Correction of False Topographic Perception Phenomenon Based on Topographic Correction in Satellite Imagery

Most sun-synchronous satellites acquire images when the illumination source is located in the southeast direction, which is contrary to human visual habits. Therefore, when observing such images, the false topographic perception phenomenon (FTPP) occurs, particularly in large-relief regions. FTPP should be corrected because it may induce misunderstandings of terrain features, thus affecting related decision making. Unlike most existing algorithms, an automatic algorithm focusing on altering the illumination direction is proposed on the basis of topographic correction. The purpose of the algorithm is to alter the illumination direction from SE to northwest. The original and FTPP-corrected images can be quantitatively connected by establishing the relationship between these two images after topographic correction by using the C model such that the formula for calculating the DN (Digital Number) value of the FTPP-corrected image can be derived. An online survey of 323 volunteers using two sets of test data demonstrates that the success rate of the topographic-correction-based approach is as high as 85%. In comparative trials, the proposed approach displays a relatively strong ability to preserve the spatial details and the spectral characteristics of the original image.