Connecticut 1990 Orthophoto Tile Index

Frequently-asked questions:

• What does this data set describe?
  1. How should this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. Where did the data come from?
  2. What changes have been made?
• How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
  6. Is there some other way to get the data?
  7. What hardware or software do I need in order to use the data set?
• Who wrote the metadata?

Connecticut 1990 Orthophoto Tile Index contains polygon features that dellineate the boundaries used by the USGS in the creation of the 1990 digital ortho quarter quads (DOQQs) for Connecticut. This index grid may be used to determine the name of the 1990 DOQQ file for a particular tile. Aerial photography was acquired during the spring of 1990. It is 1 meter orthorectified imagery, single band (black and white), leaf off. The ground resolution for this imagery is 1 meter per image pixel.

1. How should this data set be cited?
   
   
   State of Connecticut, Department of Environmental Protection (data editor and publisher), 20100701, Connecticut 1990 Orthophoto Tile Index.
   
   
   Online links:

   • http://www.ct.gov/deep

   
   
2. What geographic area does the data set cover?
   
   
   Bounding coordinates:

   West: -73.766497

   East: -71.739325

   North: 42.066812

   South: 40.936017
   
   
3. What does it look like?
   
   
4. Does the data set describe conditions during a particular time period?
   
   
   Calendar date: 20100701
   Currentness reference:

   publication date

   
   
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?
      
      
      This is a Vector data set. It contains the following vector data types (SDTS terminology):

      • G-polygon (414)
      
      
   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 1990 Orthophoto Tile Index

   OBJECTID

   Internal feature number. (Source: ESRI)
                     

   
   

   Sequential unique whole numbers that are automatically generated.

   
   

   SHAPE

   Feature geometry. (Source: ESRI)
                     

   
   

   Coordinates defining the features.

   
   

   QGNO

    (Source: State of Connecticut, Department of Environmental Protection)
                     

   
   

   QUAD_NO

   Quadrangle Number - An ID number designated by the State of Connecticut, Department of Environmental Protection, Natural Resources Center in the 1980's to uniquely identify individual 7.5 minute 1:24,000-scale USGS topographic quadrangle maps. The Quadrangle Number value of each point feature identifies the USGS topographic quadrangle map that the orthophoto center point is located on. (Source: State of Connecticut, Department of Environmental Protection)
                     

   
   

   Numeric value. Quadrangle maps published by the USGS that cover the Connecticut mainland and coastal area are assigned numeric values ranging from 1-116. Two quadrangle areas covering the waters of Connecticut in Long Island Sound are assigned numeric values 1213 and 12

   
   

   QUAD_SEC

   Quadrangle Section - There are 4 sections per 7.5 minute quadrangle, each one corresponding to a 3.75 minute quarter quadrangle area. The Quadrangle Section value of each point feature identifies the (NE, NW, SE, SW) section of the 7.5 minute 1:24,000-scale USGS topographic quadrangle map that the orthophoto center point is located on. (Source: State of Connecticut, Department of Environmental Protection)
                     

   
   

   Value	Definition
   NE	Northeast quarter quandrangle
   NW	Northwest quarter quandrangle
   SE	Southeast quarter quadrangle
   SW	Southwest quarter quandrangle

   
   

   QUADRANGLE

   Quadrangle Name - Name of the 7.5 minute 1:24,000-scale USGS topographic quadrangle map published by the USGS that the orthophoto center point is located on. (Source: State of Connecticut, Department of Environmental Protection)
                     

   
   

   Text valuend 12

   
   

   ORTHOPHOTO_TILE

   Orthophoto tile name - Unique name assigned to each orthophoto tile. (Source: State of Connecticut, Department of Environmental Protection)
                     

   
   

   SHAPE.area

   SHAPE.len

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   
   
   • State of Connecticut, Department of Environmental Protection (data editor and publisher)
   
   
2. Who also contributed to the data set?
   
   
3. To whom should users address questions about the data?
   
   

Use this index grid to determine the name of the Connecticut 1990 DOQQ image file for a particular tile.

1. Where did the data come from?
   
   
2. What changes have been made?
   
   

1. How well have the observations been checked?
   
   
2. How accurate are the geographic locations?
   
   
3. How accurate are the heights or depths?
   
   
4. Where are the gaps in the data? What is missing?
   
   
5. How consistent are the relationships among the observations, including topology?
   
   

No restrictions or legal prerequisites for using the data. Although this data set  has been used by the State of Connecticut, Department of Environmental Protection, no warranty, expressed or implied, is made by the State of Connecticut, Department of Environmental Protection 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, Department of Environmental Protection 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. 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.

Who distributes the data set?


State of Connecticut, Department of Environmental Protection


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


Connecticut 1990 Orthophoto Tile Index


What legal disclaimers am I supposed to read?


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



Is there some other way to get the data?


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

79 Elm Street