Measurement of target range and doppler shift by incorporating PDM-enabled FMCW-based photonic radar

Measurement is an essential part of modern science as well as of engineering, commerce, and daily life. As per recent reports of world health organization (WHO), most accidents occur due to human negligence and hence need of a system which can access the surrounding environment and reflect exact measurement of obstacle is a must to enable fully autonomous vehicle (AV). Photonic radars have materialized as promising candidate to realize AVs via distinguishing traffic pattern, navigation, lane detection and self-parking etc. In this work, we have developed coherent detection-based linear frequency modulated continuous wave (LFMCW) photonic radar to detect multiple targets multiplexed over a single free space channel via polarization division multiplexing (PDM). Also, the proposed system is tested for detection under zero visibility conditions under the impact of atmospheric turbulences up to 140 m of range distance. The reported results in terms of range frequency peaks and signal to noise ratio (SNR) indicate successful detection of both the targets at 4 GHz of bandwidth. The system is further tested for moving traffic condition with the target speed of 50 km/hr and 100 km/hr, respectively. Lastly, the range resolution of the proposed system is tested and reported as 15 cm at 1 GHz and 6.75 cm with 4 GHz of bandwidth at a distance of 100 m.