A hybrid lidar-radar system for detecting the presence of objects, such as cancerous
tumors, within tissues by detecting reflected signals from the tissue and discriminating
the information related to the cancerous tumor from the undesirable backscattering
of light created by the tissue itself. The hybrid lidar-radar system utilizes continuous
wave light that is preferably modulated at frequencies up to 60 GHz. The present
invention filters the return signals from the tissue at a subcarrier modulation
frequency so as to reject erroneous information contained in scattered lights,
while at the same time retaining the coherent, unscattered and modulated light
information so as to provide for an accuracy detection of tumors within tissues.