The data set contains 1:12,000-scale, 1-meter resolution,
black & white orthophotoquads, compressed from TIFFs to
MrSID format.
Orthophotos combine the image characteristics of a
photograph with the geometric qualities of a map. The
primary digital orthophotoquad (DOQ) is a 1-meter ground
resolution, quarter-quadrangle (3.75-minutes of latitude by
3.75-minutes of longitude) image. The geographic extent of
the DOQ is equivalent to a standard quarter-quadrangle.
The normal orientation of data is by lines (rows) and
samples (columns). Each line contains a series of pixels
ordered from west to east with the order of the lines
from north to south. The radiometric image brightness
values are stored as 256 gray levels ranging from 0 to 255.
While the original USGS format for distribution of DOQs
is TIFF images, GRANIT distributes the data in both
MrSID and the original TIFF formats.
The metadata record provided with the DOQ contains
a wide range of descriptive information including format
source information, production instrumentation and dates,
and data to assist with displaying and georeferencing the
image. In addition to this file, the original USGS header
file, including source and coordination information, is
available upon request. However, please note that it will
not reflect processing completed at Complex Systems Research
Center (see DATA_QUALITY_INFORMATION below).
Purpose:
DOQ's serve a variety of purposes, from interim maps to
field references for earth science investigations and
analysis. The DOQ is useful as a layer of a geographic
information system and as a tool for revision of digital
line graphs and topographic maps.
Supplemental_Information:
Data distribution tile: quarter of a 7.5-minute quadrangle
(e.g. 3.75 x 3.75 minutes) or full 7.5-minute quadrangle
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 041398
Currentness_Reference: ground condition
Status:
Progress: In work
Maintenance_and_Update_Frequency: Irregular
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -72.437
East_Bounding_Coordinate: -72.375
North_Bounding_Coordinate: 43.000
South_Bounding_Coordinate: 42.938
Keywords:
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: DOQ
Theme_Keyword: DOQQ
Theme_Keyword: digital orthophoto
Theme_Keyword: digital orthophotoquad
Theme_Keyword: digital image map
Theme_Keyword: aerial photograph
Theme_Keyword: rectified photograph
Theme_Keyword: rectified image
Theme_Keyword: orthophoto
Theme_Keyword: quarter-quadrangle orthophoto
Theme_Keyword: 1-meter orthophoto
Theme_Keyword: 3.75- x 3.75-minute orthophoto
Theme_Keyword: 7.5- x 7.5-minute orthophoto
Place:
Place_Keyword_Thesaurus: None
Place_Keyword: United States
Place_Keyword: Northeast
Place_Keyword: New England
Place_Keyword: New Hampshire
Place_Keyword: SPOFFORD
Access_Constraints:
Acknowledgement of GRANIT and the US Geological Survey
would be appreciated in products derived from these data.
Use_Constraints: Not for legal use.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Complex Systems Research Center
During photographic reproduction of the source photography,
limited analog dodging is performed to improve image
quality. Analog dodging consists of holding back light from
certain areas of the sensitized photographic material to
avoid overexposure. The diapositive is inspected to insure
clarity and radiometric uniformity. Diapositive image
brightness values are collected with a minimum of image
quality manipulation. Image brightness values may deviate
from brightness values of the original imagery due to image
value interpolation during the scanning and rectification
processes. Radiometry is verified by visual inspection of
the digital orthophoto quadrangle with the original
unrectified image to determine if the digital orthophoto
has the same or better image quality as the original
unrectified input image. Slight systematic radiometric
differences can be detected between adjacent DOQ files due
primarily to differences in source photography capture
dates and sun angles of aerial photography along flight
lines. These differences can be observed in an image's
general lightness or darkness when compared to adjacent DOQ
file coverages
Logical_Consistency_Report: Not Applicable
Completeness_Report:
All DOQ imagery is visually inspected for completeness to
ensure that no gaps or image misplacement exist in the
3.75' image area. DOQ images may be derived by mosaicking multiple
source images, in order to insure complete coverage. All DOQ's are
cloud free within the 3.75' image area. Source photography is
leaf-off in deciduous vegetation regions.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Refer to the USGS website <URL:http://www.usgs.gov> for
information about horizontal positional accuracy. Note
that the GRANIT image is re-cast onto the NH State Plane
coordinate system.
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
Refer to the USGS website <URL:http://www.usgs.gov> for
information about vertical positional accuracy. Note
that the GRANIT image is re-cast onto the NH State Plane
coordinate system.
