| 摘要 |
1,251,859. Sonar systems. FRIED KRUPP G.m.b.H. 11 July, 1969 [12 July, 1968], No. 34989/69. Heading H4D. The rotatable transmitting beam of a sonar installation, for directional sounding in different directions numbered consecutively 1 to n, is switched successively to the directions n/2, n/ 2 +1, n/ 2 -1 n/ 2 +2, and so on (n being an even number). In the Fig. 2 embodiment m (=3) equi-spaced beams are oscillated together so that each scans n (=6) directions in the sequence 2.1, 2.2, 2.3 and so on. The invention is intended to make it easier, compared with the prior art Fig. 1 system, to compensate for the range distortion arising in a plan position indicating CRT display due to echoes from different directions but from objects at the same range being displayed on a spiral arc as a result of sounding pulses being transmitted non- simultaneously in the different directions: for Fig. 2 the range error varies smoothly round the circle, not discontinuously as for Fig. 1. Also, the invention reduces the likelihood of occurrence of two separated displays of one target detected in two beams e.g. beam 1a at position 2.1 and beam 1b at position 2.6. |
