Identification_Information: Citation: Citation_Information: Originator: Spatial Systems Associates, Inc. Publication_Date: 20050120 Title: LIDAR 2005 First and Last Return Points Geospatial_Data_Presentation_Form: model Series_Information: Series_Name: Maryland LIDAR Issue_Identification: 2005 Publication_Information: Publication_Place: Annapolis, Maryland Publisher: Maryland Department of Natural Resources Other_Citation_Details: 1. Airborne1, Inc. (flight firm) 2. Computational Consulting Services, LLC (processing firm) 3. Spatial Systems Associates, Inc. (post-processing firm) 4. Dewberry & Davis (QA/QC firm) Online_Linkage: Description: 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 First return points and the Last return points are considered to be "raw data". It is merely what was detected by the sensor as the closest likely ground based feature or farthest likely ground based feature for any individual laser shot. It is common that these points may represnt birds in flight, power lines, power poles, tree tops, cars, buildings, etc. It is also possible that a laser shot may bounce off of several features such as the side of a building, then a car, then another building and then return to the sensor, in which case the elevation reported may be below actual ground level. The first and last return points are typically processed to extract just the points that are believed to be ground, known as Bare Earth mass points. 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. 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). This data is available on DVD Only. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20050415 Beginning_Time: Unknown Ending_Date: 20050423 Ending_Time: Unknown Currentness_Reference: ground condition Status: Progress: In Work Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -76.252742 East_Bounding_Coordinate: -75.745017 North_Bounding_Coordinate: 39.728946 South_Bounding_Coordinate: 39.357231 Keywords: Theme: Theme_Keyword_Thesaurus: MMRG Theme_Keyword: elevation Theme: Theme_Keyword_Thesaurus: DNR General Theme_Keyword: bald earth Theme_Keyword: bare earth Theme_Keyword: DEM Theme_Keyword: Digital Elevation Model Theme_Keyword: DNR Theme_Keyword: elevation and derived products Theme_Keyword: elevation model Theme_Keyword: first return Theme_Keyword: gridded DEM Theme_Keyword: last return Theme_Keyword: LIDAR Theme_Keyword: surface model Theme_Keyword: terrain model Place: Place_Keyword_Thesaurus: Maryland Place_Keyword: Maryland Place_Keyword: USA Place_Keyword: Cecil Access_Constraints: Unless downloaded from the Internet, these data are distributed on DVD-ROM discs (specifically, DVD-R format for recorded DVD-ROMs) or via external hard disk. As such, access to a DVD-ROM drive capable of reding DVD-R discs or a computer with Firewire or USB connections and compatible operating system is required. Use_Constraints: 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. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Maryland Department of Natural Resources Contact_Person: Kevin Boone Contact_Position: Chief, Geographic Information Services Contact_Address: Address_Type: mailing and physical address Address: Tawes State Office Building 580 Taylor Avenue, E-2 City: Annapolis State_or_Province: Maryland Postal_Code: 21401-2397 Country: United States Contact_Voice_Telephone: 410-260-8753 Contact_TDD/TTY_Telephone: 410-260-8835 Contact_Facsimile_Telephone: 410-260-8759 Contact_Electronic_Mail_Address: kboone@dnr.state.md.us Hours_of_Service: 0800 - 1700 Eastern Time Data_Set_Credit: Spatial Systems Associates, Inc. was the prime contractor for this project. It partnered with Airborne1, Inc., Computational Consulting Services, Inc., NXL Construction Services, Inc and Dewberry LLC. Native_Data_Set_Environment: 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. Cross_Reference: Citation_Information: Originator: Spatial Systems Associates, Inc. Publication_Date: 20050120 Publication_Time: Unknown Title: LIDAR 2004 First and Last Returns Geospatial_Data_Presentation_Form: vector digital data Series_Information: Series_Name: Maryland LIDAR Issue_Identification: 2005 Publication_Information: Publication_Place: Annapolis, Maryland Publisher: Maryland Department of Natural Resources 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 & Davis (QA/QC firm) Online_Linkage: http://www.msgic.state.md.us/techtool Cross_Reference: Citation_Information: Originator: Spatial Systems