The 2013 Piscataqua Region Estuaries Partnership Orthoimagery dataset consists of orthophotography for the Piscataqua Region of New Hampshire
and southern Maine. Imagery was collected on August 24, 2013 at low tide. The Piscataqua Region covers the following area: two major estuaries
(the Great Bay Estuary and the Hampton-Seabrook Harbor); coastal waters within 0.5 miles of shore; and land in Rockingham (NH), Strafford (NH),
and York (ME) counties within 10 to 20 miles of the coast.
The 2013 Piscataqua Region Estuaries Partnership Orthoimagery produced orthophotos that are untiled (scanline), four band (R, G, B, NIR) GeoTIFF
images (with appropriate world file), with 1-foot ground sample distance resolution and a 2-foot spatial accuracy. The raw imagery was acquired
using the Intergraph Digital Mapping Camera (DMC) mounted on a fixed wing aircraft at an elevation of approximately 10,000 feet above ground.
Digital ortho-rectified images were created from the digital aerial imagery, aerotriangulation results, and a digital elevation model. An
orthoimage is a remotely sensed image data in which displacement of features in the image caused by terrain relief and sensor orientation have
been mathematically removed, thus it combines the image characteristics of a photograph with the geometric qualities of a map.
The orthophotography was generated by contractors for the Piscataqua Region Estuaries Partnership at the University of New Hampshire (Durham, New
Hampshire). Richard Crouse & Associates (Frederick, Maryland) acquired the raw aerial photographs. KAPPA Mapping, Inc. (Bangor, Maine) processed
the raw imagery to create the orthophotos and verify that quality assurance objectives were met.
Purpose:
The digital orthoimagery is both high resolution and spatially accurate, and can serve as a raster base image for mapping projects as well as a
data source to support the derivation of new raster and vector data sets.
Supplemental_Information:
Digital aerial imagery was obtained on August 24, 2013 using a large format Intergraph Digital Mapping Camera system (DMC) equipped with Airborne
GPS/IMU. A total of 9 flight lines with 468 frames were acquired in multispectral (RGB and NIR) 8 bits per band format. The imagery was acquired
with a 4.7244" (120 mm) focal length at an altitude of approximately 10,000' above mean terrain, to yield a raw pixel resolution of 1' (.3m)
suitable for photogrammetric mapping and orthophoto production. The leaf-on imagery was collected on August 24, 2013 under conditions free from
clouds and cloud shadows, smoke, fog, haze, light streaks, snow, ice on water bodies, flooding, and excessive soil moisture. The sun angle
threshold was between 25 and 50 degrees. At the time of the imagery collection: (1) water clarity in the Great Bay Estuary in the middle of the
study area was better than average; (2) wind speeds were <10 miles per hour; (3) no rainfall had been recorded for the preceding 7 days; and (4)
the tide was low (images collected within 2 hours of mean low water). The imagery consisted of panchromatic, red, blue, green, and near infrared
bands. Pan-sharpening was applied to transfer RGB and NIR values from the 20 micron sensor data to the 12 micron black and white images to produce
the 12 micron 4-band images. All 4 bands were used in the orthophoto production.
Data distribution tile: 5140' x 5100' (The corresponding tile index shapefile - PREP_Final_Tiles - is available from GRANIT.)
