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2012 NOAA American Samoa Lidar: Islands of Tutuila, Aunu'u, Ofu, Olosega, Ta'u and Rose Atoll

browse graphicThis kmz file shows the extent of coverage for the 2012 American Samoa lidar data set.
Light Detection and Ranging (LiDAR) data is remotely sensed high-resolution elevation data collected by an airborne collection platform. This LiDAR dataset is a survey of American Samoa including the islands of Tutuila, Aunu'u, Ofu, Olosega, Ta'u and Rose Atoll. The project area consists of approximately 75 square miles. The project design of the LiDAR data acquisition was developed to support a nominal post spacing of 1.0 meter or better (1.0 meter GSD). GMR Aerial Surveys Inc. d/b/a Photo Science, Inc. acquired 108 flight lines in 7 lifts between June 2012 and July 2012. This collection was for NOAA Coastal Services Center (CSC). The data collection was performed with a Beechcraft King Air 90 twin engine aircraft (tail number N87E) utilizing an Optech Gemini sensor; collecting multiple return x, y, and z as well as intensity data. The data were provided to CSC, classified as: Unclassified (1), Ground (2), Low Point (Noise) (7), Water (9), Breakline Edge (10), Overlap Unclassified (17) and Overlap Ground (18). The classifications available for download from the Digital Coast are: Unclassified (1), Ground (2), Low Point (Noise) 7, Water (9), Removed Ground (breakline edge) (10), and Overlap (12). The collection conditions were cloud and fog-free between the aircraft and the ground; streams must be within their banks; and low tide acquisition if at all possible. Data voids within a single swath were avoided whenever possible. Acceptable void areas are caused by a water body; areas of low near infrared (NIR) reflectivity such as asphalt or composition roofing and where appropriately filled in by another swath. Unfortunately, during the LiDAR acquisition there were a few mountain peaks where the clouds never lifted high enough to collect LiDAR. In order to post process the LiDAR data to meet task order specifications, Photo Science, Inc. established control points that were used to calibrate the LiDAR to known ground locations established on Tutuila. Please see the survey report for more details on ground control point collection at: ftp://ftp.csc.noaa.gov/pub/crs/beachmap/qa_docs/as/PhotoScience-AmSam_PostFlightAcquisitionReport_FINAL.pdf The dataset was developed based on a horizontal projection/datum of UTM NAD83 (PACP00), UTM Zone 2, meters. The vertical datum used during the collection, varied by island. NAVD88 (ASVD02), meters was used for the island of Tutuila (and Aunu'u). NAVD1988 (GEOID09), meters was used for the islands of Ofu, Olosega and Tau. Rose atoll was adjusted from Ellipsoid heights to a mean low water (MLW) datum. Upon receipt of the data, the NOAA Coastal Services Center converted the lidar data to geographic coordinates and ellipsoid heights using GEOID09. Rose Atoll data were converted to geographic coordinates and to ellipsoid heights using the MLW correction value of 22.8 m. Conversion is for data storage and Digital Coast provisioning purposes. LiDAR data was collected in RAW flightline swath format and processed to create Classified LAS 1.2 files.

Cite this dataset when used as a source.

