 83, however some is in ITRF. Vertical systems include both ellipsoid (ITRF and NAD 83) and NAVD 88. For NAVD 88 values, Geiod 03 is primarily used; however, data received in NAVD 88 prior to 2003 was processed using Geoid 99. 3. Who is the person responsible for change? Tawes State Office Building E-2 580 Taylor Avenue Annapolis Maryland 21401-2397 USA 410-260-8751 (voice) 410-260-8759 (fax) kenmiller@dnr.state.md.us Coastal Remote Sensing Program 2234 South Hobson Avenue Charleston South Carolina 29405 United States (843) 740-1200 (voice) csc@csc.noaa.gov Kelly Stroker DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce NOAA/NESDIS/NGDC E/GC1 325 Broadway Boulder CO 80305-3328 USA (303) 497-4603 (voice) (303) 497-6513 (fax) kelly.stroker@noaa.gov Hours of Service: 0800 - 1700 Monday to Friday (EST) Tawes State Office Building E-2 580 Taylor Avenue Annapolis Maryland 21401-2397 USA 410-260-8751 (voice) 410-260-8759 (fax) kenmiller@dnr.state.md.us Coastal Remote Sensing Program 2234 South Hobson Avenue Charleston South Carolina 29405 United States (843) 740-1200 (voice) csc@csc.noaa.gov Kelly Stroker DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce NOAA/NESDIS/NGDC E/GC1 325 Broadway Boulder CO 80305-3328 USA (303) 497-4603 (voice) (303) 497-6513 (fax) kelly.stroker@noaa.gov Hours of Service: 0800 - 1700 Monday to Friday (EST) Tawes State Office Building E-2 580 Taylor Avenue Annapolis Maryland 21401-2397 USA 410-260-8751 (voice) 410-260-8759 (fax) kenmiller@dnr.state.md.us Coastal Remote Sensing Program 2234 South Hobson Avenue Charleston South Carolina 29405 United States (843) 740-1200 (voice) csc@csc.noaa.gov Kelly Stroker DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce NOAA/NESDIS/NGDC E/GC1 325 Broadway Boulder CO 80305-3328 USA (303) 497-4603 (voice) (303) 497-6513 (fax) kelly.stroker@noaa.gov Hours of Service: 0800 - 1700 Monday to Friday (EST) Tawes State Office Building E-2 580 Taylor Avenue Annapolis Maryland 21401-2397 USA 410-260-8751 (voice) 410-260-8759 (fax) kenmiller@dnr.state.md.us Coastal Remote Sensing Program 2234 South Hobson Avenue Charleston South Carolina 29405 United States (843) 740-1200 (voice) csc@csc.noaa.gov Kelly Stroker DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce NOAA/NESDIS/NGDC E/GC1 325 Broadway Boulder CO 80305-3328 USA (303) 497-4603 (voice) (303) 497-6513 (fax) kelly.stroker@noaa.gov Hours of Service: 0800 - 1700 Monday to Friday (EST) Tawes State Office Building E-2 580 Taylor Avenue Annapolis Maryland 21401-2397 USA 410-260-8751 (voice) 410-260-8759 (fax) kenmiller@dnr.state.md.us Coastal Remote Sensing Program 2234 South Hobson Avenue Charleston South Carolina 29405 United States (843) 740-1200 (voice) csc@csc.noaa.gov Kelly Stroker DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce NOAA/NESDIS/NGDC E/GC1 325 Broadway Boulder CO 80305-3328 USA (303) 497-4603 (voice) (303) 497-6513 (fax) kelly.stroker@noaa.gov Hours of Service: 0800 - 1700 Monday to Friday (EST) Tawes State Office Building E-2 580 Taylor Avenue Annapolis Maryland 21401-2397 USA 410-260-8751 (voice) 410-260-8759 (fax) kenmiller@dnr.state.md.us Coastal Remote Sensing Program 2234 South Hobson Avenue Charleston South Carolina 29405 United States (843) 740-1200 (voice) csc@csc.noaa.gov Kelly Stroker DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce NOAA/NESDIS/NGDC E/GC1 325 Broadway Boulder CO 80305-3328 USA (303) 497-4603 (voice) (303) 497-6513 (fax) kelly.stroker@noaa.gov Tawes State Office Building E-2 580 Taylor Avenue Annapolis Maryland 21401-2397 USA 410-260-8751 (voice) 410-260-8759 (fax) kenmiller@dnr.state.md.us Coastal Remote Sensing Program 2234 South Hobson Avenue Charleston South Carolina 29405 United States (843) 740-1200 (voice) csc@csc.noaa.gov Kelly Stroker DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce NOAA/NESDIS/NGDC E/GC1 325 Broadway Boulder CO 80305-3328 USA (303) 497-4603 (voice) (303) 497-6513 (fax) kelly.stroker@noaa.gov Hours of Service: 7:30-5:00 Mountain 4. What data sources were used in this process? Please contact metadata@csc.noaa.gov for this information. 5. What data sources were produced in this process? Please contact metadata@csc.noaa.gov for this information. Back to Top How reliable are the data; what problems remain in the data set? How well have the observations been checked? None available How accurate are the geographic locations? The horizontal coordinate values were designed to meet NSSDA accuracy for data at 1:2400 scale. How accurate are the heights or depths? 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>. Where are the gaps in the data? What is missing? 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. How consistent are the relationships among the observations, including topology? 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>. Back to Top How can someone get a copy of the data set? 1. Are there legal restrictions on access or use of the data? Access Constraints: none Use Constraints: 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. 2. Who distributes the data set? Coastal Remote Sensing Program Manager NOAA 2234 South Hobson Avenue Charleston SC 29405-2413 none (voice) (fax) csc@csc.noaa.gov (fax) Kelly Stroker DOC/NOAA/NESDIS/NGDC NOAA/NESDIS/NGDC E/GC1 325 Broadway Boulder CO 80305-3328 USA (303) 497-4603 (voice) (303) 497-6513 (fax) kelly.stroker@noaa.gov (fax) Coastal Remote Sensing Program Manager NOAA 2234 South Hobson Avenue Charleston SC 29405-2413 none (voice) (fax) csc@csc.noaa.gov (fax) Kelly Stroker DOC/NOAA/NESDIS/NGDC NOAA/NESDIS/NGDC E/GC1 325 Broadway Boulder CO 80305-3328 USA (303) 497-4603 (voice) (303) 497-6513 (fax) kelly.stroker@noaa.gov (fax) Hours of Service: 7:30-5:00 Mountain Contact Instructions: Contact Data Center 3. What's the resource identifier I need to order this data set? Please contact metadata@csc.noaa.gov for this information. 