Associates, Inc. Publication_Date: 20050930 Title: LIDAR 2005 Intensity Imagery Geospatial_Data_Presentation_Form: remote-sensing image Series_Information: Series_Name: Maryland LIDAR Issue_Identification: 2005 Publication_Information: Publication_Place: Annapolis, Maryland Publisher: Maryland Department of Natural Resources Other_Citation_Details: 1. Airborne 1, Inc. (flight firm) 2. Computational Consulting Services, LLC (processing firm) 3. Spatial Systems Associates, Inc. (post-processing firm) 4. Dewberry & Davis (QA/QC firm) Online_Linkage: Cross_Reference: Citation_Information: Originator: Spatial Systems Associates, Inc. Publication_Date: 20050120 Publication_Time: Unknown Title: LIDAR 2005 Bare Earth Mass Points Geospatial_Data_Presentation_Form: model Series_Information: Series_Name: Maryland LIDAR Issue_Identification: 2005 Publication_Information: Publication_Place: Annapolis, Maryland Publisher: Maryland Department of Natural Resources Other_Citation_Details: 1. Airborne1, Inc. (flight firm) 2. Computational Consulting Services, LLC (processing firm) 3. Spatial Systems Associates, Inc. (post-processing firm) 4. Dewberry & Davis (QA/QC firm) Online_Linkage: Cross_Reference: Citation_Information: Originator: Spatial Systems Associates, Inc. Publication_Date: 20050930 Title: LIDAR 2005 Gridded DEM Geospatial_Data_Presentation_Form: model Series_Information: Series_Name: Maryland LIDAR Issue_Identification: 2005 Publication_Information: Publication_Place: Annapolis, Maryland Publisher: Maryland Department of Natural Resources Other_Citation_Details: 1. Airborne 1, Inc. (flight firm) 2. Computational Consulting Services, LLC (processing firm) 3. Spatial Systems Associates, Inc. (post-processing firm) 4. Dewberry & Davis (QA/QC firm) Online_Linkage: Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: There are four (4) attributes in the First Returns and Last Returns files, representing the horizontal coordinates (easting & northing), vertical position observed and intensity. Random inspections were made to assure that each line in the file contained 4 values. Logical_Consistency_Report: 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 . Based upon the established accuracy of the bare earth mass points which are a derivative of the first and last return points, it is asserted that the first and last return points are themselves accurate. 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. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: The horizontal coordinate values were designed to meet NSSDA accuracy for data at 1:2400 scale. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: The RMSE value of 9.3 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 100 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 . Based upon the established accuracy of the bare earth mass points which are a derivative of the first and last return points, it is asserted that the first and last return points are themselves accurate. Quantitative_Vertical_Positional_Accuracy_Assessment: Vertical_Positional_Accuracy_Value: 9.3 Vertical_Positional_Accuracy_Explanation: The RMSE value is 9.3 cm. See the Vertical Positional Accuracy Report section for more information. Lineage: Process_Step: Process_Description: LIDAR Data Acquisition. Airborne 1, Inc. flew the project area with the LIDAR sensor. In an effort to permit correlation of the point values with tidal gauge stations, Airborne 1, 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 - 1.544 square meters per sample; *Average area sampling density -1.52 square meters per sample; *Swath width - 891.32 meters; *Flight altitude -1371 meters (4500 ft); *Flight line spacing - 445.66 meters w/50% overlap; *Scan frequency - 22 Hz; *Firing rate - 25 kHz; *Scan angle - 18 degrees; *Ground speed - 130 knots. When complete, the raw data was delivered to Spatial Systems. Process_Date: 20050424 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Maryland Department of Natural Resources Contact_Person: Kevin Boone Contact_Position: Chief, Geographic Information Services Contact_Address: Address_Type: mailing and physical address Address: Tawes State Office Building 580 Taylor Avenue, E-2 City: Annapolis State_or_Province: Maryland Postal_Code: 21401-2397 Country: United States Contact_Voice_Telephone: 410-260-8753 Contact_TDD/TTY_Telephone: 410-260-8835 Contact_Facsimile_Telephone: 410-260-8759 Contact_Electronic_Mail_Address: kboone@dnr.state.md.us Hours_of_Service: 