Science Applications International Corporation (SAIC) 200605 remote-sensing image Chantilly, VA Science Applications International Corp. (SAIC) Bare Earth DEM honolulu_downtown_bare_earth.img\\144-vdu\lidar_temp\Honolulu\Delivery\honolulu_downtown_bare_earth.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 20051222 20051229 REQUIRED: The year (and optionally month, or month and day) for which the data set corresponds to the ground. ground condition Complete Irregular -80.004604 -79.852824 32.927503 32.763689 591000.000000642000.0000002350000.0000002369000.000000 Light Distancing And Ranging LIDAR Digital Elevation Model DEM Average ground sample distance 1m 1meter resolution elevation model Bare Earth 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 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. HI City name Honolulu Location Description Downtown 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. National Geospatial-Intelligence Agency n/a Unclassified Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.1.0.722 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. Better than 1m The vertical accuracy was tested following the National Standards for Spatial Data Accuracy. Based on a total of 61 points (53 QC checkpoints, and 8 GPS points), the average error between the bare earth LiDAR coverage and the control was 0.002 m with a root mean square error (RMSE) of 0.089 m. 0.002 m Average error between Bare Earth LiDAR coverage and control 0.089 m root mean square error (RMSE) Woolpert LLP Unpublished Material - Type Of Scanner = LH Systems ALS50 - Data Acquisition Height = 3,000-feet AGL - Scanner Field Of View = 40 degrees - Scan Frequency = 36 Hertz - Pulse Repetition Rate - 52.3 KiloHertz - Aircraft Speed = 130 KIAS - Swath Width = 2184-feet - Nominal Ground Sample Distance = 3.0-feet - Number of Returns Per Pulse = 2 (first and last) - Distance Between Flight Lines = 1,529-feet 3000 DVD-ROM 20051228 20051229 ground condition LIDAR Woolpert LLP Unpublished Material 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. Production Narrative: Using a LH Systems ALS50 Light Detection and Ranging LiDAR) system, 122 flight lines of high density (submeter ground sample distance) data were collected over Honolulu, HI area (approximately 395 square kilometers). Two returns were recorded for each laser pulse along with an intensity value for each return. One mission was flown over a seven days period: on December 22, 23, 24, 25, 26 and 29th, 2005. Two airborne global positioning system (GPS) base stations were used to support the LiDAR data acquisition: AFS1 and ZHN1, sites that Woolpert located using static GPS positioning methods. In addition, eight control points were surveyed through real-time kinematic (RTK) methods, tied into NGS points 1 5, 161 2340 TIDAL 21, A 111, B 111, L 13, STATE SURVEY 4 22, WAIKIKI 3, ZHN B to support the final accuracy analysis. 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. 200512 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. Post Processing Procedure: Airborne GPS is differentially processed using the POSGPS V4.2 software by Applanix Corporation of Richmond Hill, Ontario, Canada. The PDOP and distance separation by day is as follows: Mission 1 - December 22, 2005 (AFS1): Average PDOP = 2.5 Average Distance Separation: 15 km Mission 2 - December 22, 2005 (AFS1): Average PDOP = 2.3 Average Distance Separation: 15 km Mission 3 - December 23, 2005 (AFS1): Average PDOP = 2.5 Average Distance Separation: 20 km Mission 4 - December 23 2005 (AFS1): Average PDOP = 2 Average Distance Separation: 25 km Mission 5 - December 24, 2005 (AFS1): Average PDOP = 2 Average Distance Separation: 15 km Mission 6 - December 24, 2005 (AFS1): Average PDOP = 2.5 Average Distance Separation: 18 km Mission 7 - December 24, 2005 (AFS1): Average PDOP = 2 Average Distance Separation: 15 km Mission 8 - December 25, 2005 (AFS1): Average PDOP = 1.6 Average Distance Separation: 25 km Mission 9 - December 26, 2005 (AFS1): Average PDOP = 3 Average Distance Separation: 20 km Mission 10 - December 26, 2005 (AFS1): Average PDOP = 2.2 Average Distance Separation: 18 km Mission 11 - December 26, 2005 (AFS1): Average PDOP = 2.8 Average Distance Separation: 10 km Mission 12 - December 29, 2005 (AFS1): Average PDOP = 1.2 Average Distance Separation: 10 km Mission 13 - December 29, 2005 (AFS1): Average PDOP = 1.6 Average Distance Separation: 12 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. 200512 Data Consolidation and Review: Raw LiDAR data is delivered in small tiles in ESRI GRID format. These tiles are merged into larger ESRI GRID files, limited by the 2.1GB limit of this format, 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. 200602 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. Due to ESRI GRID size limitation of 2.1GB, contiguous areas that would result in larger file sizes are tiled in the fewest number of tiles permitted by the 2.1GB limit. 200605 Post Conversion Q/C: Converted IMG files are verified for format and content in ERDAS IMAGINE environment. Metadata and spatial reference were also added. 200605 Transfer to delivery media: Data is transferred from hard-disk to DVD delivery media using a Primera Bravo DVD/CDROM disc publishing hardware. 200605 Metadata imported.S:\Honolulu\Metadata\bareearth.xml2006060713005600 n/a Raster Pixel 19000 51000 1 1.0000001.00000032Upper LeftFALSENone1pixel RGBTRUEERDAS IMAGINE row and column 1.000000 1.000000 meters Universal Transverse Mercator40.999600-159.0000000.000000500000.0000000.000000 D_WGS_1984 WGS_1984 6378137.000000 298.257224 GCS_WGS_1984WGS_1984_UTM_Zone_4N North American Vertical Datum of 1988 .1 meters Explicit elevation coordinate included with horizontal coordinates Band_1 ObjectID Internal feature number. ESRI Sequential unique whole numbers that are automatically generated. Value Elevation value, in meters Count Downloadable Data 0.000 0.000 20060607 National Geospatial-Intelligence Agency (NGA) REQUIRED: The person responsible for the metadata information. 21300 Sunrise Valley Drive Reston VA 20191 USA REQUIRED: The telephone number by which individuals can speak to the organization or individual. 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 2006060714040300{C08072FE-6634-4783-AEC0-9F254A3DFA7D}2006060713005600FALSE2006060714040300DefineProjection S:\Honolulu\Delivery\honlulu_downtown_bare_earth.img PROJCS['WGS_1984_UTM_Zone_4N',GEOGCS['GCS_WGS_1984',DATUM['D_WGS_1984',SPHEROID['WGS_1984',6378137.0,298.257223563]],PRIMEM['Greenwich',0.0],UNIT['Degree',0.0174532925199433]],PROJECTION['Transverse_Mercator'],PARAMETER['False_Easting',500000.0],PARAMETER['False_Northing',0.0],PARAMETER['Central_Meridian',-159.0],PARAMETER['Scale_Factor',0.9996],PARAMETER['Latitude_Of_Origin',0.0],UNIT['Meter',1.0]] S:\Honolulu\Delivery\honlulu_downtown_bare_earth.img20060607Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.1.0.722honolulu_downtown_bare_earth.img591000642000236900023500001-158.122961-157.62992821.4210321.2461071ISO 19115 Geographic Information - MetadataDIS_ESRI1.0dataset002file://\\144-vdu\lidar_temp\Honolulu\Delivery\honolulu_downtown_bare_earth.imgLocal Area Network0.000Raster Dataset21510001Meter1 Meter = 1 Meter(s)190001Meter1 Meter = 1 Meter(s)WGS_1984_UTM_Zone_4N