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    Distribution Formats
    • LAZ
    Distributor DOC/NOAA/NOS/OCM > Office for Coastal Management, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    Point of Contact DOC/NOAA/NOS/OCM > Office for Coastal Management, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    843-740-1200
    coastal.info@noaa.gov
    Associated Resources
    • Post-Flight Acquisition Report
    Originator
    • DOC/NOAA/NOS/OCM > Office for Coastal Management, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    Publisher
    • DOC/NOAA/NOS/OCM > Office for Coastal Management, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    Date(s)
    • publication: 2013-06-01
    Data Presentation Form: Digital image
    Dataset Progress Status Complete
    Data Update Frequency: Unknown
    Supplemental Information: There were seven lifts flown out of Pago Pago International Airport for Tutuila and Aunuu and Fitiuta Airport for Ofu, Olosega, Tau and Rose Atoll collection. Base stations were set up at the airports and sensor Serial Number 246 was used for all flights: June 25, 2012 A June 25, 2012 B June 25, 2012 C June 27, 2012 July 5, 2012 A July 5, 2012 B July 5, 2012 C
    Purpose: The project was developed by the National Oceanic and Atmospheric Administration's (NOAA) Coastal Services Center in Charleston, SC to collect and deliver topographic elevation point data derived from multiple return light detection and ranging (LiDAR) measurements for American Samoa including islands of Tutila, Aunu'u, Ofu, Olosega, Ta'u and Rose Atoll. Data are intended for use in coastal management decision making. Classified LAS files are used to show the manually reviewed bare earth surface. This allows the user to create Intensity Images, Breaklines and Raster DEM.
    Use Limitations
    • These data depict the elevations at the time of the survey and are only accurate for that time. 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. Any conclusions drawn from analysis of this information are not the responsibility of NOAA or any of its partners. These data are NOT to be used for navigational purposes.
    Time Period: Unknown  to  Unknown
    Spatial Reference System: urn:ogc:def:crs:EPSG::4269 Ellipsoid in Meters
    Spatial Bounding Box Coordinates:
    N: -14.152104
    S: -14.564143
    E: -168.132827
    W: -170.851652
    Spatial Coverage Map:
    Themes
    • Bathymetry/Topography
    • model
    • LiDAR
    • DEM
    • Raster
    • breaklines
    • remote sensing
    • elevation
    Places
    • United States
    • American Samoa
    • Tutuila
    • Aunu'u
    • Ofu
    • Olosega
    • Ta'u
    • Rose Atoll
    Use Constraints No constraint information available
    Fees Fee information not available.
    Lineage Statement Lineage statement not available.
    Processor
    • Photo Science, Inc.
    • DOC/NOAA/NOS/OCM > Office for Coastal Management, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
    Processing Steps
    • Control Process: Photo Science, Inc. established control points on Tutuila that were used to calibrate the LiDAR to known ground locations to be used in the post processing of the LiDAR data. The points were located on relatively flat terrain on surfaces that generally consisted of grass, gravel, pavement or bare earth and were in well-defined discrete locations. See The Post Flight Aerial Acquisition and Calibration Report for additional collection parameters and methodologies: ftp://ftp.csc.noaa.gov/pub/crs/beachmap/qa_docs/as/PhotoScience-AmSam_PostFlightAcquisitionReport_FINAL.pdf Raw Flight Line Process: Applanix software was used in the post processing of the airborne GPS and inertial data that is critical to the positioning and orientation of the sensor during all flights. POSPac MMS provides the smoothed best estimate of trajectory (SBET) that is necessary for Optech's post processor to develop the point cloud from the LiDAR missions. The point cloud is the mathematical three dimensional collection of all returns from all laser pulses as determined from the aerial mission. At this point this data is ready for analysis, classification, and filtering to generate a bare earth surface model in which the above ground features are removed from the data set. The point cloud was manipulated within the Optech software; GeoCue, TerraScan, and TerraModeler software was used for the automated data classification, manual cleanup, and bare earth generation from this data. Project specific macros were used to classify the ground and to remove the side overlap between parallel flight lines. All data were manually reviewed and any remaining artifacts removed using functionality provided by TerraScan and TerraModeler. Classified LAS Process: All ground (ASPRS Class 2) LiDAR data inside of the Lake Pond and Double Line Drain hydro flattening breaklines were then classified to water (ASPRS Class 9) using TerraScan macro functionality. A buffer of 1 meter was also used around each hydro flattened feature to classify these ground (ASPRS Class 2) points to ignored ground (ASPRS Class 10). All Lake Pond Island and Double Line Drain Island features were checked to ensure that the ground (ASPRS Class 2) were reclassified to the correct classification after the automated classification was completed. A description of each deliverable class can be found below: Class 1 - Unclassified points; includes non-ground points such as buildings and vegetation. Class 2 - Ground points Class 7 - Noise points; includes all high and low noise points that do not represent legitimate features. Class 9 - Water points Class 10 - Ignored Ground points; includes all ground points that fall within a 1 meter buffer around any hydro breakline feature. Classifying these points aids in the hydro flattened DEM creation. Class 17 - Overlap Unclassified points; Overlap points that represent non-ground features. Class 18 - Overlap Ground points; Overlap points that represent the ground surface. These points were classified based on their x,y and z proximity to the Class 2 ground points. No manual cleanup was performed on these points. All overlap data was processed through automated functionality provided by TerraScan to classify the overlapping flight line data to class. Data was then run through additional macros to ensure deliverable classification levels matching the ASPRS LAS Version 1.2 Classification structure. GeoCue functionality was then used to ensure correct LAS Versioning. In-house software was used as a final QA/QC check to provide LAS Analysis of the delivered tiles. QA/QC checks were performed on a per tile level to verify final classification metrics and full LAS header information.
    • The NOAA Coastal Services Center (CSC) received the files in las format. The files contained LiDAR elevation and intensity measurements. The data were delivered in UTM Zone 2 projection, NAD83 datum, meters. Data available are classified as follows: Unclassified (1), Ground (2), Low Point (Noise) 7, Water (9), Removed Ground (breakline edge) (10), and Overlap (12). CSC performed the following processing for data storage and Digital Coast provisioning purposes: 1. The data were converted from UTM Zone 2, NAD83 coordinates to geographic coordinates. 2. The Tutuila (and Aunu'u), Ofu, Olosega, and Tau data were converted from NAVD88 (orthometric) heights to GRS80 (ellipsoid) heights using Geoid09. 3. The Rose Atoll data were converted from MLW to ellipsoid (using MLW correction value of 22.8 m) 4. The data were converted to LAZ format.
    • The NOAA National Geophysical Data Center (NGDC) received lidar data files via ftp transfer from the NOAA Coastal Services Center. The data are currently being served via NOAA CSC Digital Coast at http://www.csc.noaa.gov/digitalcoast/. The data can be used to re-populate the system. The data are archived in LAS or LAZ format. The LAS format is an industry standard for LiDAR data developed by the American Society of Photogrammetry and Remote Sensing (ASPRS); LAZ is a loseless compressed version of LAS developed by Martin Isenburg (http://www.laszip.org/). The data are exclusively in geographic coordinates (either NAD83 or ITRF94). The data are referenced vertically to the ellipsoid (either GRS80 or ITRF94), allowing for the ability to apply the most up to date geoid model when transforming to orthometric heights.

    Metadata Last Modified: 2013-06-28

    For questions about the information on this page, please email: mike.sutherland@noaa.gov