Connecticut 1965 Aerial Photo Center Point Index is a photo index for the 1965 Aerial Survey of Connecticut with approximate center point locations for each 1965 aerial photograph. Attributes for each point feature include flight line, photo number, and index map sheet number information. The Connecticut 1965 Aerial Survey is a set of non-rectified black and white aerial photo prints that may be used for stereoscopic viewing. Individual photo prints from the Connecticut 1965 Aerial Photography Survey are available from State Archives at the Connecticut State Library, 231 Capitol Avenue, Hartford, Connecticut 06106. Dates of the photography are March and April 1965. Map scale of photography is approximately 1:18,000 (1 inch = 1,500 feet). Size of prints is 9 inches x 9 inches. Photo index sheets printed at 1:63,360 scale. The non-rectified photos are also available in image format from the Connecticut State Library. The images are not geo-referenced or orthorectified.
Use this photo index to identify 1965 aerial photos by flight line and photo number on file at the Connecticut State Library, 231 Capitol Avenue, Hartford, Connecticut 06106.
To order printed copies of individual 1965 aerial photos, contact Keystone Aerial Surveys, Inc. PO Box 21059, Philadelphia, Pennsylvania, 19114-0559, telephone 215-677-3119.
Date of photography
None. No restrictions or legal prerequisites for using the data after access is granted. The data is suitable for use at appropriate scale. When printing this data on a map or using it in a software application, analysis, or report, please acknowledge the State of Connecticut, Department of Environmental Protection as the source for this information. For example, include the following data source description when printing this layer on a map: Aerial Photo Index - From the Connecticut 1965 Aerial Photo Center Point Index layer, compiled and published by CT DEP.
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All attributes have valid values. All values were visually inspected for accuracy and comparison with the data sources (index map sheets). Note a series of 19 photos exists between flight lines 38 and 39. The compiler attributed these photos wit FLIGHTLINE values encode as 0 (zero) because a flight line number for these photos was not depicted on the index map sheet. It appears these photos were taken to fill in a section not covered by flight lines 38 and 89.
Point features conform to the following topological rules. Points are single part. There are no duplicate points. Points do not overlap. Establishment of logical consistency was performed by the State of Connecticut, Department of Environmental Protection using ESRI ArcGIS software to manually create and control feature topology in geodatabase format. No automated procedures or tests were performed to guarantee desired topology other than visual inspection.
The completeness of the data reflects the content of the data sources, which are the published index maps for the Connecticut 1965 Aerial Photography Survey, which are available from State Archives at the Connecticut State Library, 231 Capitol Avenue, Hartford, Connecticut 06106. The Connecticut State Library holds several statewide aerial photograph collections and additional smaller collections. Information from the Connecticut State Library about the 1965 Aerial Photography Survey: Record Group 89: Records of the Department of Transportation . Dates of photography are March and April 1965. Photographed by Keystone Aerial Surveys, Inc., for the Public Works Department. Scale of photography is approximately 1:18,000 (1 inch = 1,500 feet). Size of prints 9 inches x 9 inches. Scale of index 1:63,360. To order printed copies of individual 1965 aerial photos, contact Keystone Aerial Surveys, Inc. PO Box 21059, Philadelphia, Pennsylvania, 19114-0559, telephone 215-677-3119.
The horizontal positional accuracy of this data is unknown. Spot check comparisons of these center point locations to the centers of the corresponding photo prints suggests they are positioned within 500 to 1,500 feet of their true location.
Includes the 20 index maps for the Connecticut 1965 Aerial Photo Survey produced by Keystone Aerial Surveys, Inc. Measuring approximately 20 inches by 24 inches in size, each index map is printed at 1:63,360-scale, showing flight line and photo number in the upper left hand corner of each photo.
Includes images of the 20 printed index maps in TIFF format georeferenced to the Connecticut State Plane Coordinate System, NAD 83. These georeferenced images are on file at CT DEP. Each digital index map is comprised of three files: a TIFF image file, a TIFF world file, and an auxilary file that specifies the image is georeference to the Connecticut State Plane Coordinate System, North American Datum of 1983. For example, the digital index for Sheet 1 is comprised the following files: index1965sheet01.aux, index1965sheet01.tfw, and index1965sheet01.tif. There are 20 sets of files like this; one set for each index sheet.
