This article describes the author's method of using data from the Global Human Settlement Layer (GHSL) project in the study of the spatial development of metropolitan areas. The methodology uses raster arithmetic to determine changes in development over time. The advantages and disadvantages of the technique are shown in comparison with Earth remote sensing (ERS) data. The advantages of the methodology are the simplicity of obtaining initial data, ignoring administrative boundaries and features of statistical accounting, applicability to any agglomeration of the world. Disadvantages are low spatial resolution, discrete time series with large time gaps (10–15 years), and lack of development typology. As an example, changes in the development of the St. Petersburg metropolitan area in 2000–2015 are considered.