Comparison: PGS vs EVS using Pukapuka Atoll CW
PGS vs EVS - Detail (Motu Ko, Pukapuka Atoll CW)
So, I decided to test the PGS vectors (red lines) against Pukapuka Atoll, Cook Islands digitized at EVS quality. There is a cloud issue on one of the motus. Fortunately, the clouds were not a problem with Motu Ko. I tried to digitize by moving vectors to trace the visible shoreline. I moved more vectors then I didn't. At least 70%+ of the vectors had to be moved to track the visible shoreline. The moves were slight, less than a few millimeters which equals 10's of meters on the ground. Some of the vectors traced reefs that were classified as shorelines (northern part of Motu Ko).
The PGS vectors are close, but no cigar. For EVS quality the PGS vectors require a great deal of adjusting. To produce EVS islands, I need to digitize off of the Landsat image. So, I will keep doing what I do best, making EVS shorelines.
Enjoy!
Labels: Cook Islands, EVS, island, Landsat, map, Marplot, PGS
