Coherent laser radar with dual-frequency Doppler estimation and interferometric range detection

The concept of a coherent interferometric dual frequency laser radar, that measures both the target range and velocity, is presented and experimentally demonstrated. The innovative architecture combines the dual frequency lidar concept, allowing a precise and robust Doppler estimation, with the interferometric phase measure technique for the detection of the range with high accuracy. Moreover, the coherent detection approach, exploited for both the range and velocity measurements, allows to enhance the signal to noise ratio reaching excellent performances also with low level of received power. The laboratory characterization in terms of resolution and sensitivity, as well as the indoor demonstration with real targets proves the effectiveness of the proposed architecture.