Science Applications International Corporation (SAIC) 20071212 remote-sensing image Chantilly, VA Science Applications International Corp. (SAIC) Bare Earth DEM Unknown\\ph40nsx5\v5$\PH\67481_USGS_Mexico\SAIC\Area_1\Area_1_Bare_earth\mb1_be_01.imgmb1_be_01.img LIDAR data is remotely sensed high-resolution elevation data collected by an airborne collection platform. Using a combination of laser rangefinding, GPS positioning and inertial measurement technologies; LIDAR instruments are able to make highly detailed Digital Elevation Models (DEMs) of the earth's terrain, man-made structures and vegetation. This data was collected at a resolution of 1 meter and includes reflective surface, last return, bare earth model and intensity data in separate data files. LIDAR data is used for 3D visualization, elevation based analysis and for feature extraction. Reflective surface data represents the DEM created by laser energy reflected from the first surface encountered by the laser pulse. Some energy may continue beyond this initial surface to be reflected by a subsequent surface as represented by the Last Return data. Intensity information is captured from the Reflective Surface pulse and indicates the relative energy returned to the sensor as compared to the energy transmitted. The Intensity image is not calibrated or normalized but indicates differences in energy absorption due to the the interaction of the surface materials with laser energy at the wavelength transmitted by the sensor. Bare earth model is created by identifying those returns that fall on the ground surface and interpolating a surface between these points. In this manner buildings and vegetation are removed from Bare Earth Model. This data set does not include bridges and overpasses in the Bare Earth model as the delineation point for these structures is not reliably discernable in the LiDAR data. en 20071005unknown20071015unknownREQUIRED: The year (and optionally month, or month and day) for which the data set corresponds to the ground. ground condition Complete Irregular -114.011532 -113.752630 32.261084 32.116038 216279.000000240300.0000003557258.0000003572712.000000 Light Distancing And Ranging LIDAR Digital Elevation Model DEM Average ground sample distance 1m 1meter resolution elevation model Bare Earth Model of earth surface with buildings and vegetation removed U.S. Department of Commerce, 1995, Countries, Dependencies, Areas of Special Sovereignty, and Their Principal Administrative Divisions (Federal Information Processing Standard (FIPS) 10-4): Washington, D.C., National Institute of Standards and Technology US Mexico U.S. Department of Commerce, 1987, Codes for the Indentification of the States, the District of Columbia and the outlying areas of the United States, and associated areas (Federal Information Processing Standards (FIPS) 5-2): Washington, D.C., National Institute of Standards and Technology. AZ City name Area 1 Location Description Border None None. However, 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 it's limitations. USGS n/a Unclassified US DODInformation Unclassified - distribution limited by Point of Contact Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.2.1350 Raster Dataset All IMG formatted image data are validated using commercial GIS software to ensure proper formatting and loading before delivery. This validation procedure ensures that data on delivery media is in correct physical format and is readable. LIDAR raster data is visually inspected for completeness to ensure that any gaps between flight lines or loss of signal represents less than 5% of required collection area. Areas of open water where loss of LIDAR signal is common are corrected to the best estimate of water level at time of collection. Areas of NODATA resulting from differences between required collection area and minimum bounding rectangle and/or areas of missing data are coded -999 to ensure compatibility between ESRI production software and ERDAS delivery format. LIDAR is self-illuminating and has minimal cloud penetration capability. Water vapor in steam plumes or particulates in smoke may cause reflection of LIDAR signals and loss of elevation information beneath these plumes. Glass structures and roofs may appear transparent to the LIDAR signal and therefore may not register on the reflective surface. Some asphalt formulations have been shown to absorb topographic LIDAR wavelength energy resulting in "pitting" of roof surfaces using this material. Horizontal accuracy of the source LIDAR data can be characterized by the rule of thumb of 1/2000th of flying height or roughly 0.5 meters for this collect. Spot checks in the field routinely are measured at 1/4000th of flying height but are not formally characterized. 