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2016 CT Coastal Orthophotos

Frequently-asked questions:

What does this data set describe?

2016 CT Coastal Orthophotos

Project: NOAA 2016 Multispectral Coastal Imagery Project – Connecticut Shoreline Orthoimagery Contract No. EA133C11CQ0010 Reference No. NCNP0000-16-01163 Woolpert Order No. 76783 CONTRACTOR: Woolpert, Inc. This project represents the collection of high resolution 4-band (RGB-IR) orthoimagery covering approximately 876 square miles at a 6” (0.5-foot) ground sample distance (GSD). The 4-band (RGB-IR) digital orthophotos will be delivered as 16-bit red, green, blue and infrared bands in uncompressed GeoTIFF format. The area of interest (AOI) was flown between July 26, 2016 and August 24, 2016 (specifically July 26, 2016; July 27, 2016; July 30, 2016; August 3, 2016, August 4, 2016; August 5, 2016, August 6, 2017; August 8, 2016; August 9, 2016; August 24, 2016). This area includes: all land areas within one-thousand (1,000) feet of Mean High Water (MHW) and within one-thousand (1,000) feet of state-regulated tidal wetlands; offshore areas at least two-thousand (2,000) feet waterward of either the mainland or island land masses in order to clearly depict the interface between the shore and coastal waters; all offshore islands within the borders of the State of Connecticut including: Goose Island and Falkner Island (offshore of Branford); Calf Islands and Great Captain Island (offshore of Greenwich); Norwalk Islands (offshore of Norwalk); Thimble Islands (offshore of Branford); Sandy Point (offshore of Stonington); all islands in the Connecticut part of Fishers Island Sound; and the Connecticut River from Long Island Sound to the Connecticut/Massachusetts state line.

Supplemental information:
Imagery was collected during Mean Low Tide - Mean Lower Low Tide +/- 1 hours. Imagery acquisition occurred while no snow is on the ground, rivers are within their channels at or below normal levels, when the sky is sufficiently clear of clouds, smoke and atmospheric haze. 

  1. How should this data set be cited?

    NOAA Office for Coastal Management In partnership with CT Department of Energy & Environmental Protection Office of Long Island Sound Programs, 20170710, 2016 CT Coastal Orthophotos.

  2. What geographic area does the data set cover?

    Bounding coordinates:
    West: -73.666797
    East: -73.645500
    North: 40.992018
    South: 40.970719

  3. What does it look like?

  4. Does the data set describe conditions during a particular time period?

    Calendar date: 20160808
    Calendar date: 20160824
    Currentness reference:
    ground condition

  5. What is the general form of this data set?

    Geospatial data presentation form: remote-sensing image

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a Raster data set. It contains the following raster data types:
      • Dimensions 15400 x 11600, type Pixel

    2. What coordinate system is used to represent geographic features?

      The map projection used is NAD 1983 StatePlane Connecticut FIPS 0600 Feet.

      Projection parameters:
      NAD 1983 StatePlane Connecticut FIPS 0600 Feet
      Standard parallel: 41.2
      Standard parallel: 41.86666666666667
      Longitude of central meridian: -72.75
      Latitude of projection origin: 40.83333333333334
      False easting: 999999.999996
      False northing: 499999.999998

      Planar coordinates are encoded using row and column.
      Abscissae (x-coordinates) are specified to the nearest 0.5.
      Ordinates (y-coordinates) are specified to the nearest 0.5.
      Planar coordinates are specified in foot_us.

      The horizontal datum used is D North American 1983.
      The ellipsoid used is GRS 1980.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.

  7. How does the data set describe geographic features?

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Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

    State of Connecticut – Department of Housing Community Development Block Grant – Disaster Recovery October 1 – December 31, 2016, NOAA Office for Coastal Management, CT Department of Energy & Environmental Protection Land & water resource Division, Woolpert, LLC

  3. To whom should users address questions about the data?

    Kevin P. O’Brien
    Land & Water Resources Division - Coastal Resources Section Bureau of Water Protection and Land Reuse Connecticut Department of Energy and Environmental Protection
    79 Elm Street
    Hartford, CT 06106-5127

    860.424.3432 (voice)
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Why was the data set created?

