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2011 U.S. Geological Survey Topographic LiDAR: LiDAR for the North East

browse graphicThis kmz file shows the extent of coverage for the 2011 USGS Lidar for the Northeast data set.
USGS Contract: G10PC00026, Task Order Number: G10PD02143 Task Order Numbers: G10PD01027 (ARRA) and G10PD02143 (non-ARRA) The LiDAR for the North East Project, funded in large part by the American Recovery and Reinvestment Act (ARRA) of 2009, as well as, other funding sources was designed to help stimulate the U.S. economy and provide for more accurate floodplain mapping in the North East, representing the start of a regional LiDAR collection program that served as a test case for a national elevation program. Lead by the United States Geological Survey's (USGS) National Geospatial Program Office and the State of Maine's Office of GIS with active collaboration and participation by other federal, state and local agencies resulted in LiDAR acquisition and processing of over 8,000 sq. miles of (LiDAR) data of a coastal zone spanning six North Eastern states, including Maine, New Hampshire, Massachusetts, Connecticut, Rhode Island, and New York. USGS's National Geospatial Technical Operations Center (USGS NGTOC) in Rolla, MO provided project management and quality control oversight for the project which consisted of two Task Orders issued to USGS contractor, GMR Aerial Surveys inc. d/b/a Photo Science (contractor), for task order execution through the use of USGS's Geospatial Products and Services Contract (USGS Contract: G10PC00026). Task Order specifications included state/area specific vertical accuracy, nominal post spacing and tide coordinated acquisition requirements. To see state/area specific information please see the individual project metadata links in the Supplemental_Information section below. NOAA CSC received the topographic LAS files from USGS and Maine Office of GIS. The data was minimally processed by CSC, however the classes were adjusted (individual points were not changed): NOAA CSC Modified Classification Scheme: Class 1: Unclassified Class 2: Ground Class 7: Noise Class 9: Water Class 10: Breakline Proximity Class 14: Bare (Open) Water Class 15: Overlap Water Class 16: Overlap Bare (Open) Water Class 17: Overlap Default Class 18: Overlap Ground

