Simulation of spaceborne microwave radiometer measurements of snow cover from in-situ data and emission models

In this study, spaceborne brightness temperature measurements of snow-covered sparse forest are simulated from a daily data set collected at Sodankylä, Finland during winter 2006-2007. The data set consists of measurement data of soil, snow and air. The atmospheric effects are simulated with two different methods: from measurements near the ground and from balloon-borne radio sounding profiles. The simulation results are compared to AMSR-E observations. The results show, that on low frequencies (below 20 GHz) the differences between the two methods are minimal, but the higher the frequency, the larger the differences and simulation errors are. The simulations with ground-based measurement data have lower RMS error than the ones with sounding profiles. As a conclusion, on low microwave frequencies both methods work equally well, but on higher frequencies ground-based observations and models give more accurate results than sounding profiles.