| 摘要 |
The invention relates to a radar arrangement of the type comprising a transmitter which essentially continuously transmits a modulated carrier wave signal and a receiver for receiving the carrier wave signal reflected at an object (echo signal). The carrier wave signal is modulated with a code-generating signal (14) whose fundamental frequency, the code frequency, is determining for the range resolution of the radar. The code of the code-generating signal (14) is furthermore such that one bit in the code has a duration which is several times longer than the time of a period of the carrier wave signal and a code of several bits forms a block which is characterized by modulation of a carrier wave with constant frequency. The frequency of the carrier wave is changed between blocks so that the transmitter sends a block with a carrier wave frequency which is different from the carrier wave frequency or frequencies which the receiver is set up to receive. The receiver stores (14a) the transmitted code and correlates it with the received signal. When code correspondence (synchronism) is obtained this corresponds to a definitive position of the echo response reflector. By changing frequency between blocks, different range zones can be treated in different ways, that is to say different "types of radar" can be dedicated to different range zones. By this means, a radar arrangement is obtained which is adapted to cope with modern threat environments. The radar is difficult to spot, difficult to define and to disturb. |
