The Connecticut 2005 Coastal Photography Point Index is a point feature class that defines the centroid of the approximate geographic area covered by each Connecticut 2005 Coastal Photography image. The 2005 Coastal Photography data for Connecticut is comprised of 1105 non-georeferenced 1:12,000 scale vertical color infrared aerial images and these data include a point feature for each image. The extent of all the points comprise a project area described by: * all land areas within one-thousand (1000) feet of Mean High Water (MHW) and within one-thousand (1000) feet of state-regulated tidal wetlands; * an area of at least two-thousand (2000) feet waterward of the immediate shoreline of Long Island Sound; * all offshore islands within the territorial borders of the State of Connecticut including Goose Island and Falkner Island (offshore of Branford); Calf Islands and Great Captain Island (offshore of Greenwich); Norwalk Islands (offshore of Norwalk); Thimble Islands (offshore of Branford); Sandy Point (offshore of Stonington); and all islands in the Connecticut part of Fishers Island Sound; and * the main stem of the Connecticut River up to the Massachusetts State line. The Connecticut 2005 Coastal Photography Point Index is organized in a non-regular pattern that reflects the orientation of the flight lines needed to accurately and efficiently photograph the project area. The points represent the centroid of photos. These photos have an approximate endlap (overlap between tiles in adjacent flightlines) of 15% and an approximate sidelap (overlap between adjacent tiles within a flightline) of 60% in order to achieve well defined stereo pairs. Each point feature is identified by a unique ID_NO and PHOTO_NO value. The ID_NO is a unique, consecutive numbering scheme which matches the filename of the corresponding digital photo image as well as the hardcopy prints and transparencies maintined by the State of Connecticut Department of Environmantal Protection. PHOTO_NO is a unique numbering scheme assigned to the data by the vendor, James W. Sewall, Co. In addition, each point feature also includes basic information on the flight including the year, photography type, tide control, vegetation state, scale, etc.
The Connecticut 2005 Coastal Photography is neither orthorectified nor georeferenced to any real-world coordinate sytem. To maximize the quality of the images and their contents, photography conformed to the following environmental conditions: * photos were only taken during times of no/minimal cloud cover when lighting and weather conditions optimized the color infrared film; * solar altitude was more than thirty (30) degrees; * the ground detail was not obscured by flooding; * the foliage (salt marsh vegetation in particular) was fully developed; * seasonal conditions (summer) favored maximum human use/recreation activities (e.g., boats & temporary docks/structures in water, etc.); * photo times were planned within one (1) hour window before or after a predicted low tide based on National Oceanic & Atmospheric Administration (NOAA) predicted tide tables. (In instances where this window caused conflicts with the general restricted hours, tide coordination times superceded that limitation); and * no photography was flown between the hours 1100 and 1300 Eastern Standard Time (EST) to minimize specular reflection. The photos exist as 1:12,000 vertical color infrared images. Color infrared photography, often called false color photography because it renders the scene in other than the normal colors seen by the human eye, is widely used for interpretation of natural resources. Atmospheric haze does not interfere with the acquisition of the image, therefore is well suited to aerial photography. Because the film is high speed and subject to degrees of degradation in handling before exposure, the aerial photographs can vary in overall tone. This variability can complicate the interpretation of color tones between photographs, but some general guidelines can be given to aid the inexperienced interpreter. * The red tone of color infrared aerial photographs is almost always associated with live vegetation. Very intense reds indicate vegetation which is growing vigorously and is quite dense. Knowledge of the vigor and density of vegetation is important to the interpretation of the red colors on color infrared aerial photography. * As the vigor and density of vegetation decreases, the tones may change to light reds and pinks. If plant density becomes low enough the faint reds may be overcome by the tones of the soils on which the plants are growing. The ground areas in this case will appear in shades of white, blue, or green depending on the kind of soil and its moisture content. As plant vigor decreases, the vegetation will show as lighter shades of red and pink, various shades of greens, and possible tans. Dead vegetation will often be shades of greens or tans. * Bare soils will appear as shades of white, blue, or green in most agricultural regions. In general, the more moist the soil the darker the shade of that particular soil color. Composition of the soil will affect the color tones shown on the