Images are being distributed in compressed, sid format. Geotiff versions are also available upon request.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20130824
Beginning_Time: 08119 EDST
Ending_Date: 20130824
Ending_Time: 1017 EDST
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -70.9292057191
East_Bounding_Coordinate: -70.9099952482
North_Bounding_Coordinate: 42.9332716929
South_Bounding_Coordinate: 42.9190455745
Keywords:
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: Aerial image
Theme_Keyword: Aerial photography
Theme_Keyword: Aerials
Theme_Keyword: Basemap
Theme_Keyword: Digital orthophoto
Theme_Keyword: Digital ortho
Theme_Keyword: Ortho
Theme_Keyword: Orthoimagery
Theme_Keyword: Orthophotography
Theme_Keyword: Ortho-rectified imagery
Place:
Place_Keyword_Thesaurus: None
Place_Keyword: Great Bay Estuary NH
Place_Keyword: Piscataqua Region
Place_Keyword: Hampton-Seabrook Estuary NH
Place_Keyword: Barrington NH
Place_Keyword: Dover NH
Place_Keyword: Durham NH
Place_Keyword: Exeter NH
Place_Keyword: Greenland NH
Place_Keyword: Hampton Falls NH
Place_Keyword: Hampton NH
Place_Keyword: Kensington NH
Place_Keyword: Lee NH
Place_Keyword: Madbury NH
Place_Keyword: New Castle NH
Place_Keyword: Newfields NH
Place_Keyword: Newington NH
Place_Keyword: Newmarket NH
Place_Keyword: North Hampton NH
Place_Keyword: Portsmouth NH
Place_Keyword: Rochester NH
Place_Keyword: Rollinsford NH
Place_Keyword: Rye NH
Place_Keyword: Seabrook NH
Place_Keyword: Somersworth NH
Place_Keyword: South Hampton NH
Place_Keyword: Stratham NH
Place_Keyword: Berwick ME
Place_Keyword: Eliot ME
Place_Keyword: Kittery ME
Place_Keyword: South Berwick ME
Place_Keyword: York ME
Place_Keyword: Amesbury MA
Place_Keyword: Newburyport MA
Place_Keyword: Salisbury MA
Temporal:
Temporal_Keyword_Thesaurus: None
Temporal_Keyword: Summer 2013
Access_Constraints: None
Use_Constraints:
The Piscataqua Region Estuaries Partnership (PREP) makes this information available to enhance public knowledge and promote education. PREP also
retains the right to make changes to the data without prior notice. Neither PREP, nor any of its employees, contractors, or subcontractors, make any
warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any data, nor represent
that its use would not infringe on privately owned rights. The data are provided with the understanding that they are not guaranteed to be usable, timely,
accurate, or complete, and it should not be used for navigational purposes. PREP assumes no liability, any damages or loss of any kind that might arise from
the use of, misuse of, or the inability to use these data. PREP assumes no liability for any damages or loss of any kind caused by any errors or omissions in
the data. All data are distributed "as is," without warranties of any kind, either express or implied, and subject to the terms and conditions stated in this
disclaimer.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Earth Systems Research Center
Contact_Person: GRANIT Database Manager
Contact_Position: GRANIT Database Manager
Contact_Address:
Address_Type: mailing and physical address
Address: Morse Hall, University of New Hampshire
City: Durham
State_or_Province: NH
Postal_Code: 03824
Country: US
Contact_Voice_Telephone: 603-862-1792
Contact_Facsimile_Telephone: 603-862-0188
Contact_Electronic_Mail_Address: granit@unh.edu
Hours_of_Service: 8:30AM-5PM, EST
Contact_Instructions: Email is preferred.
Data_Set_Credit:
Orthophotos were produced for Piscataqua Region Estuaries Partnership (PREP) . Subcontractor included Richard Crouse and Associates for
aerial imagery acquisition.
Native_Data_Set_Environment:
Microsoft Windows Vista Version 6.1 (Build 7601) Service Pack 1; ESRI ArcCatalog 9.3.1.4000
Data_Quality_Information:
Logical_Consistency_Report:
Standard practice dictates that all photogrammetric data be field checked prior to use.
Cloud_Cover: 0%
Completeness_Report: Data are complete for the tile.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Contact Piscataqua Region Estuaries Partnership for NSSDA-compliant Accuracy Report.
Low tide, leaf-on 4-band imagery with a 0.95' nominal ground sample distance (GSD) was acquired with an Intergraph Z/I Imaging DMC-I digital mapping camera.
The photo block consisted of 10 flight lines with a total of 468 images using 60% forward-lap and 30% sidelap. Airborne GPS (ABGPS) and inertial measurement
unit (IMU) data were simultaneously collected with the imagery. The ABGPS/IMU data were post-processed to provide exposure center positions and rotations to
supplement the ground control in the aerotriangulation phase.
Flying and post-processing were done by Richard Crouse & Associates, Inc.
Ground control was acquired from three sources:
1. The Maine Orthophoto Program's 2012 campaign. Surveyed by Shyka, Sheppard & Garster for the prime contractor, Woolpert, Inc.
2. The New Hampshire Orthophoto Program's 2010 campaign. Surveyed by James W. Sewall Company for the prime contractor, Photo Science, Inc.
3. KAPPA's in-house photo control originally established by Bradstreet Consultants Inc (BCI), and acquired by KAPPA Mapping with many of BCI's assets.