0800 - 1700 Eastern Time Process_Step: Process_Description: LIDAR Data Processing. Computational Consulting Systems. The First and Last Return data was delivered to CCS in large blocks of data. CCS 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_Date: 20050830 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Maryland Department of Natural Resources Contact_Person: Kevin Boone Contact_Position: Chief, Geographic Information Services Contact_Address: Address_Type: mailing and physical address Address: Tawes State Office Building 580 Taylor Avenue, E-2 City: Annapolis State_or_Province: Maryland Postal_Code: 21401-2397 Country: United States Contact_Voice_Telephone: 410-260-8753 Contact_TDD/TTY_Telephone: 410-260-8835 Contact_Facsimile_Telephone: 410-260-8759 Contact_Electronic_Mail_Address: kboone@dnr.state.md.us Hours_of_Service: 0800 - 1700 Eastern Time Process_Step: Process_Description: LIDAR Data Post Processing. Spatial Systems Associates. SSA inventoried the first and last return points provided by CCS and prepared the final ascii text files for delivery via DVD-ROM. Process_Date: 20050930 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Ken Miller Contact_Organization: Maryland Department of Natural Resources Contact_Position: Chief. Watershed Information Services Division Contact_Address: Address_Type: mailing and physical address Address: Tawes State Office Building E-2 580 Taylor Avenue City: Annapolis State_or_Province: Maryland Postal_Code: 21401-2397 Country: USA Contact_Voice_Telephone: 410-260-8751 Contact_TDD/TTY_Telephone: 410-260-8835 Contact_Facsimile_Telephone: 410-260-8759 Contact_Electronic_Mail_Address: kenmiller@dnr.state.md.us Hours_of_Service: 0800 - 1700 Monday to Friday (Eastern Time) Process_Step: Process_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_Date: 20050630 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Maryland Department of Natural Resources Contact_Person: Kevin Boone Contact_Position: Chief, Geographic Information Services Contact_Address: Address_Type: mailing and physical address Address: Tawes State Office Building 580 Taylor Avenue, E-2 City: Annapolis State_or_Province: Maryland Postal_Code: 21401-2397 Country: United States Contact_Voice_Telephone: 410-260-8753 Contact_TDD/TTY_Telephone: 410-260-8835 Contact_Facsimile_Telephone: 410-260-8759 Contact_Electronic_Mail_Address: kboone@dnr.state.md.us Hours_of_Service: 0800 - 1700 Eastern Time Process_Step: Process_Description: 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 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 . Based upon the established accuracy of the bare earth mass points which are a derivative of the first and last return points, it is asserted that the first and last return points are themselves accurate. Process_Date: 20050930 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Maryland Department of Natural Resources Contact_Person: Kevin Boone Contact_Position: Chief, Geographic Information Services Contact_Address: Address_Type: mailing and physical address Address: Tawes State Office Building 580 Taylor Avenue, E-2 City: Annapolis State_or_Province: Maryland Postal_Code: 21401-2397 Country: United States Contact_Voice_Telephone: 410-260-8753 Contact_TDD/TTY_Telephone: 410-260-8835 Contact_Facsimile_Telephone: 410-260-8759 Contact_Electronic_Mail_Address: kboone@dnr.state.md.us Hours_of_Service: 0800 - 1700 Eastern Time Cloud_Cover: 0 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Point Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: Point Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: State Plane Coordinate System 1983 State_Plane_Coordinate_System: SPCS_Zone_Identifier: 1900 Lambert_Conformal_Conic: Standard_Parallel: 38.3 Standard_Parallel: 39.45 Longitude_of_Central_Meridian: -77 Latitude_of_Projection_Origin: 37.666667 False_Easting: 400000 False_Northing: 0 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: Coordinate Pair Coordinate_Representation: Abscissa_Resolution: 0.000256 Ordinate_Resolution: 0.000256 Planar_Distance_Units: meters Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 Ellipsoid_Name: Geodetic Reference System 80 Semi-major_Axis: 6378137 Denominator_of_Flattening_Ratio: 298.257 Vertical_Coordinate_System_Definition: Altitude_System_Definition: Altitude_Datum_Name: North American Vertical Datum of 1988 Altitude_Resolution: 0.001 Altitude_Distance_Units: meters Altitude_Encoding_Method: Explicit elevation coordinate included with horizontal coordinates Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: Point Entity_Type_Definition: Point feature derived from LiDAR shot. Entity_Type_Definition_Source: Spatial Systems Associates, Inc. Attribute: Attribute_Label: Intensity Attribute_Definition: Fourth field of a line of data. Measure of the amount of laser energy returned to the sensor for the LiDAR shot. The higher the value, the more reflectant was the surface that was struck. Attribute_Definition_Source: Spatial Systems Associates, Inc. Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0 Range_Domain_Maximum: 255 Attribute: Attribute_Label: xcoord Attribute_Definition: First field of a line of data. The point location x (east) coordinate. Attribute_Definition_Source: Spatial Systems Associates, Inc. Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0 Range_Domain_Maximum: 600000 Attribute_Units_of_Measure: meters Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: ycoord Attribute_Definition: Second field of a line of data. The point location y (north) coordinate. Attribute_Definition_Source: Spatial Systems Associates, Inc. Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0 Range_Domain_Maximum: 250000 Attribute_Units_of_Measure: meters Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: zvalue Attribute_Definition: Third field of a line of data. Elevation value in meters as detected by LiDAR system. Attribute_Definition_Source: Spatial Systems Associates, Inc. Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -99 Range_Domain_Maximum: 99999 Attribute_Units_of_Measure: meters Attribute_Measurement_Resolution: 0.01 Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: Maryland Department of Natural Resources Contact_Person: Kevin Boone Contact_Position: Chief, Geographic Information Services Contact_Address: Address_Type: mailing and physical address Address: Tawes State Office Building 580 Taylor Avenue, E-2 City: Annapolis State_or_Province: Maryland Postal_Code: 21401-2397 Country: United States Contact_Voice_Telephone: 410-260-8753 Contact_TDD/TTY_Telephone: 410-260-8835 Contact_Facsimile_Telephone: 410-260-8759 Contact_Electronic_Mail_Address: kboone@dnr.state.md.us Hours_of_Service: 0800 - 1700 Eastern Time Resource_Description: Offline Data Distribution_Liability: None Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: ASCII text files Format_Version_Date: 20021031 Digital_Transfer_Option: Offline_Option: Offline_Media: DVD-ROM Recording_Capacity: Recording_Density: 4.7 Gigabytes Recording_Density_Units: Gigabytes Recording_Format: DVD-R discs Compatibility_Information: DVD-ROM drives capable of reading DVD-R Digital_Form: Digital_Transfer_Information: Format_Name: ASCII text files Format_Version_Date: 20021031 Digital_Transfer_Option: Offline_Option: Offline_Media: external hard drive Recording_Capacity: Recording_Density: 250 Gigabytes Recording_Density_Units: Gigabytes Recording_Format: Hard disk that requires USB2.0 or FireWire (IEEE 1394) connections. Compatibility_Information: A computer with FireWire or USB connections and compatible operating system is required. Fees: Please refer to http://www.msgic.state.md.us/techtool Ordering_Instructions: Please refer to http://www.msgic.state.md.us/techtool Turnaround: 1-3 business days after receiving payment. Technical_Prerequisites: (1) Knowledge of Light Detection And Ranging (LiDAR) imagery is recommended. (2) Access to a DVD-ROM drive capable of reading DVD-R discs is required. (3) Access to a computer with FireWire or USB connections and compatible operating system in required for external hard drive. Metadata_Reference_Information: Metadata_Date: 20060831 Metadata_Review_Date: 20060831 Metadata_Future_Review_Date: 20070831 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Maryland Department of Natural Resources Contact_Person: Kevin Boone Contact_Position: Chief, Geographic Information Services Contact_Address: Address_Type: mailing and physical address Address: Tawes State Office Building 580 Taylor Avenue, E-2 City: Annapolis State_or_Province: Maryland Postal_Code: 21401-2397 Country: United States Contact_Voice_Telephone: 410-260-8753 Contact_TDD/TTY_Telephone: 410-260-8835 Contact_Facsimile_Telephone: 410-260-8759 Contact_Electronic_Mail_Address: kboone@dnr.state.md.us Hours_of_Service: 0800 - 1700 Eastern Time Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial metadata Metadata_Standard_Version: FGDC-STD-001-1998