Domain adaptation for semantic segmentation has recently been actively\nstudied to increase the generalization capabilities of deep learning models.\nThe vast majority of the domain adaptation methods tackle single-source case,\nwhere the model trained on a single source domain is adapted to a target\ndomain. However, these methods have limited practical real world applications,\nsince usually one has multiple source domains with different data\ndistributions. In this work, we deal with the multi-source domain adaptation\nproblem. Our method, namely StandardGAN, standardizes each source and target\ndomains so that all the data have similar data distributions. We then use the\nstandardized source domains to train a classifier and segment the standardized\ntarget domain. We conduct extensive experiments on two remote sensing data\nsets, in which the first one consists of multiple cities from a single country,\nand the other one contains multiple cities from different countries. Our\nexperimental results show that the standardized data generated by StandardGAN\nallow the classifiers to generate significantly better segmentation.\n