Assessment of Soil Moisture Retrievals over a Mexican Agricultural Area Using Brightness Temperature of RSIR Products.

The need to remotely obtain Soil Moisture (SM) measurements has been a challenge in recent years. Worldwide, this generates a scientific interest on remote sensing field. As a result, there are many techniques to retrieve SM from remote observations of different sensors, for example, mission SMOS can retrieve soil moisture from Brightness Temperature (TB) measurements at coarse spatial resolution. However, these resolutions for agricultural purposes are not suitable, for this reason, we are focused on the assessment of SM retrievals from the improvement of TB products over agricultural fields with similar weather conditions and crop field characteristics. Initially, we obtained TB at 9km and 3km in H and V polarization from NSIDC over agricultural fields in Mexico. Later, we computed retrieval model to retrieve SM. Finally, we obtained RMSD equal to 0.1 and low Pearson correlation coefficients, such as 0.068 in 2018 at 3 km (the lowest value) and 0.5711 in 2019 at 9 km (the highest value). In addition, BIAS and ubRMSD are similar to each other. Nevertheless, they showed poor performance in the Huamantla crop fields. But this does not limit the application to other regions of Latin America.