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: US Geological Survey
Publication_Date: Unknown
Title: Digital Elevation Model
Geospatial_Data_Presentation_Form: map
Publication_Information:
Publication_Place: Reston, VA
Publisher: US Geological Survey
Type_of_Source_Media: cartridge tape
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 19880805
Ending_Date: Present
Source_Currentness_Reference: ground condition
Source_Citation_Abbreviation: DEM1
Source_Contribution:
Elevation data in the form of an ortho-DEM regridded to
user-specified intervals and bounds.
Date of the camera calibration associated with the
source photography.
Source_Citation_Abbreviation: CAMERA_INPUT
Source_Contribution: Camera calibration parameters.
Source_Information:
Source_Citation:
Citation_Information:
Originator: US Geological Survey
Publication_Date: Unknown
Title: Digital Orthophoto Quarterquads
Edition: 1
Geospatial_Data_Presentation_Form: map
Publication_Information:
Publication_Place: Reston, VA
Publisher: US Geological Survey
Source_Scale_Denominator: 12000
Type_of_Source_Media: CD-ROM
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: Unknown
Ending_Date: Present
Source_Currentness_Reference: Publication Date
Source_Citation_Abbreviation: USGSDOQ
Source_Contribution: DOQ's in standard USGS referencing system in TIFF format.
Source_Information:
Source_Citation:
Citation_Information:
Originator: Complex Systems Research Center
Publication_Date: Unknown
Title: Quarter Quad Boundaries
Edition: 1
Geospatial_Data_Presentation_Form: map
Publication_Information:
Publication_Place: Durham, NH
Publisher: Complex Systems Research Center, UNH
Source_Scale_Denominator: 12000
Type_of_Source_Media: digital
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: Unknown
Ending_Date: Present
Source_Currentness_Reference: Publication Date
Source_Citation_Abbreviation: QQBOUNDS
Source_Contribution: USGS quarter-quad boundaries
Process_Step:
Process_Description:
The production procedures, instrumentation, hardware and
software used in the collection of standard USGS DOQ's
vary depending on systems used at the contract,
cooperator or USGS production sites. The majority of DOQ
datasets are acquired through government contract. The
process step describes, in general, the process used in
the production of standard USGS DOQ data sets.
The rectification process requires, as input, a user
parameter file to control the rectification process, a
digital elevation model (DEM1) gridded to user specified
bounds, projection, zone, datum and X-Y units, a scanned
digital image file (PHOTO1) covering the same area as
the DEM, ground X-Y-Z point values (CONTROL_INPUT) and
their conjugate photo coordinates in the camera
coordinate system, and measurements of the fiducial
marks (CAMERA_INPUT) in the digitized image.
The camera calibration report (CAMERA_INPUT) provides
the focal length of the camera and the distances in
millimeters from the camera's optical center to the
camera's 8 fiducial marks. These marks define the frame
of reference for spatial measurements made from the
photograph. Ground control points (CONTROL_INPUT)
acquired from ground surveys or developed in
aerotriangulation, are third order class 1 or better,
and meet National Map Accuracy Standard (NMAS) for
1:12,000-scale. Ground control points are in the
Universal Transverse Mercator or the State Plane
Coordinate System on NAD83. Horizontal and vertical
residuals of aerotriangulated tie-points are equal to or
less than 2.5 meters. Standard aerotriangulation
passpoint configuration consists of 9 ground control
points, one near each corner, one at the center near
each side and 1 near the center of the photograph, are
used. The conjugate positions of the ground control
points on the photograph are measured and recorded in
camera coordinates.
The raster image file (PHOTO_1) is created by scanning
an aerial photograph film diapositive with a precision
image scanner. An aperture of approximately 25 to 32
microns is used, with an aperture no greater than 32
microns permitted. Using 1:40,000-scale photographs, a
25-micron scan aperture equates to a ground resolution
of 1-meter. The scanner converts the photographic image
densities to gray scale values ranging from 0 to 255 for
black and white photographs. Scan files with ground
resolution less than 1 meter or greater than 1 meter but
less than 1.28 meters are resampled to 1 meter.
The principal elevation data source (DEM1) are standard
DEM datasets from the National Digital Cartographic Data
Base (NDCDB). DEM's that meet USGS standards are also
produced by contractors to fulfill DOQ production
requirements and are subsequently archived in the NDCDB.
