In addition to open source satellite data, some of which are listed in the article Publicly Available Earth Remote Sensing Data: How to Obtain and Use , there are many derived products such as relief. Moreover, you can find open reliefs of different spatial resolution, as well as many commercial ones, and the task arises to choose the best product available.
Today we will consider the openly accessible relief with a spatial resolution of 30 m and 1 m and will be comparable to the commercial resolution of 1 m.To compare and assess relief of different scales, we use the methods of analyzing the spatial spectrum, which are repeatedly described in my previous articles, for example, Spatial spectra and fractality of relief, forces gravity and images Due to the fractal nature of the relief, its spectrum in double logarithmic coordinates must coincide with the line, and the measure of this coincidence is the quality of the relief, and the resolution, starting from which the components of the spectrum obey the law of fractality, is its real resolution. As will be shown in the highly detailed open relief, the chosen estimation method is correct.
Relief USGD NED DEM 1m and ALOS DEM 30m with Google Satellite
Introduction
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