Photonics-based bi-band Radar for Sub-mm Displacement Measure

Radars based on Stepped-Frequency Continuous- Wave technique with differential interferometry are used for monitoring landslides and other ground failures, providing precise deformation maps of large areas. This technique is limited to the use of coherent sinusoids in a single and fixed RF band Here a photonics-based radar is exploited to perform coherent multi-band differential phase estimation for enhanced displacement measures. Tunable operative RF carriers adapt the system to the environment and to the observation range. The system measured the differential phase over a synthetic band up to 7.4GHz. The experimental results demonstrate a precision < 200m without using correction algorithms