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Connecticut 1965 Aerial Photo Upper Left Corner Index

Frequently-asked questions:


What does this data set describe?

Title:
Connecticut 1965 Aerial Photo Upper Left Corner Index

Abstract:
Connecticut 1965 Aerial Photo Upper Left Corner Index is a photo index for the 1965 Aerial Survey of Connecticut with approximate locations for the upper left (northwest) corner location of 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.

Supplemental information:
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.

  1. How should this data set be cited?

    State of Connecticut, Department of Environmental Protection (data compiler, editor and publisher), 20040811, Connecticut 1965 Aerial Photo Upper Left Corner Index: State of Connecticut, Department of Environmental Protection, Hartford, Connecticut, USA.

    Online links:
    Other citation details:
    The State of Connecticut, Department of Environmental Protection is the collector of the data (compiler), the creator and maintainer of the data layer (editor), and producer (publisher) of this information for use.

  2. What geographic area does the data set cover?

    Bounding coordinates:
    West: -73.764131
    East: -71.727691
    North: 42.078297
    South: 41.015106

  3. What does it look like?

    http://www.cteco.uconn.edu/metadata/dep/browsegraphic/photoindex1965upperleftfullview.gif (GIF)
    Full view of 1965 Photo Upper Left Corner Index. These are approximate locations for the upper left (northwest) corner location of each 1965 aerial photograph.

    http://www.cteco.uconn.edu/metadata/dep/browsegraphic/photoindex1965upperleftdetailview.gif (GIF)
    Detail view of 1965 Photo Upper Left Corner Index labeled with the Flight Line and Photo Number values. These are approximate locations for the upper left (northwest) corner location of each 1965 aerial photograph.

  4. Does the data set describe conditions during a particular time period?

    Calendar date: 1965
    Currentness reference:
    Date of photography

  5. What is the general form of this data set?

    Geospatial data presentation form: vector digital data

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      Indirect spatial reference:
      The combination (concatination) of FLIGHTLINE and PHOTO_NO attribute values (e.g. 1 and 292) uniquely identifies a point feature representing the upper left (northwest) corner location of the photograph.

      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • Entity point (3198)

    2. What coordinate system is used to represent geographic features?

      The map projection used is Lambert Conformal Conic.

      Projection parameters:
      Lambert Conformal Conic
      Standard parallel: 41.200000
      Standard parallel: 41.866667
      Longitude of central meridian: -72.750000
      Latitude of projection origin: 40.833333
      False easting: 999999.999996
      False northing: 499999.999998

      Planar coordinates are encoded using coordinate pair.
      Abscissae (x-coordinates) are specified to the nearest 0.000250.
      Ordinates (y-coordinates) are specified to the nearest 0.000250.
      Planar coordinates are specified in survey feet.

      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257222.

      Vertical coordinate system definition:
      Altitude system definition:
      Altitude resolution: 1.000000
      Altitude encoding method: Explicit elevation coordinate included with horizontal coordinates

  7. How does the data set describe geographic features?

    Connecticut 1965 Aerial Photo Upper Left Corner Index
    Upper left hand corner of aerial photo (Source: State of Connecticut, Department of Environmental Protection)

    OBJECTID
    Internal feature number. (Source: ESRI)
                      

    Sequential unique whole numbers that are automatically generated.

    SHAPE
    Feature geometry. (Source: ESRI)
                      

    Coordinates defining the features.

    PHOTO_NO
    Photo Number (Source: State of Connecticut, Department of Environmental Protection)
                      

    Range of values
    Minimum:3
    Maximum:4125

    FLIGHTLINE
    Flight Line Number (Source: State of Connecticut, Department of Environmental Protection)
                      

    Range of values
    Minimum:0
    Maximum:42

    SHEET_NO
    Index Map Sheet Number (Source: State of Connecticut, Department of Environmental Protection)
                      

    Range of values
    Minimum:1
    Maximum:20

    Entity and attribute overview:
    The PHOTO_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.

    Entity and attribute detail citation:
    No other description of the entity types, attributes, and attribute values for the data set are known to exist.
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Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)


  2. Who also contributed to the data set?

  3. To whom should users address questions about the data?

    Howie Sternberg
    State of Connecticut, Department of Environmental Protection
    79 Elm Street
    Hartford, Connecticut 06106-5127
    USA

    860-424-3540 (voice)
    860-424-4058 (FAX)
    dep.gisdata@ct.gov
    Hours of Service: Monday to Friday, 08:30 to 16:30 Eastern Standard Time
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Why was the data set created?

