Connecticut 2004 Orthophoto Tile Index by Town is a polygon feature class that identifies the location of each Connecticut 2004 orthophoto image tile relative to Connecticut towns. These data are the result of a spatial combination (union) of the Connecticut 2004 orthophoto index with Connecticut town areas. There is one polygon feature for each orthophoto-town combination, with a total of 5,654 orthophoto-town polygon features in the entire feature class. These data include information for all orthophotos, including those located in Connecticut as well as a small number of orthophotos located entirely out of state along the Connecticut state boundary. Each polygon feature record identifies the orthophoto by orthophoto tile name and Connecticut town by official town number and name.
Date of photography
Orthophoto-town footprint. One polygon feature per orthophoto-town combination. (Source: State of Connecticut, Department of Environmental Protection)
Internal feature number. (Source: ESRI)
Feature geometry. (Source: ESRI)
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)
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 quandrangle |
| SW | Southwest quarter quandrangle |
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: US Geological Survey)
Orthophoto tile name - Unique name assigned to each orthophoto tile, which is the basis for individual image files names such as 0400731161_2.tif and 0400731161_2.sid for data in TIF and SID format, respectively. The first 9 digits (e.g. 040073116) identify the USGS 7.5 minute quadrangle map the orthophoto is located on. These first 9 digits are a concatenation of latitude, longitude, and quadrangle numbers. Digits 1 to 3 and 4 to 6 (e.g. 040073) correspond to latitude and longitude values for the quadrangle. Digits 7 to 9 (e.g. 116) represent the quadrangle number. Appended to the first 9 digits is a tenth digit, ranging from 1 to 4, that identifies the 3.75-minute quarter quadrangle area the orthophoto is located on. Appended these first 10 digits is a second sequence number, ranging from 1 to 9 (_1, _2, _3… _9), that identifies the tile section for the orthophoto image (e.g. 0400731161_2). There are 9 possible tile sections per 3.75-minute quarter quadrangle area. (Source: State of Connecticut, Department of Transportation)
State Code (Source: State of Connecticut, Department of Environmental Protection)
| Value | Definition |
|---|---|
| CT | State of Connecticut |
| MA | Commonwealth of Massachusetts |
| NY | State of New York |
| RI | State of Rhode Island |
Town Number - ID number for the Connecticut Town (municipality), based on the Town Codes issued by the State of Connecticut, Office of the State Controller, which range from 1 to 169. (Source: State of Connecticut, Department of Transportation)
Town Name - Text values that correspond to numeric TOWN_NO attribute values. TOWN is the English language equivalent of (decodes) the TOWN_NO field. (Source: State of Connecticut, Department of Transportation)
Town Name - Text values that corresponds to numeric TOWN_NO attribute values. TOWN_NAME is the English language equivalent of (decodes) the TOWN_NO field. Also includes names of Towns for polgygon features from Massachusetts, New York, Rhode Island where TOWN_NO = 0 and LAND_CLASS = "Land". (Source: State of Connecticut, Department of Environmental Protection)
Land Class - Distinguishes land from water. This dataset includes a large water polygon feature that may impact polygon drawing performance. To improve drawing performance, exclude all water features by using the following expression in a layer definition query: LAND_CLASS = "Land" (Source: State of Connecticut, Department of Environmental Protection)
| Value | Definition |
|---|---|
| Land | Land Feature - Mainland or island |
| Water | Water Feature - Marine and selected large fresh waterbody |
Information encoded about each orthophoto-town polygon feature includes the name of the corresponding orthophoto image (ORTHOPHOTO_TILE) and identification of the quadrangle number (QUAD_NO), quadrangle name (QUADRANGLE), quadrangle section (QUAD_SEC), town number (TOWN_NO), and town name (TOWN) the orthophoto is located on.
