Grid DEM (digital elevation model) data-based equidistant weight interpolation encryption method

The invention relates to a grid DEM (digital elevation model) data-based equidistant weight interpolation encryption method and belongs to the geographic information application technical field. According to the grid DEM data-based equidistant weight interpolation encryption method, initial DEM data are selected according to actual application; after calculation, the grid DEM data are converted into the elevation information of each grid point; based on a characteristic that surface elevations are continuous, an interpolation algorithm is adopted to perform equidistant interpolation on most adjacent points selected from points in the x and y direction of a point matrix; the weight of influence on interpolated points caused by the elevations of the two known points is determined according to distances from the interpolated points and the two known most adjacent points in the initial point matrix, so that a point matrix with higher point density can be obtained; and the elevation information of a corresponding