photographs. Dry sand will appear white and, with more moisture, may be very light gray or possibly light tan. Clayey soils will generally be darker in color than sands and tend toward tans and bluegreens. Again, wetter clays will be darker shades of the same tones. Soils high in organic matter, like silts and loams will be even darker in color, and usually in shades of blues and greens. Wet organic soils can be very dark blue or green in the aerial photographs. * Man-made features will show in the tones that relate to the materials they are made of. Asphalt roads, for example, will be dark blue or black, gravel or dirt roads will show as lighter colors, depending on the soil materials involved in their composition, and concrete roads will appear light in tone, assuming clean concrete. The buildings and streets of towns can be considered in a similar manner, their color dependent on the material they are made of. * Water will appear as shades of blue, varying from nearly black to very pale blue. Clear, clean water will appear nearly black. As the amount of sediment increases, the color becomes increasingly lighter blue. Very shallow water will often appear as the material present in the bottom of the stream. For example, a very shallow stream with a sandy bottom will appear white due to the high level of reflection of the sand. * Degraded film will result in photographs which have an overall blue or green cast. When that occurs, the interpretation must consider what that overall cast will do to a "normal" rendition of the scene. (Description and guidelines for color infrared photography taken from the United States Geological Survey Aerial Photo FAQ web page, http://edc.usgs.gov/guides/news/aerialfaq.htmlt#A10)
photography date
Point based features representing the center of the 2005 Coastal Connecticut Aerial Survey (Source: State of Connecticut, Department of Environmental Protection)
Entity responsible for maintaining the current data. (Source: State of Connecticut, Department of Environmental Protection)
Internal feature number. (Source: ESRI)
Feature geometry. (Source: ESRI)
Text field indicating the year the photos were taken in. (Source: State of Connecticut, Department of Environmental Protection)
Numeric field providing a unique identifier for each tile that matches the filename of the corresponding digital photo image as well as the hardcopy prints and transparencies maintined by the State of Connecticut Department of Environmantal Protection (Source: State of Connecticut, Department of Environmental Protection)
Text field providing a unique identifier for each tile created by the vendor. (Source: James W.Sewall Co.)
| Range of values | |
|---|---|
| Minimum: | 1 |
| Maximum: | 1105 |
Identifies which roll of film was used for the photo(s.) (Source: State of Connecticut, Department of Environmental Protection)
| Range of values | |
|---|---|
| Minimum: | 1 |
| Maximum: | 7 |
Identifies which flight line was associated with the photo(s.) (Source: State of Connecticut, Department of Environmental Protection)
| Range of values | |
|---|---|
| Minimum: | 1 |
| Maximum: | 47 |
Identifies the specific date a photo was taken. (Source: State of Connecticut, Department of Environmental Protection)
Identifies the time a photo was taken, if applicable. Time values were only recorded for the first and last photos in a flightline. (Source: State of Connecticut, Department of Environmental Protection)
Scale of the photos. (Source: State of Connecticut, Department of Environmental Protection)
Type of film used to capture the photos. (Source: State of Connecticut, Department of Environmental Protection)
Identifies the type of photo by classifying the camera orientation. (Source: State of Connecticut, Department of Environmental Protection)
Indicates if tide control was used an in what manner. (Source: State of Connecticut, Department of Environmental Protection)
Identifies during what state deciduous vegatation was in when the photography (Source: State of Connecticut, Department of Environmental Protection)
DPI (Dots Per Inch) of the digital scans of the original film transparencies. (Source: State of Connecticut, Department of Environmental Protection)
Average Feet Per Pixel: Calculation relating the scale of the photography to the DPI of the scanned imagery to provide a ground measurement, in feet, for each pixel. Defined by [photo scale/image DPI/12] (Source: State of Connecticut, Department of Environmental Protection)
Entity responsible for compiling the original data. (Source: State of Connecticut, Department of Environmental Protection)
Feature geometry. (Source: ESRI)
Information encoded about the point features includes the name of the corresponding photo image (PHOTO_NO), the aerial flight data (FLTLINE_NO, ROLL_NO, PHOTODATE, PHOTOTIME, PHOTOSCALE, etc.) and project data (PHOTO_YR, VEGETATION, TIDE_CNTRL, etc.)
not applicable
James W. Sewall Co. of Old Town, Maine was contracted by the State of Connecticut to perform the 2005 Connecticut Coastal Color Infrared Aerial Photography Project. All imagery and data products were defined under State of Connecticut contract award number 05PSX0128AA.