4. What legal disclaimers am I supposed to read? Any conclusions drawn from analysis of this information are not the responsibility of NOAA or the Coastal Services Center. Disclaimer While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty. 5. How can I download or order the data? Availability in non-digital form: Please contact metadata@csc.noaa.gov for this information. Availability in digital form: Format Name: Please contact metadata@csc.noaa.gov for this information. Network Links: Please contact metadata@csc.noaa.gov for this information. Off line media: Please contact metadata@csc.noaa.gov for this information. Cost: Please contact metadata@csc.noaa.gov for this information. Special Instructions: Please contact metadata@csc.noaa.gov for this information. Delivery: Please contact metadata@csc.noaa.gov for this information. 6. Is there some other way to get the data? This data can be obtained on-line at the following URL: http://www.csc.noaa.gov/ldart. The National Geophysical Data Center serves as the archive for this LIDAR data. NGDC should only be contacted for this data if it cannot be obtained from NOAA Coastal Services Center. 7. What hardware or software do I need in order to use the data set? Please contact metadata@csc.noaa.gov for this information. Back to Top Who wrote the metadata? Metadata author: Keil Schmid NOAA Coastal Services Center 2234 South Hobson Avenue Charleston SC 29405-2413 none (voice) metadata@csc.noaa.gov Date Last Modified 20040528 Metadata Standard FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 Metadata Extensions Used Please contact metadata@csc.noaa.gov for this information. Back to Top MISSION INFORMATION 1. What is the mission name? Mission name not available 2. What is the mission description? Mission description not available 3. When did the mission start? Start date not available 4. If complete, when did the mission end? End date not available 5. What significant events occurred during this mission? Events not available PLATFORM INFORMATION 1. What platform/s (satellites, boats, planes) were utilized to create this dataset? Please contact metadata@csc.noaa.gov for this information. 2. Who were the platform sponsors? Platform sponsor not available 3. What is the description of the platform/s? 4. What are the satellite orbit parameters? 5. What are the aircraft flight track properties? Flight properties not available INSTRUMENT INFORMATION (General Overview) 1. What instruments were used to collect the data? Instrument name not available 2. What are the instrument types? (e.g. imager, sounder, magnetometer, gps reciever, etc) Instrument type not available 3. What are operational modes of the instruments (crosstrack, initialization, solar calibration, etc.) Operational mode not available 4. How do the instruments collect data? (e.g. whiskbroom, laser, panoramic, etc)? Collection type not available 5. What are the position and orientation of the instrument components on the platform? Sensor orientation not available INSTRUMENT INFORMATION (Sensor Specific) 1. What is the sensor rotation description? Rotation description not available 2. What are the scan geometric properties? Scan geometric properties not available 3. What are the scan cross track properties? Scan cross track properties not available 4. What is the scan cross track description? Scan cross track description 5. What are the instaneous field of view properties? Instaneous field of view properties not available 6. What are the sample properties? Sample properties not available 7. What are the scan radiometric properties? Scan radiometric properties not available 8. What are the number of wavelength bands? Number of wavelength bands not available 9. What are the wavelength band descriptions? Wavelength band descriptions not available 10. What are the wavelength band properties? Wavelength band properties not available 11. What is the band quality? Band quality information available 12. What is the receiver polarization? Receiver polarization not available 13. What are the instrument references? References not available

Date	Event
20040120	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.
20040120	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, 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.
20040120	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.
20040120	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.
20040120	LIDAR Data Quailty 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>.
20040528	The NOAA Coastal Services Center (CSC) received ASCII files containing the bared-earth elevation and intensity data from Maryland Department of Natural Resources. CSC 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, lon, 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
20060103	The NOAA National Geophysical Data Center (NGDC) received Lidar data files on external harddrive. The disk contains LiDAR data from the NOAA Coastal Services Center. This data is currently being served via LDART at http://www.csc.noaa.gov/ldart . This data can be used to re-populate the system. The data are provided on this disk in two forms, ascii x,y,z data and also in LAS format. LAS format is an industry standard for serving LiDAR data. The data are exclusively in geographic coordinates, however, the datums used vary. Most is NAD 83, however some is in ITRF. Vertical systems include both ellipsoid (ITRF and NAD 83) and NAVD 88. For NAVD 88 values, Geiod 03 is primarily used; however, data received in NAVD 88 prior to 2003 was processed using Geoid 99.