The aerotriangulation (AT) task combined the camera calibration, image measurements, the post-processed ABGPS/IMU positions/rotations, and 40 well
distributed ground control points in a simultaneous least-squares adjustment (bundle adjustment) producing the final adjusted image positions and
rotations for all of the non-water images. 28 points were full horizontal/vertical control, and 12 points were vertical control only. Images that
were entirely water or mostly water used the post-processed ABGPS/IMU positions and rotations. KAPPA reviewed all results.
The Digital Elevation Model (DEM) was assembled by KAPPA Mapping Inc. from freely available existing data and was developed for orthophotography purposes
only. KAPPA used the National Elevation Dataset (NED) from USGS which was developed from the LiDAR for the Northeast program along the coastline and most
of the project area. Small areas not covered by the LiDAR for the Northeast program were filled in with 1/3 arcsecond DEM data, which was determined to be
the best freely available data. Areas covered by 1/3 arcsecond DEM include:
(A) Upper left=357046.095,43618.180; Lower right=358303.562, 42122.025.
(B) Upper left=367195.824, 45392.070; Lower right=370205.595, 42452.160.
(C) Upper left=381625.770, 67859.840; Lower right=383765.210, 64864.620.
(D) Upper left=368173.490, 83080.975; Lower right=383603.660, 76584.060.
CORPSCON version 6.0.1 software was used to re-project these NAD83 positions to the New Hampshire State Plane Coordinate System NAD83 using units of USFT.
The NAVD88 orthometric heights were converted at the same time from meters to USFT. For quality control, KAPPA visually inspected the merged DEM data,
to ensure that there were no discontinuities between the data sources.
Digital 4-band (R,G,B, NIR) color ortho-rectified images were created from the following raw data sources: digital aerial imagery, aerotriangulation
results, Digital Elevation Model (DEM). The individual images were orthorectified using Cardinal Systems's Vr orthorectification software. The
orthorectification process used a cubic convolution algorithm. Images were reviewed to select images that minimized building leans and shadows.
The orthorectified images were mosaicked into a seamless composite using OrthoVista 5.5 software. Mosaicking occurred along sharp linear features where
possible and linear feathering was used to blend the images. This software package also provided tools for radiometrically balancing of the images, to
ensure image consistency and enhancement across flight lines.
Mosaicking occurred along linear features and were individually inspected to ensure that seam lines did not go through buildings, etc. In addition, each
image was individually inspected for pleasing and consistent color balancing. Once the images were color corrected and mosaicked, they were tiled to a
layout that has tile sizes of approximately 100 MB for untiled GeoTIFF images with a final pixel resolution of 1.0 foot.
Process_Date: 2013
Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Pixel
Row_Count: 5140
Column_Count: 5100
Vertical_Count: 1
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: row and column
Coordinate_Representation:
Abscissa_Resolution: 1.000000
Ordinate_Resolution: 1.000000
Planar_Distance_Units: survey feet
Map_Projection:
Map_Projection_Name: Transverse Mercator
Transverse_Mercator:
Scale_Factor_at_Central_Meridian: 0.999967
Longitude_of_Central_Meridian: -71.666667
Latitude_of_Projection_Origin: 42.500000
False_Easting: 984250.000000
False_Northing: 0.000000
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: Geodetic Reference System 80
Semi-major_Axis: 6378137.000000
Denominator_of_Flattening_Ratio: 298.257222
Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Earth Systems Research Center
Contact_Person: GRANIT Database Manager
Contact_Position: GRANIT Database Manager
Contact_Address:
Address_Type: mailing and physical address
Address: Morse Hall, University of New Hampshire
City: Durham
State_or_Province: NH
Postal_Code: 03824
Country: US
Contact_Voice_Telephone: 603-862-1792
Contact_Facsimile_Telephone: 603-862-0188
Contact_Electronic_Mail_Address: granit@unh.edu
Hours_of_Service: 8:30AM-5PM, EST
Distribution_Liability:
Digital data in NH GRANIT represent the efforts of the
contributing agencies to record information from the cited
source materials. Earth Systems Research Center, under
contract to the NH Office of Energy and Planning, and in
consultation with cooperating agencies, maintains a
continuing program to identify and correct errors in these
data. OEP, CSRC, and the cooperating agencies make no claim
as to the validity or reliability or to any implied uses of
these data.