A point feature class that depicts the upper left corner location of each 1965 aerial photo. Photo_Index_1965_Upper_Left is in GeoDatabase Feature Class format.
A point feature class that depicts the approximate center point location of each 1965 aerial photo. Photo_Index_Center is in GeoDatabase Feature Class format.
Create Digital Index Maps - Scanned the printed index maps at a 2 color (black and white) 1 bit per pixel, 400 dpi resolution in TIFF format (in order to reduce the cost of scanning and limit image file size). Each scanned image was subsequently georeferenced to 1990 digital orthophotos using 3 to 4 control points. Related to the unknown horizontal accuracy of the individual photos upon which each index map is based (the original photos are not in digital format and not individually georeferenced), the horizontal accuracy of the resulting georeferenced index image images was relatively poor, yet deemed adequate for digitizing the approximate upper left corner locations of the individual photos that appeared on each index. The upper left corners for 3,200 photos are shown on the 20 digital index maps.
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Digitize Photo Index Upper Left Corner Point Features - Using ESRI ArcGIS software, point features were manually digitized at the location of the upper left corner of each photo in each of 20 digital photo index images. The photo's flight line and photo number appeared in the upper left corner of each photo, making it possible to digitize the corner location and simultaneously encode the corresponding attribute information identifying the photo. Approximately 3,2000 point features were digitized. Point features were digitized on the screen at display scales greater than 1:24,000. Feature location and attribute accuracy was visually checked and inspected by symbolizing and labeling features according to their flight line, photo number and index sheet number attribute values on the computer screen.
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Convert Photo Index Upper Left Corner Point Features to Center Point Features - Using ESRI ArcGIS software, the Upper Left corner point feature class was copied to a feature class named Photo_Index_1965_Center. With the digital index map images displayed in the background as a reference, all point features in the Photo_Index_1965_Center feature class were selected and moved (shifted) to their center point locations by the compiler focusing attention on the repositioning of just one of the points. All points were moved relative to the repositioning of the that one chosen point. The used as the basis for repositioning all points was chosen because it was for a photo tile whose center was clearly visible on the index. Note most photos overlap each other on the index maps, making it difficult to individually ascertain their centers. Photo tiles usually only seen in their entirety along one edge or in the corner of an index map. In sum, the center point feature class was created by moving all upper left corner center point features approximately 5,000 feet to the right (east) and 5,800 feet down (south). Spot check comparisons of the resulting center point locations to the centers of the corresponding photo prints suggests they are positioned within 500 to 1,500 feet of their true location.
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Internal feature number.
ESRI
Feature geometry.
ESRI
Photo Number
State of Connecticut, Department of Environmental Protection
Flight Line Number
State of Connecticut, Department of Environmental Protection
Index Map Sheet Number
State of Connecticut, Department of Environmental Protection
The PHOT0_NO, FLIGHTLINE, and SHEET_NO attributes uniquely identify the photo, the plane flight path, and the index map sheet number that the upper left corner of the photo apears on. Note a series of 19 photos exists between flight lines 38 and 39. The compiler attributed these photos wit FLIGHTLINE values encode as 0 (zero) because a flight line number for these photos was not depicted on the index map sheet. It appears these photos were taken to fill in a section not covered by flight lines 38 and 89.
No other description of the entity types, attributes, and attribute values for the data set are known to exist.
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Although these data have been used by the State of Connecticut no warranty, expressed or implied, is made by the State of Connecticut as to the accuracy of the data and or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the State of Connecticut in the use of these data or related materials. The user assumes the entire risk related to the use of these data. Once the data is distributed to the user, modifications made to the data by the user should be noted in the metadata.
To order printed copies of individual 1965 aerial photos, contact Keystone Aerial Surveys, Inc. PO Box 21059, Philadelphia, Pennsylvania, 19114-0559, telephone 215-677-3119.
The data distributor does not provide custom GIS analysis or mapping services. Data is available in a standard format and may be converted to other formats, projections, coordinate systems, or selected for specific geographic regions by the party receiving the data.
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