The natural color orthoimagery was created to support NOAA Office for Coastal Management in partnership with CT Department of Energy & Environmental Protection (CTDEEP) Office of Long Island Sound Programs.

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How was the data set created?

  1. Where did the data come from?

  2. What changes have been made?

    Date: 20160726 (change 1 of 1)
    The Leica ADS80-SH81/82 Airborne Digital Sensor is a push-broom geometry sensor, collecting 12-bit data with 12,000 pixel swath coverage with up to a 5-centimeter spatial resolution. The sensor is capable of collecting multiple spectral bands and angles simultaneously. Leica’s ADS80 collects seven bands of imagery simultaneously: three panchromatic CCD lines capture information in the forward, nadir and backward views from the aircraft, while four multispectral lines capture data in the red, green, blue, and near color infrared band. The imagery for this task order was acquired using the Leica ADS80-SH81/82 multispectral scanner. The ADS80-SH81/82 utilizes the Leica’s IPAS20 direct positioning and orientation system that is based on airborne GPS and inertial measurement unit (IMU) technology. The IPAS20 data were reduced using Leica’s IPAS Pro v1.3 software package. All of the source imagery was processed using the Leica XPRO (V5.2) software package. This package provides the capability to perform digital image processing, aerial triangulation, and image rectification. The strips of imagery were ortho rectified to client provided lidar digital elevation model (DEM) data. The individual rectified strips of ortho rectified imagery were then mosaicked together to form a seamless imagery database over the entire task order area using the OrthoVista software (V4.5) by Inpho GmbH. The final digital orthophoto imagery (DOI) were extracted using OrthoVista.

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How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?

  2. How accurate are the geographic locations?

    Woolpert utilized 39 ground control points as QA/QC test points to validate the horizontal accuracy of the orthoimagery.  The results of the assessment indicated a horizontal accuracy of the following: NSSDA Accuracy of 1.93-feet at a 95% Confidence Level.

  3. How accurate are the heights or depths?

  4. Where are the gaps in the data? What is missing?

    The imagery data is visually inspected for completeness to ensure that there are no void areas or missing data.

  5. How consistent are the relationships among the observations, including topology?

    All formatted data cover the entire area specified for this project and are validated using a combination of commercial imagery processing software, GIS software, and proprietary programs to ensure proper formatting and loading prior to delivery.

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How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access constraints: None
Use constraints:
While efforts have been made to ensure that these data are accurate and reliable within the state of the art, NOAA, cannot assume liability for any damages, or misrepresentations, caused by any inaccuracies in the data, or as a result of the data to be used on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty. We do request that you credit the National Oceanic and Atmospheric Administration (NOAA) when you use these photos in a report, publication, or presentation.

Distributor 1 of 1

  1. Who distributes the data set?

    National Oceanic and Atmospheric Administration (NOAA)
    2234 South Hobson Avenue
    Charleston, SC 29405

    843-740-1200 (voice)

  2. What's the catalog number I need to order this data set?


  3. What legal disclaimers am I supposed to read?

    The information contained in these data is dynamic and may change over time. The data are not better than the original sources from which they were derived. It is the responsibility of the data user to use the data appropriately and within the limitations of the data for which it was requested and prepared, in general, and these data in particular. The related graphics are intended to aid the data user in acquiring relevant data. It is not appropriate to use the related graphics as data. Woolpert gives no warranty, expressed or implied, as to the accuracy, reliability, or completeness of these data. It is strongly recommended that these data are directly acquired from a Woolpert server, and not indirectly through other sources which may have changed the data in some way. Although these data have been processed successfully upon Woolpert’s computer system, no warranty, expressed or implied, is made regarding the utility of the data on another system, or for general or scientific purposes; nor shall the act of distribution constitute any such warranty. This disclaimer applies both to individual use of the data and aggregate use with other data.

  4. How can I download or order the data?

  5. Is there some other way to get the data?

  6. What hardware or software do I need in order to use the data set?

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Who wrote the metadata?

Last modified: 20170710

Metadata author:
National Oceanic and Atmospheric Administration (NOAA)
2234 South Hobson Avenue
Charleston, SC 29405

843-740-1200 (voice)

Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata(FGDC-STD-001-1998)

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