I have a question about the accuracy affected by the choice of check point
In my survey, I chose 5 check point out of total 15 GCP.
actually, when I chose them randomly (half is located in the side, the others in the middle of area), I got around 0.02-0.03 accuracy. After that, I heard that check point could be better when ones in the middle of area are selected because of interpolation show better accuracy than extrapolation.
Therefore, I tried to conduct two other process: one is the selection points only in the middle of area, the other is the selection points in the corner or side of area.
Surprisingly, the first process (0.032-0.035) is better than the second (0.031-0.040), but the original method I did with randomly chosen points shows the best accuracy.
I can’t explain why the results is like this…
could you tell me the reason, or is any principle to choose control point for optimal accuracy?