Comparison of the Performance of MODIS Sensors of Terra and Aqua Satellites in Monitoring the Trend of Snow Cover Changes in Tehran Province Using Time Series of Remotely Sensed Data

The study of snow cover changes, as one of the sources of water supply is very important. The purpose of this study is to investigate the trend of snow cover changes in Tehran province using MODIS sensor images of Terra satellite and Aqua satellite (since 2003) until the end of 2018 and compare the performance of MODIS sensor in these two satellites. The trend of snow cover satellite images changes was determined by ETM analyzer of TerrSET software, their significance was determined by non-parametric methods of Mann-Kendall significance test. Then, the satellite images were validated by analyzing the data trend of synoptic stations in Tehran province using regression methods. Also, the trend of snow cover changes obtained from Terra satellite was compared with the trend of snow cover changes obtained from Aqua satellite by Kappa index. And the time series of these two satellites were compared by the correlation coefficient of Linear Modeling analysis. According to the results, changes in total days with monthly, annual and seasonal snow cover (autumn and winter) have a significant decreasing trend in a scattered manner in most parts of Tehran province. Seasonal trend analysis (STA) showed a delay in the start of days with snow cover and its shift from late January to late March. The correlation coefficient of MODIS sensor time series between two satellites in most parts of Tehran province was 99% and showed high similarity. Validation results showed that the trend of snow cover satellite images changes is 85% similar to the trend of synoptic stations snow cover data changes in Tehran province.