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    Distribution Formats
    • LAZ
    Distributor DOC/NOAA/NOS/CSC > Coastal Services Center, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    Point of Contact State of Maine, Office of Information Technology
    (207)215-5530
    Associated Resources
    • Map of Nominal Point Spacing
    • Map of Vertical Accuracy
    Originator
    • DOC/NOAA/NOS/CSC > Coastal Services Center, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    Originator
    • DOI/USGS > United States Geological Survey, U.S. Department of the Interior
    Originator
    • Maine's Office of GIS (MEGIS)
    Publisher
    • DOC/NOAA/NOS/CSC > Coastal Services Center, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    Date(s)
    • publication: 2013-08-01
    Data Presentation Form: Digital image
    Dataset Progress Status Complete
    Data Update Frequency: As needed
    Purpose: LiDAR data has a wide range of applications such as earthquake hazard studies, hydrologic modeling, forestry, coastal engineering, roadway and pipeline engineering, flood plain mapping, wetland studies, geologic studies and a variety of analytical and cartographic projects.
    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: 2010-12-20  to  2011-12-11
    Spatial Reference System: urn:ogc:def:crs:EPSG::4269 Ellipsoid in Meters
    Spatial Bounding Box Coordinates:
    N: 45.193096
    S: 40.574468
    E: -66.938738
    W: -74.236678
    Spatial Coverage Map:
    Themes
    • Topography/Bathymetry
    • Elevation
    • Model
    • LiDAR
    • Remote Sensing
    Places
    • US
    • Coastal Northeast US
    • Massachusetts
    • Rhode Island
    • New Hampshire
    • Maine
    • New York
    • Connecticut
    Use Constraints No constraint information available
    Fees Fee information not available.
    Lineage Statement Lineage statement not available.
    Processor
    • DOC/NOAA/NOS/CSC > Coastal Services Center, 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: James W. Sewall Company was contracted by Photo Science, Inc. to locate a total of 156 calibration control points (60 for MA, 31 for NY, 11 for CT18, 4 for CT19, 25 for NH and 25 for RI) used in the post processing of the LiDAR data as well as 20 quality assurance check points for each state. The points were located on relatively flat terrain on surfaces that generally consisted of grass, gravel or bare earth. See Final Survey Reports for additional collection parameters and methodologies. 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 or Leica 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 was 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 new class has been added to the dataset to represent the bare water of the ocean areas collected throughout the project area. ASPRS Class 14 is being used to represent the bare water ocean surface. While attempts were made to remove all extraneous features above the surface of the water, there may be above surface features classified to this class. Some islands below the required collection specifications have been classified to this class as well. This class was also used during the creation of the ERDAS Imagine Raster DEM files. The Ocean Shoreline and Ocean Island breaklines were used to complete the automated classification of these classes within the final LAS files. All overlap data was processed through automated functionality provided by TerraScan to classify the overlapping flight line data to approved classes by USGS. The overlap data was classified to Class 17 (USGS Overlap Default), Class 18 (USGS Overlap Ground), Class 25 (USGS Overlap Water), and Class 30 (USGS Overlap Bare Water). These classes were created through automated processes only and were not verified for classification accuracy. Due to software limitations within TerraScan, these classes were used to trip the Withheld bit within various software packages. These processes were reviewed and accepted by USGS through multiple conference calls and pilot study areas. 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. Hydro Flattening Breakline Process: Class 2 LiDAR was used to create a bare earth surface model. The surface model was then used to heads-up digitize 2D breaklines of inland streams and rivers with a 30 meter nominal width and Inland Ponds and Lakes of 8,000 sq. meters or greater surface area. Ocean Shoreline and Ocean Island features were collected at appropriate elevations on an overall review of the surface models to determine the land water breaklines. These features were used to determine the classification within the Classified LAS files. These features can be used to represent a flat water surface, but were not run through the same project quality control procedures as the inland water body features. Elevation differences between ocean shoreline and ocean islands will be found. This is due in large part to the coastal water elevation changes, found between missions, as well as flightline to flightline. Elevation values were assigned to all Inland Ponds and Lakes, Inland Pond and Lake Islands, Inland Stream and River Islands, Ocean Shoreline and Ocean Islands using TerraModeler functionality. Elevation values were assigned to all Inland streams and rivers using Photo Science proprietary software. All ground (ASPRS Class 2) LiDAR data inside of the collected inland 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. These points were moved from ground (ASPRS Class 2) to Ignored Ground (ASPRS Class 10). The breakline files were then translated to ESRI Shapefile format using ESRI conversion tools. Raster DEM Process: Using automated scripting routines within ArcMap, the ground (ASPRS Class 2) and bare water (USGS Class 14) were combined with the Hydro Flattened Breaklines (excluding the Ocean Shoreline and Ocean Island line types) to create the 1 meter DEM. Final DEM tiles were clipped to the project tile boundary to provide a seamless dataset. ERDAS IMG files were then created as the project deliverable. A manual QA review of the tiles was completed in ArcMap and Global Mapper to ensure full coverage with no gaps or slivers within the project area.
    • The NOAA Coastal Services Center (CSC) received the topographic files in .LAS format from USGS and the Maine Office of GIS. The classified .LAS files contained lidar elevation and intensity measurements. The data were received in UTM Zone 18N/19N, NAD83 coordinates and were vertically referenced to NAVD88 using the Geoid09 model. The vertical units of the data were meters. CSC performed the following processing for data storage and Digital Coast provisioning purposes: 1. The topographic .LAS files were compressed using LASTools' LASZip software. 2. The topographic .LAS files' classification scheme was shifted: Class 25 (Overlap Water) was changed to Class 15 (Empty), Class 30 (Overlap Bare Water) was changed to Class 16 (Empty). Class 11 (Witheld) was dropped from the .LAS files entirely. Please see the complete Classification Scheme listed in the Abstract section above. 3. The topographic .LAS files were converted from a Projected Coordinate System (UTM Zone 18N/19N) to a Geographic Coordinate system (NAD83). 4. The topographic .LAS files' horizontal units were converted from meters to decimal degrees. 5. The topographic .LAS files' were converted from orthometric NAVD88 to NAD83 ellipsoidal heights using Geoid09. 6. 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: 2013-11-26

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