Remote Sensing of Soil Moisture

Table 3

Sensitivity of radar channel to 0–6 cm layer gravimetric soil moisture evaluated over corn and soy fields. L band vertically copolarized channel is seen to be most sensitive to soil moisture and the sensitivity is seen to be higher for soy fields as compared to corn fields. A number of negative sensitivity values during the dry period DOY 176–178 indicate that the contribution of soil moisture to the radar backscatter was masked out by vegetation and surface roughness effects [41].

Period	lhh	lvv	lvh	shh	svv	svh
Corn
176–178	0.237	0.115	−0.214	0.138	−0.173	0.051
187-188	0.222	0.302	0.199	0.114	0.120	0.122
188-189	0.309	0.421	0.374	0.078	0.103	0.113
Soy
176–178	0.019	−0.114	0.329	−0.001	−0.521	−0.086
187-188	0.454	0.639	0.360	0.387	0.380	0.324
188-189	0.625	0.504	0.666	0.335	0.105	0.219

Active channels (sensitivity = (Δ𝜎/Δ𝑚_𝑔) * 0.01).