These files contain 2004 digital orthoimagery of Rensselaer County, New York. Image pixel size is 30 cm. GSD. Image type is natural color. Image horizontal accuracy is +/-4 ft. at the 95% confidence level. Each file contains an image covering 750 meters by 750 meters on the ground.
This digital orthoimagery can serve a variety of purposes, from general planning to field reference for spatial analysis to a tool for revision of vector maps. It can also serve as a reference layer for GIS.
Digital elevation models used for orthorectification were compiled from several sources, all of which were compiled photogrammetrically.
ground condition
30 South Pearl Street
The dataset contains raster images or digital ortho images so the logical consistency report is not applicable. The file naming convention was supplied by New York state and is based on the co-ordinate pair of the lower left corner of the ortho tile. When the ortho tiles were created the file names were restricted to a numeric value representing the lower left corner of the ortho tile. 10470162 which represented a tile with the lower left corner of 1047000, 162000. These tiles were then all renamed using a batch script so that they reflected the N.Y. state standard e_10470162_12_07200_col_2004.tif Consistency of file naming was ensured by the batch process.
The project consisted of 730 final tiles
+/-4 ft. at the 95% confidence level (NSSDA)
Not applicable.
The aerial film was acquired in 2004. The imagery was scanned at 14 microns using a Z/I Imaging Photoscan TD-1 scanner. The Ground control used to support the ortho mapping was collected by identifying strategic points on the aerial photography then determining the coordinates by ground survey techniques. The Aerial Triangulation was performed using softcopy workstations and Intergraph's ISDM software. Bundle adjustment was performed using PAT-B and Digital Elevation Models were created using standard photogrammetric collection techniques on Intergraph's SSK soft copy workstation. During the bridging process,both the DEM and the bridge deck were captured as well as the ground features surrounding the bridge. A "DTM apron" was delineated at each side of the elevated bridge and the resulting smearing is located and accumulated in the solid black apron area. The images were then ortho rectified using Intergraph's Base Rectifier software. Color balancing was performed using both Intergraph's IRASC package and Orthovista. Seamless mosaicing was performed using Triathlon's AIM software and the seamless mosaic was clipped into tiles using Triathlon's Clipmos software. Images were then inspected using Intergraph's IRASC and Adobe PhotoShop software. Final files were then compressed using MrSID. Final deliverables in tiff format with tfw files were placed on DVD while the MrSID files were placed on CD. Final quality control for horizontal accuracy and image quality was performed by New York State.
30 South Pearl Street