 The study develops a more robust discriminant function algorithm, DFA, for detecting soil freeze-thor, foot, state using temperature and emissivity information from advanced microwave scanning radiometer enhanced, AMS-IE, satellite observations, which is validated with institute soil temperature records and achieves an overall discriminant accuracy of 90%. The study also compares the results of the new function to the soil moisture active passive freeze-thor product and finds a reasonable consistency between them. This article was authored by Ping Kai Wang, Jin Jie Zhao, Jin Chengxia, and others.