| 摘要 |
The invention provides a method of determining the range of a radar signal reflecting object by utilizing a radar frequency carrier wave modulated by a first short code having a first repetition rate and a second code having a bit rate equal to the first code repetition rate. A received echo is first passed to an analogue correlator for correlation against a delayed version of the first code, and the output of the analogue correlator is fed to a digital correlator for correlation therein against the second code. In this way, the high bandwidth (greater range resolution) of analogue correlation can be combined with the lower bandwidth (longer ambiguity function) of digital correlation to provide high resolution target detection without ambiguity and at a fast rate without the need for a very large number of correlators. |
