| snippet:
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Delaware 1992 Orthophotography |
| summary:
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Delaware 1992 Orthophotography |
| accessInformation:
|
EarthData/PhotoScience Inc. |
| thumbnail:
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thumbnail/thumbnail.JPEG |
| typeKeywords:
|
["Data","Service","Image Service","ArcGIS Server"] |
| MinScale:
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1.5E8 |
| description:
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<DIV STYLE="text-align:Left;"><DIV><DIV><P STYLE="margin:0 0 0 0;"><SPAN><SPAN>Resolution: 1.0 Meter</SPAN></SPAN></P><P STYLE="margin:0 0 0 0;"><SPAN><SPAN>Bands: 3-band: G, R, NIR</SPAN></SPAN></P><P /><P STYLE="margin:0 0 0 0;"><SPAN><SPAN>DelDOT</SPAN></SPAN><SPAN /><SPAN><SPAN>Delivered as 172 Quarter-quads.</SPAN></SPAN><SPAN /><SPAN><SPAN>Each tile is 137 MB (TIF).</SPAN></SPAN><SPAN /><SPAN><SPAN>Scale: 1:12,000</SPAN></SPAN><SPAN /><SPAN><SPAN>SRS: NAD83 State Plane meters</SPAN></SPAN></P><P /><P STYLE="margin:0 0 0 0;"><SPAN><SPAN>The State of Delaware contracted with PhotoScience Inc. to develop 1-meter resolution color-infrared digital ortho-photos for the entire state. PhotoScience Inc. became Earth Data International. For more detailed information about the source data, contact EarthData (http://www.earthdata.com). Airphotos were taken in March, 1992 at a 1:12000 scale, digitized and georeferenced to Delaware State Plane coordinates (meters, North American Datum 1983).</SPAN></SPAN></P><P /><P STYLE="margin:0 0 0 0;"><SPAN><SPAN>Airphotos were taken in March, 1992, digitized and georeferenced to Delaware State Plane coordinates (meters, North American Datum 1983, based on GRS 1980 spheroid). The source data are 140 MB 24-bit color files for each of the 172 quarter-quads in Delaware.</SPAN></SPAN></P><P /><P STYLE="margin:0 0 0 0;"><SPAN><SPAN>To facilitate dissemination of these data, the Spatial Analysis Lab resampled the 172 DOQ's covering the state to UTM coordinates (meters, NAD 1983) at 5-meter resolution in 8-bit color, achieving initial file size reductions of almost 99 percent. The Spatial Analysis Lab used a nearest-neighbor (i.e. center-cell selection) resampling procedure which generates a high-contrast image with some blockiness in very small features. Each transformation used four 3.75-minute-interval reference points located near the corners of each image. Each resampled image is approximately 1210 x 1510 pixels, with a 10-pixel (50-meter) border cropped out to eliminate slight edge skewness resulting from the reprojection. Images still have at least 500 meters of edge overlap. Color palettes were brightened and adjusted for improved consistency using Adobe Photoshop. Sun glare has been masked out of water pixels in most coastal images in order to correct color palettes.</SPAN></SPAN></P><P /><P STYLE="margin:0 0 0 0;"><SPAN><SPAN>Cell resolution is exactly 5 x 5 meters. The original 1992 and 1997 series have differing degrees of positional error, and thus are not perfectly congruent. Earth Data used a larger set of ground control points to geo-reference the 1997 series, so these should have better positional acuracy.</SPAN></SPAN></P><P /><P STYLE="margin:0 0 0 0;"><SPAN><SPAN>Most images were brightened and contrast-enhanced using Adobe Photoshop. To reduce file size and eliminate sun glare, large water areas are masked to black.</SPAN></SPAN></P></DIV></DIV></DIV> |
| licenseInfo:
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<DIV STYLE="text-align:Left;"><DIV><DIV><P STYLE="margin:0 0 0 0;"><SPAN>Public Domain Information</SPAN></P></DIV></DIV></DIV> |
| catalogPath:
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|
| title:
|
Delaware 1992 Orthophotography |
| type:
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Image Service |
| url:
|
https://prt2epbfirstmap.dti.state.de.us:6443/arcgis/services/DE_Imagery/DE_Imagery_1992/ImageServer |
| tags:
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["Orthophotography","imagery","aerial photo","color infrared","Delaware","New Castle County","Kent County","Sussex County"] |
| culture:
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en-US |
| name:
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DE_Imagery_1992 |
| guid:
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|
| MaxScale:
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5000.0 |
| spatialReference:
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WGS_1984_Web_Mercator_Auxiliary_Sphere |