Soil Moisture Mapping with a Passive Radiometer and a Uav.

Skaha Remote Sensing has developed a dual-polarized, passive microwave radiometer that can be mounted on a UAV and has conducted several pilot projects in Canada to assess the feasibly of using this instrument to monitor soil moisture of crop fields. The UAV-mounted sensor operates at 1.4 GHz and uses an internal calibration source to derive absolute microwave brightness temperatures of the ground. The technical details of the sensor will be discussed and results from the pilot studies will be presented, which include soil moisture maps of irrigated and unirrigated fields as well as comparisons with ground truth data obtained with traditional soil moisture probes (Campbell Scientific CS655-L). Additionally, preliminary results obtained with a P-band (450 MHz) radiometer over irrigated fields will be presented along with ideas of how these data can be used as decision tools in agriculture.