This article suggests the use of a cross-layer constraint (CLC), originated from the intrinsic relation between time slices
of range-gated imaging Lidar, to facilitate the three-dimension contour reconstruction of the target. By using this
physical-based method, both the effect of range ambiguity in the raw data and the dependence on the empirical image
processing can be reduced, even when the Lidar system is operated on defocused state. Three outdoor scenes are fully
studied to demonstrate the validity of CLC method, by using the data released by the push-broom range-gated imaging
Lidar system newly developed for wide area depth mapping.