Dictionary:Fig P-3

ADVERTISEMENT
From SEG Wiki
Jump to: navigation, search
Segp3.jpg

FIG. P-3. Plane-table methods. (a) Plane-table traversing. The plane table is set at A and oriented north, the rod at B is sighted with alidade and the line ab is drawn along the alidade edge, the line length depending on the stadia reading. The table is then set up at B, oriented by back-sighting on A, then the alidade is sighted on C and bc is drawn, and so on until the loop is closed at E by sighting on A. (b) Plane-table intersection method. The plane table is set at A and oriented north, the rod at B is sighted with the alidade and ab is drawn depending on the stadia reading. Rod readings at points C, D, E, F, and G are sighted on and their directions plotted. The same points are then sighted on with the plane table set up at B. (c) Plane-table resection. The plane table is set at an unknown location H and the table is sighted on known points A, B, and D. Point H is determined by the line intersections.