0.5 Estimated based on rule of thumb and collection altitude - units in meters The vertical accuracy was tested following the National Standards for Spatial Data Accuracy. Based on a total of 85 control points, the average error between the bare earth LiDAR coverage and the control was -0.005 m with a root mean square error (RMSE) of 0.110 m. -0.005 m Average error between Bare Earth LiDAR coverage and control 0.110 m root mean square error (RMSE) Woolpert Unpublished Material Type of Scanner = LH Systems ALS50 Data Acquisition Height = 5,000-feet AGL Scanner Field of View = 25 degrees Scan Frequency = 36 Hertz Pulse Repetition Rate - 44.2 Kilohertz Aircraft Speed = 122 KIAS Swath Width = 2217-feet Nominal Ground Sample Distance = 3.0-feet Number of Returns Per Pulse = 2 (first and last) Distance Between Flight Lines = 1,331-feet 3000 DVD 20071005 20071015 ground condition LIDAR Raw spatial elevation information Process Step: Production Narrative: Using a LH Systems ALS50 Light Detection And Ranging (LiDAR) system, 108 flight lines of high density (submeter ground sample distance) data were collected along US and Mexico border in Arizona (approximately 1493 square kilometers). Two returns were recorded for each laser pulse along with an intensity value for each return. A total of eleven missions were flown over an eleven day period: October 5, 2007, October 6, 2007, October 7, 2007, October 8, 2007, October 9, 2007, October 10, 2007, October 11, 2007, October 12, 2007, October 13, 2007, October 14, 2007, and October 15, 2007. Nine airborne global positioning system (GPS) base stations were used to support the LiDAR data acquisition: New Tucson Base, Sasabe 0&1 Base 1, Sasabe 0&1 Base 2, Sasabe 2 Base 1, Sasabe 2 Base 2, Sasabe 3 V307, Sasabe 3 Z307, Sasabe 4 SIGMA, and Sasabe 4 YUMA BASE, pointed established by Woolpert using static method. In addition, one hundred four control points were surveyed through static methods. Airborne GPS data was differentially processed and integrated with the post processed IMU data to derive a smoothed best estimate of trajectory (SBET). The SBET was used to reduce the LiDAR slant range measurements to a raw reflective surface for each flight line. The coverage was classified to extract a bare earth digital elevation model (DEM) and separate last returns. Four layers of coverage were delivered in the ArcINFO ArcGrid binary format: reflective surface, bare-earth, last return and intensity. System Parameters: - Type of Scanner = LH Systems ALS50 - Data Acquisition Height = 5,000-feet AGL - Scanner Field of View = 25 degrees - Scan Frequency = 36 Hertz - Pulse Repetition Rate - 44.2 Kilohertz - Aircraft Speed = 122 KIAS - Swath Width = 2217-feet - Nominal Ground Sample Distance = 3.0-feet - Number of Returns Per Pulse = 2 (first and last) - Distance Between Flight Lines = 1,331-feet 200712 System Calibration Procedure: The ALS50 calibration and system performance is verified on a periodic basis using Woolpert's calibration range. The calibration range consists of a large building and runway. The edges of the building and control points along the runway have been located using conventional survey methods. Inertial measurement unit (IMU) misalignment angles and horizontal accuracy are calculated by comparing the position of the building edges between opposing flight lines. The scanner scale factor and vertical accuracy is calculated through comparison of LiDAR data against control points along the runway. Field calibration is performed on all flight lines to refine the IMU misalignment angles. IMU misalignment angles are calculated from the relative displacement of features within the overlap region of adjacent (and opposing) flight lines. The raw LiDAR data is reduced using the refined misalignment angles. 