The following shot types are used in Survey / Map:
FS - foreshot is a shot on the traverse centerline from current instrument position to the next instrument position.
BS - backshot is a shot on the traverse centerline from current instrument position to previous instrument position. Matching FS and BS shots are averaged.
IFS - intermediate field shot is a shot on the centerline which will not be occupied. The bearing of the IFS shot is assumed to be the same as the next FS.
RS - radial shot is a shot off the traverse at any orientation.
SSL (SSR) - Side Slope Left (Right) are shots assumed to be on a perpendicular cross section to the main centerline.
SSL-FS(SSR-FS) - is a foreshot on the perpendicular cross section. This point is occupied.
SSL-IFS(SSR-IFS) - is an intermediate field shot on the perpendicular cross section. This point is not occupied.