All DEM data is equivalent to or better than USGS DEM
standard level 1. The DEM used in the production of
DOQ's generally has a 30-meter grid post spacing and
possesses a vertical RMSE of 7-meters or less. A DEM
covering the extent of the photograph is used for the
rectification. The DEM is traversed from user-selected
minimum to maximum X-Y values and the DEM X-Y-Z values
are used to find pixel coordinates in the digitized
photograph using transformations mentioned above. For
each raster image cell subdivision, a brightness or
gray-scale value is obtained using nearest neighbor,
bilinear, or cubic convolution resampling of the scanned
image. The pixel processing algorithm is indicated in
the header file . An inverse transformation relates the
image coordinates referenced to the fiducial coordinate
space back to scanner coordinate space. For those areas
for which a 7.5-minute DEM is unavailable and relief
differences are less than 150 feet, a planar-DEM
(slope-plane substitute grid) may be used.
Rectification Process: The photo control points and
focal length are iteratively fitted to their conjugate
ground control points using a single photo space
resection equation. From this mathematical fit is
obtained a rotation matrix of constants about the three
axes of the camera. This rotation matrix can then be
used to find the photograph or camera coordinates of any
other ground X-Y-Z point. Next a two dimensional fit is
made between the measured fiducial marks on the
digitized photograph and their conjugate camera
coordinates. Transformation constants are developed from
the fit and the camera or photo coordinates are used in
reverse to find their conjugate pixel coordiates on the
digitized photograph.
Quality Control: All data is inspected according to a
quality control plan. DOQ contractors must meet DOQ
standards for attribute accuracy, logical consistency,
and data completeness.
Once acquired by Complex Systems Research Center, the
USGSDOQs are processed as follows:
- Convert image to grid (ARC/INFO imagegrid)
- Project grid from UTM meters (zone 18, or 19), NAD83
to NH State Plane feet (Zone 4676), NAD83
- Clip the projected grid to quarter-quad boundaries
using QQBOUNDS, thereby eliminating any overlap in
the image areas.
- Convert grid to TIFF image (ARC/INFO gridimage
with no compression)
- Convert TIFF image to geo-referenced MrSID with
1:20 encoding ratio
Process_Date: 20001101
Source_Produced_Citation_Abbreviation: Version 1
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Organization: Complex 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
Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name: State Plane Coordinate System 1983
State_Plane_Coordinate_System:
SPCS_Zone_Identifier: New Hampshire
Transverse_Mercator:
Scale_Factor_at_Central_Meridian: 0.999967
Longitude_of_Central_Meridian: -71.666667
Latitude_of_Projection_Origin: 42.500000
False_Easting: 300000.000000
False_Northing: 0.000000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: Row and column
Coordinate_Representation:
Abscissa_Resolution: 3.28
Ordinate_Resolution: 3.28
Planar_Distance_Units: Feet
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: GRS 80
Semi-major_Axis: 6378137.0000000
Denominator_of_Flattening_Ratio: 298.26
Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview:
For DOQ's from panchromatic sources, each pixel contains an
8-bit gray-scale value between 0-255. A value of 0
represents the color black while a value of 255 represents
the color white. All values between 0 and 255 are
represented as a shade of gray varying from black to white.
Contact_Organization: Complex 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
Resource_Description: 98doq173ne - 1998 Digital Orthophoto Quadrangle for Quad 173NE
Distribution_Liability:
Digital data in NH GRANIT represent the efforts of the
contributing agencies to record information from the cited
source materials. Complex Systems Research Center, under
contract to the NH Office of State Planning, and in
consultation with cooperating agencies, maintains a
continuing program to identify and correct errors in these
data. OSP, CSRC, and the cooperating agencies make no claim
as to the validity or reliability or to any implied uses of
these data.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: MrSID
Transfer_Size: 2.5 MB (quarter quad tile)
Digital_Transfer_Option:
Offline_Option:
Offline_Media: CD-ROM
Recording_Format: MrSID
Compatibility_Information:
Requires MrSID extension in Arc8.x or ArcView 3.x. For
non-ESRI users, a free MrSID viewer may be
downloaded from URL:<http://www.lizardtech.com>
Fees:
No charge when downloaded through the Internet. Statewide
DOQ's are also available on pre-packaged CD/ROMs for $200 (4 CD
set). The fee for custom orders on CD/ROM is $100/CD.
Ordering_Instructions:
Email GRANIT (granit.sr.unh.edu) or order from web site
(www.granit.sr.unh.edu)
Metadata_Reference_Information:
Metadata_Date: 20020911
Metadata_Review_Date: 20020911
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Complex 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
Metadata_Standard_Name: FGDC CSDGM
Metadata_Standard_Version: FGDC-STD-001-1998
Generated by mp version 2.8.13 on Thu Dec 13 10:07:14 2007
