We discuss a coherent laser radar that uses two coherent femtosecond fiber lasers to perform absolute ranging at long distance. One coherent femtosecond fiber lasers acts as a source and the other as a local oscillator for heterodyne detection of the return signal from a cooperative target. The system simultaneously returns a time-of-flight range measurement for coarse ranging and an interferometric range measurement for fine ranging. Furthermore, it is insensitive to spurious reflections that can cause systematic errors. The range is measured with 3 m precision in 200 s and 5 nm precision in 60 ms over a 1.5 m ambiguity range. This ambiguity range can be extended to 30 km by simply reversing the roles of the signal and LO sources. We will also discuss the possibilities of using such a system for precision vibrometry and for even more rapid absolute ranging.
Proceedings Title: Coherent Laser Radar Conference, 2009
Conference Dates: June 22-26, 2009
Conference Location: Toulouse, -1
Pub Type: Conferences
absolute laser ranging, coherent lidar, frequency combs