Comparison: SWBD, WVS and EVS
SWBD - SRTM Water Body Data
WVS - World Vector Shoreline (1:250,000)
EVS - Enhanced Vector Shoreline (Below 1:125,000)
Now that we have the three data sets identified, I will show you a map that offers an excellent display of the three aforementioned vector files.
Comparison of SWBD, WVS and EVS
The red lines are WVS map files. I believe they are out of whack due to different datums. WVS uses Nad-83 while SWBD uses WGS-84. In addition WVS was extracted from TPC (Tactical Pilotage Charts) 1:250,000 DMA produced charts. Unfortunately, these charts are based on some fairly old data (40's through the 70's).
The dark brown lines are SWBD map files. They match the Landsat base image closely. I will display their position in a zoomed image.
Comparison of SWBD, WVS and EVS - Detail
Although SWBD does track the coastline, the track is still coarse compared to the EVS map. SWBD does not attempt to depict the various motus that makeup this atoll. It tracks the shorelines.
Although SWBD is interesting and offers some highly accurate map files, they do not resolve at the same accuracy as the EVS files.
