| snippet:
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Six thousand four hundred three photos were aerotriangulated to support the orthophotography production for Will County, Illinois. Digital aerial exposures, Airborne Global Positioning System (ABGPS) exposure station data, and ground check point data were provided by Aero-Metric. The project was referenced to the North American Datum of 1983 HARN, Illinois State Plane, North Zone and to the North American Vertical Datum of 1988 (NAVD88).The digital images (12 microns), ABGPS data, ground check point data, and camera data were used as inputs to the Zeiss/Intergraph ImageStation Automatic Triangulation (ISAT) softcopy program. ISAT correlated image points and aerotriangulated the block of images to create exposure station exterior orientations. The twenty seven ground check points were manually measured on the imagery. These ground check points were included in the aerotriangulation adjustment as unconstrained points for absolute ground location verification. In the final adjustment, the ground points were weighted as ground control. An "index" of 1.1' was subtracted from the elevations of the ABGPS exposure stations to compensate for the vertical bias inherent in ABGPS.The scale of the aerial imagery is 1:9156. The calibrated focal length for all photos is 120.000 mm. The dates of the photography are April 2, 5 & 14, 2004. |
| summary:
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Six thousand four hundred three photos were aerotriangulated to support the orthophotography production for Will County, Illinois. Digital aerial exposures, Airborne Global Positioning System (ABGPS) exposure station data, and ground check point data were provided by Aero-Metric. The project was referenced to the North American Datum of 1983 HARN, Illinois State Plane, North Zone and to the North American Vertical Datum of 1988 (NAVD88).The digital images (12 microns), ABGPS data, ground check point data, and camera data were used as inputs to the Zeiss/Intergraph ImageStation Automatic Triangulation (ISAT) softcopy program. ISAT correlated image points and aerotriangulated the block of images to create exposure station exterior orientations. The twenty seven ground check points were manually measured on the imagery. These ground check points were included in the aerotriangulation adjustment as unconstrained points for absolute ground location verification. In the final adjustment, the ground points were weighted as ground control. An "index" of 1.1' was subtracted from the elevations of the ABGPS exposure stations to compensate for the vertical bias inherent in ABGPS.The scale of the aerial imagery is 1:9156. The calibrated focal length for all photos is 120.000 mm. The dates of the photography are April 2, 5 & 14, 2004. |
| extent:
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[[-88.2761028792562,41.192222652156],[-87.506122693999,41.7458936775817]] |
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thumbnail/thumbnail.png |
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1.7976931348623157E308 |
| typeKeywords:
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["Data","Service","Map Service","ArcGIS Server"] |
| description:
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|
| licenseInfo:
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|
| catalogPath:
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|
| title:
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Orthos_2004_6IN_WM |
| type:
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Map Service |
| url:
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|
| tags:
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["2004","Aerial","Orthoimagery"] |
| culture:
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en-US |
| name:
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Orthos_2004_6IN_WM |
| guid:
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526CABAC-5149-4163-BDA5-725384F384BB |
| minScale:
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0 |
| spatialReference:
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WGS_1984_Web_Mercator_Auxiliary_Sphere |