Aero-Metric, Inc. of Sheboygan Wisconsin was contracted by the State of Connecticut to provide the 2004 Statewide Aerial Survey of Connecticut. Contract deliverables include digital orthohotos, two sets of non-rectified prints for stereoscopic viewing, photo indexes, and LIDAR data. The scale of the accuracy of imagery, data and products meets horizontal National Map Accuracy Standards (NMAS) for 200-scale mapping. Photography is black and white and flown under clear sky conditions when deciduous trees and shrubs are in leafless condition ("leaves off") and the ground is free from ice, snow, cloud shaddows, and floodwaters. The Spring of 2004 was particulary wet, making it extremely difficult to arrive at conditions ideal for conducting a statewide aerial survey. Consequently, portions from 2000, 2005 and 2006 aerial surveys were used for orthophotographic production where there was unacceptable Spring 2004 orthophotography. All 2004 Statewide Aerial Survey imagery and data products defined under State of Connecticut contract award number RFP-990-A-14-0518-C (dated Feb 22, 2000), including contract award supplement #1 (dated Feb 28, 2002), contract award supplement #2 (dated Nov 4, 2004), contract award supplement #3 (dated Nov 26, 2004) and contract award supplement #4 (dated May 13, 2005).79 Elm Street
These data serve as a town index to the set of 2004 orthophoto image tiles for Connecticut. Use it to determine the names of orthophoto image files that cover one or more town. Includes all Connecticut 2004 orthophoto tiles, including the few that are completely located outside the State of Connecticut along the state boundary. Polygon features representing portions of tiles located outside of Connecticut are encoded with Town Number values of 0 (zero).
These data serve as a polygon index to the set of 2004 orthophoto image tiles for Connecticut.
Northeast_Master_Poly is a 1:24,000-scale, polygon and line feature-based layer that includes state, county, town (municipal), and some village boundary features for the States of Connecticut, Massachusetts, Maine, New Hampshire, New Jersey, New York, Rhode Island, and Vermont. Line features include state, county, town (municipal), and village boundaries (primarily for New York). Polygon features are intended to depict the geographic areas for individual towns (municipalities) so that they can be aggregated up and combined to form county and state polygon features in derived data sets. Data is in ArcInfo coverage format in the Connecticut State Plane Coordinate System of 1983 (NAD 83). Map units are in feet. This information does not depict official state, county and town boundaries established by the respective state and municipal governments.
These data serve as town index to the set of 2004 orthophoto image tiles for Connecticut.
Connecticut 2004 orthophoto index polygon features (source 1) were combined (unioned) with the Northeastern United States Political Boundary Master polygon features (source 2). The resulting polygon feature class was further simplified by first selecting all features in Connecticut (STATE_COD = "CT) and then dissolving (merging) adjacent polygon features with the same state, landclass, orthophoto tile and town designations. This process resulted in the creation of a smaller number of larger polygon features that described the orthophoto-town combination in a polygon feature class named Ortho_2004_Index_By_Town (source 3).
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All attributes have valid values. Values are within defined domains. No rigid attribute accuracy tests were conducted other than visual inspection of the geoprocessing results.
The horizontal positional accuracy of this data is unknown.
The completeness of the data reflects the feature content of the primary data sources, which includes the original photo index for the 2004 orthophotos in CAD format from the State of Connecticut, Department of Transportation and a 1:24,000-scale data layer of Connecticut towns used to determine which towns the orthophoto tiles are located in.
Polygon features conform to the following topological rules. Polygons are single part. Polygons overlap along the edges where orthophoto tiles overlap. The overlap between adjacent photos is approximately 350 to 450 feet. Establishment of logical consistency was performed by the State of Connecticut, Department of Environmental Protection using ESRI ArcGIS software to derive these polygon features from a union of two polygon data sources. No automated procedures or tests were performed to guarantee desired topology other than visual inspection.
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, Departments of Environmental Protection and Transportation as the source for this information. For example, include the following data source description when printing this layer on a map: Photo Index - From the Connecticut 2004 Orthophoto Tile Index by Town layer, published by CT DEP and CT DOT.
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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.
| Data format: | in format Shapefile, Feature Class (version ArcGIS) |
|---|---|
| Network links: | http://www.ct.gov/deep |
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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