Thoughts - PGS Stutter and Sharp Turn Vectors
PGS EarthSat Stutter Vectors
These stutter vectors occur throughout the world on the PGS data base. They are obviously a hiccup in the automated vector drawing tool used by EarthSat. They show up as you zoom in. Are they a problem? If NGS paid per vector they definitely were overcharged. If the user does not zoom to the 1:7,280 scale, they are barely visible. However, if you expect PGS to track the visible shoreline, they are a problem. They are a problem that occurs throughout the PGS data base. These stutter vectors should be cleaned up.
PGS EarthSat Sharp Turn Vectors
These sharp turn vectors are angles that do not track the coastline. Again they are found throughout the PGS data base, so it happened during the vector creation phase. You can follow a curving shoreline that periodically has these sharp turns interspersed throughout. Again, they are barely discernable at 1:62,500 and above. However, they are part of the PGS data base and they do not track the shoreline accurately. They should be corrected as well.
EVS will correct all of these issues. EVS, properly administered, identifies the visible shoreline, and then tracks it with greater precision than PGS. PGS took a great deal of time, effort and money. A team of volunteers needs to adjust PGS to EVS precision. A one-time effort by volunteers using rigorous guidelines and then having their work QC'd to ensure an EVS quality map file.