This point feature class is the data source for the Connecticut 1965 Aerial Photo Center Point Index layer. Use the Connecticut 1965 Aerial Photo Center Point Index layer to identify 1965 aerial photos by flight line and photo number on file at the Connecticut State Library, 231 Capitol Avenue, Hartford, Connecticut 06106.

Note the upper left corner index point features are preserved in this layer in the event these data are needed as a starting point to more accurately derive photo center point features in the future.

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How was the data set created?

  1. Where did the data come from?

    Index Maps (source 1 of 3)

    State of Connecticut, Department of Transportation (publisher of index maps), Unknown, Photo Index Maps: State of Connecticut, Department of Environmental Protection, Hartford, Connecticut, USA .

    Type of source media: print
    Source scale denominator: 63,360
    Source contribution:
    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.

    Digital Index Maps (source 2 of 3)

    State of Connecticut, Department of Environmental Protection (publisher of raster digital data), 20040811, Digital Photo Index Maps: State of Connecticut, Department of Environmental Protection, Hartford, Connecticut, USA .

    Online links:
    Type of source media: disc
    Source scale denominator: 63,360
    Source contribution:
    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.

    Photo_Index_Upper_Left (source 3 of 3)

    State of Connecticut, Department of Environmental Protection (data compiler, editor and publisher), 20040811, Connecticut 1965 Aerial Photo Upper Left Corner Index: State of Connecticut, Department of Environmental Protection, Hartford, Connecticut, USA.

    Online links:
    Type of source media: disc
    Source scale denominator: Unknown
    Source contribution:
    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.

  2. What changes have been made?

    Date: 20040811 (change 1 of 2)
    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.

    Person responsible for change:
    Howie Sternberg
    State of Connecticut, Department of Environmental Protection
    79 Elm Street
    Hartford, Connecticut 06106
    USA

    860-424-3540 (voice)

    Data sources used in this process:
    • Index Maps

    Data sources produced in this process:
    • Digital Index Maps

    Date: 20040811 (change 2 of 2)
    Digitize Photo Index Upper Left Corner Point Peatures - 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.

    Person responsible for change:
    Janet Zeh
    State of Connecticut, Department of Environmental Protection
    79 Elm Street
    Hartford, Connecticut 06106
    USA

    860-424-3540 (voice)

    Data sources used in this process:
    • Digital Index Maps

    Data sources produced in this process:
    • Photo_Index_Upper_Left

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How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?

    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.

  2. How accurate are the geographic locations?

    The horizontal positional accuracy of this data is unknown.

  3. How accurate are the heights or depths?

  4. Where are the gaps in the data? What is missing?

    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.

  5. How consistent are the relationships among the observations, including topology?

    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.

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How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access constraints: None. No restrictions or legal prerequisites for accessing the data. The data is in the public domain and may be redistributed.
Use constraints:
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 Upper Left Corner Index layer, compiled and published by CT DEP.

Distributor 1 of 1

  1. Who distributes the data set?

    State of Connecticut, Department of Enviromental Protection
    79 Elm Street
    Hartford, Connecticut 06106-5127
    USA

    860-424-3540 (voice)
    860-424-4058 (FAX)
    dep.gisdata@ct.gov
    Hours of Service: Monday to Friday, 08:30 to 16:30 Eastern Standard Time

  2. What's the catalog number I need to order this data set?

    Connecticut 1965 Aerial Photo Upper Left Corner Index

  3. What legal disclaimers am I supposed to read?

    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.

  4. How can I download or order the data?

    • Availability in digital form:


    • Data format:
      in format Shapefile, Feature Class (version ArcGIS)
      Network links:http://www.ct.gov/deep

    • Cost to order the data: An online copy of the data may be accessed without charge.


    • Cost to order the data: Unknown


    • Special instructions:

      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.

    • How long will it take to get the data?

      Unknown

  5. Is there some other way to get the data?

    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.

  6. What hardware or software do I need in order to use the data set?

    Geographic information sytem (GIS), computer-aided drawing or other mapping software is necessary to display, view and access the information.

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Who wrote the metadata?

Dates:
Last modified: 20111208

Metadata author:
Howie Sternberg
State of Connecticut, Department of Environmental Protection
79 Elm Street
Hartford, Connecticut 06106-5127
USA

860-424-3540 (voice)
860-424-4058 (FAX)
dep.gisdata@ct.gov
Hours of Service: Monday to Friday, 08:30 to 16:30 Eastern Standard Time

Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata(FGDC-STD-001-1998)

Metadata extensions used:
  • http://www.esri.com/metadata/esriprof80.html

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