Restoring urbanization process in China in the 1990s by using non-radiance calibrated DMSP/OLS nighttime light imagery and statistical data

Since current administrative unit-based urban land area statistical data in China lack enough spatial information, the urbanization process research at large scale cannot be effectively supported. Based on the current administrative unit-based urban land area statistical data in China, a new approach to quickly and cheaply derive urban land information from the non- radiance-calibrated Defense Meteorological Satellite Program/ Operational Linescan System (DMSP/OLS) nighttime light imagery is presented in this paper. With the new approach, the urban pattern information in China in 1992, 1996 and 1998 was derived with the urbanization processes in China in the 1990s restored by using the non-radiance-calibrated DMSP/OLS nighttime imagery. The accuracy assessment based on the statistical data showed that the relative error between the derived total urban land area and the statistical data at national scale was less than 2% in 1992, and less than 1% in 1996 and 1998, and the maximum relative error at province scale do not exceed 10% with most of the provinces less than 3%. In addition, the urban patterns derived from the high-resolution Landsat TM imagery were compared with those from the DMSP/ OILS data. The results showed that the urban pattern characteristics derived from DMSP/OLS were basically coincident with those from TM imagery with the total accuracy of about 80%. Thus it can be seen that our restored urbanization process in China in the 1990s by using the non-radiance DMSP/OLS nighttime imagery can be accepted and can represent the actual urban development in China at that time on the whole.