Compute height differences and misclosure around a closed leveling loop.
Σh = Σ(后视 − 前视)。
| Item | Formula / Note | Source / Standard |
|---|---|---|
| Theoretical condition of a closed loop | For a closed levelling loop the sum of height differences is theoretically zero | GB 50026-2020, Code for engineering surveying |
| Misclosure | fh = sum h, the difference between observed and theoretical sums | GB 50026-2020, Code for engineering surveying |
| Tolerance | Limits are set by route length or station count, e.g. ±40·sqrt(L) mm or ±12·sqrt(n) mm | GB 50026-2020, Code for engineering surveying |
| Distribution of misclosure | Corrections are proportional to station count or distance and opposite in sign | GB 50026-2020, Code for engineering surveying |