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These data serve as a point index to the set of 2005 Coastal Photography image tiles for Connecticut.
Used to provide the GPS coordinates of the center poits and ancillary flight capture data.
Used to correlate the identifiers in the JWS_NAME field to the unique numbering scheme used for each photo.
Used to retrieve the unique numbering schema to cross reference against the flight/photo processing logs and the naming convention in the attribute data of the photo center points.
GPS Photo Center Point Creation: Using airborne GPS recievers linked to the cameras and flight management system, center points based on the latitiude & longitude (in decimal degrees) were generated for each photo. These points were then projected into Connecticut State Plane Coordinates, NAD83 in an ESRI shapefile format. Due to areas where reflights took place, in some cases only the photo center of one of the images is presented (although there are cases where both are presnted.) Thus, instead of centers for the 1129 photos taken over the course of the flight, there are only 1105.
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Aerial Photo Center Point QA/QC: The Connecticut 2005 Coastal Photography Point Index layer was cross referenced against the flight/photo processing logs and the project area photo index maps to ensure all photos were represented and to all a field to record the unique sequential naming convention used by the State of Connecticut Department of Environmental Protection. The PHOTO_NO attribute values (representing flight line and exposure number) were compared to flight/photo processing logs and hardcopy index maps of the project area to relate the flight line & exposure numbers with the unique, sequential numbering system found in the logs and on the hardcopy index maps. In most cases there was an exact match, although in areas of relight in the Connecticut River area (Hartford to Rocky Hill) certain photo information from the flight/photo logs did not provide unique sequential numbers. It was determined that duplicate photos were recorded in the logs and that the photo center points did not account for all of the reflight photos, rather a point was captured to hold one of the two. Once this was understood, the data reflected in the numbering scheme from hard copy index maps was transferred to the ID_NO field to ensure unique identifiers and to accurately reflect the paper photo indices. In addition, separate fields were added to record the flight information including the year, photography type, tide control, vegetation state, scale, etc.
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The Connecticut 2005 Coastal Photography Point Index layer retains the feature types and information identified by the State of Connecticut, Department of Environmental Protection and required for the project. All attributes have valid values. Values are within defined domains. The PHOTO_NO attribute values (representing flight line and exposure number) were compared to flight/photo processing logs and hardcopy index maps of the project area to relate the flight line & exposure numbers with the unique, sequential numbering system found in the logs and on the hardcopy index maps. Using this process, the unique sequential numbers were added to a new field, ID_NO. PHOTO_DATE, PHOTO_TIME were not manually entered by captured by flight data systems. FLTLINE was added by to identify photo center points by flight line, and was populated by sorting the PHOTO_NO field, selecting all records with common flight line data, and tranferring the appropriate value to the FLTLINE field via automated calculations.
Accuracy values were derived from the Aerial Flight Inertial Measurement Unit (IMU) processing results.
The completeness of the data reflects the content of the data sources, which include the 2005 Connecticut Coastal Color Infrared Aerial Photos and the 2005 Connecticut Coastal Color Infrared Aerial Photos Index Sheets. The 2005 Connecticut Coastal Color Infrared Aerial Photo Centers layer is complete in the sense that it accurately reflects the content for the project area of the 2005 Coastal Color Infrared Aerial Photos available at the time James W. Sewall Co. created the layer. However, due to reflights to capture portions of the upper Connecticut River (in the Hartford to Rocky Hill areas, certain photos that are in the 2005 Connecticut Coastal Color Infrared Aerial Photo inventory are not presented here. This layer, to the maximum extent possible, reflects the data shown on the 2005 Connecticut Coastal Color Infrared Aerial Photos Index Sheets. This data is not updated.
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 shapefile format. 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, and is not intended for maps printed at scales greater or more detailed than 1:12,000 scale (1 inch = 1,000 feet). 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.
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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.
| 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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