For the 'eastern' (upland) portion of the project area 306 photos where taken at a photo scale of 1" = 2500', covering an area of approximately 825 sq. miles.
Township tiles created from the 1" = 2500 foot photography are:
Townships 19 Ranges 09-12, Townships 20 Ranges 09-12, Townships 21 Ranges 09-12 Townships 22 Ranges 10-11, Townships 23 Ranges 10-12, Townships 24 Ranges 10-14 Townships 25 Ranges 10-13, Townships 26 Ranges 10-13
All other township tiles were created from the 1" = 1700' photography.
The three half-townships in eastern King County are incorporated into their adjacent full townships, T24R11, T24R12, T24R13, per the tiling scheme.
For the 1" = 1700' source photos: Maximum error, in areas of strong relief or over elevated features (i.e, overpasses), may be as great as 15 feet. Generally, error is expected to be less than this, in the range of 6-10 feet.
For the 1" = 2500" source photos: Maximum error, in areas of strong relief or over elevated features (i.e, overpasses), may be as great as 20 feet. Generally, error is expected to be less than this, in the range of 10-15 feet.
The film negatives were scanned at 11.5 microns by 3di, Easton, MD resulting in a pre-orthophoto rectified nominal pixel size of 0.77 feet for the low-level and 1.13 feet for the high-level. The digital images were output in Tiff-tiled format with separate planar configuration, with pyramid layers. The scanned images were delivered to King County for quality assessment on portable harddrives.
The terrain information was not edited.
The ortho/mosaic seamline autogenerated by the software were not reviewed or edited. Bridges and overpasses/interchanges were not modeled during the orthorectification process. They are rectified to the ground per the LiDAR terrain model, as are all elevated/non-ground features.
The orthophotos were not given a comprehensive quality evaluation.