Detectability and Locatability of Multiple Gross Errors in DEM Matching Algorithm

DEM matching algorithm without control points is the base for detecting deformation method, the deformation existing in DEMs is treated as gross error. The detectability and locatability of multiple gross errors is very critical according to the surveying error and reliability theory. The interactive observations number (ION) derived from gross error judgement matrix is adapted in this paper. The relationship between zero-column vectors in judge matrix and the rank of the coefficient matrix of DEM matching is discussed in theory, and prove none zero-column vectors exist with real date sets. ION Equal to the number of redundant observations. Experimental results show that DEM matching algorithm has the detectability and locatability of multiple gross errors, and the deformation can be correctly detected by robust estimators in prearranged confidence level.