200712 Post Processing Procedure: Airborne GPS is differentially processed using the GrafNAV V4.20 software by Waypoint Consulting of Calgary, Alberta, Canada. The PDOP and distance separation by day is as follows: October 5, 2007 (New Tucson Base): Average PDOP = 1.5 Average Distance Separation: 85 km October 6, 2007 (New Tucson Base): Average PDOP = 2.0 Average Distance Separation: 90 km October 7, 2007 (Sasabe 0&1 Base 1): Average PDOP = 2.0 Average Distance Separation: 30 km October 8, 2007 (Sasabe 0&1 Base 1): Average PDOP = 2.0 Average Distance Separation: 60 km October 9, 2007 (Sasabe 0&1 Base 1): Average PDOP = 1.8 Average Distance Separation: 40 km October 10, 2007 (Sasabe 2 Base 1): Average PDOP = 2.0 Average Distance Separation: 40 km October 11, 2007 (Sasabe 2 Base 1): Average PDOP = 2.0 Average Distance Separation: 40 km October 12, 2007 (Sasabe 3 Z307): Average PDOP = 2.0 Average Distance Separation: 30 km October 13, 2007 (Sasabe 3 Z307): Average PDOP = 1.8 Average Distance Separation: 30 km October 14, 2007 (Sasabe 3 Z307): Average PDOP = 1.8 Average Distance Separation: 80 km October 15, 2007 (Sasabe 4 YUMA BASE): Average PDOP = 1.8 Average Distance Separation: 80 km IMU data is processed using the PosPac V4.2 software by Applanix Corporation of Richmond Hill, Ontario, Canada. The reflective surface is derived using the ALS Post Processor software by Leica Geosystems GIS & Mapping Division of Atlanta, Georgia. The classification and quality control (QC) of LiDAR data is carried out using a combination of Woolpert proprietary software and TerraScan software by Terrasolid Limited of Helinski, Finland. 200712 Data Consolidation and Review: Raw LiDAR data is delivered to contractor by collector. Four layers of coverage were delivered in the ArcINFO ArcGrid binary format: reflective surface, bare-earth, last return and intensity. These tiles are converted & merged into larger ESRI GRID files and reviewed for quality and consistency. Preliminary Bare Earth surface is reviewed and edited as required to remove or add features to bare earth surface as required by cartographic requirements 200712 Data Conversion: Merged tiles of ESRI GRID formatted data are converted to ERDAS Imagine image format. Areas coded as NODATA in ESRI GRID format are converted to -999 in ERDAS IMG format. IMG files are encoded with projection information for proper zone and datum as part of conversion process. Metadata is added. 200712 Dataset copied.C:\LIDAR\Metadata\bare_earth2007121310431100Dataset copied.C:\LIDAR\Metadata\Mexican_Border\bare_earth2007121311465000Metadata imported.Q:\MexicanBorderAreas\Area_1\metadata\fgdc-checked\bare_earth.xml2007121311472800 0 Raster Pixel 15454 24021 1 1.0000001.00000032Upper LeftFALSERun-Length Encoding (ESRI)1pixel RGBTRUE row and column 1.000000 1.000000 meters Universal Transverse Mercator120.999600-111.0000000.000000500000.0000000.000000 D_WGS_1984 WGS_1984 6378137.000000 298.257224 GCS_WGS_1984WGS_1984_UTM_Zone_12N North American Vertical Datum of 1988 meters Explicit elevation coordinate included with horizontal coordinates .01 Band_1 Single Band Image - IMAGINE FormatERDAS ObjectID Internal feature number. ESRI Sequential unique whole numbers that are automatically generated. Value Elevation value, in meters ERDASUnknownUnknownmeters.01 Count Number of cells with this valueERDASElevation statistics captured internally in IMAGINE data structure DVD ERDAS Imagine format on DVDNoneUpon request from distributor. Data release caveats may apply.Variable0.0000.000 No warranty expressed or implied is made by provider regarding the utility or the data on any other system, nor shall the act of distribution constitute any such warranty.TBD 20071217 USGS TBD Unknown Unknown Unknown Unknown USA TBD FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 local time http://www.esri.com/metadata/esriprof80.html ESRI Metadata Profile http://www.esri.com/metadata/esriprof80.html ESRI Metadata Profile enhttp://www.esri.com/metadata/esriprof80.htmlESRI Metadata Profile 20071217123142002007121311472800FALSE{A37D010E-8A7E-453C-822B-E90AB7BF7B02}200712171231420020071217file://\\ph40nsx5\v5$\PH\67481_USGS_Mexico\SAIC\Area_1\Area_1_Bare_earth\mb1_be_01.imgLocal Area Network0020.000Raster DatasetMicrosoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.2.1350mb1_be_01.img216279240300357271235572581-114.011532-113.7526332.26108432.1160381ISO 19115 Geographic Information - MetadataDIS_ESRI1.0datasetWGS_1984_UTM_Zone_12N21240211Meter1 Meter = 1 Meter(s)154541Meter1 Meter = 1 Meter(s)