| 摘要 |
There is a need for apparatus which simulates signals received by a radar antenna. Such apparatus is needed for testing radar equipment and for training purposes.
<??>Hitherto it has not been possible to simulate accurately signals which are likely to occur in a real-life situation where a three dimensional radar is being used to detect numerous objects some of which may be moving, some of which may be emitters of radiation and some of which may merely reflect radiation emitted by the radar. These needs are met by the illustrated apparatus in which the trajectories of the objects are recorded in a computer (1). The positions of the objects at any one time are held in a store (3) from which azimuth and elevation signals (G,G min ) are read out. Two stores (5,5 min ) hold respectively the horizontal and vertical polar diagram characteristics of an antenna. The appropriate values are read out of these stores by the signals (G,G min ) and the outputs from the stores are combined to give a final attenuation signal (J) which is used to control the amplitude of an R.F. signal thereby producing a realistic simulated signal.
<??>The polar diagram characteristics of an antenna may be different for transmission and reception. To take this into account each store (5,5 min ) may have a duplicate (9,9 min ), the outputs from all four stores being combined to produce the simulated signal.
|
