Soil analysis with georadar

Using SAR and GPR sensors, we can estimate the soil moisture below the Earth's surface. Figure 1 shows an optical and SAR image and a radargram captured by GPR. By fusing the data, we were able to estimate the soil moisture below the surface.

Figure 1. Fusion of SAR and GPR data.

GPR data can be acquired using a ground penetrating radar that can operate at different frequencies: 50MHz, 250Mhz and 500 MHz. The two ground penetrating radars are shown in Figure 2.

Figure 2. 50MHz antenna and GPR with 250MHz antenna
Figure 3. ProEx GPR with 50MHz antenna

We conducted an experiment to estimate the moisture content between boreholes spaced 100 m apart, as shown in Figure 4. For this purpose, we built our own ground penetrating radar based on a Marx generator and used a neural network to estimate the soil moisture content. The time courses of the signals obtained from the ground penetrating radar, which we used to estimate the soil moisture content between the boreholes, are shown in Figure 5.

Figure 4. Illustration of the layout of wells and antennas

Figure 5. Display of time responses of GPR