| 摘要 |
Apparatus and method for providing increased gains in detection and classification of active sonar targets while concurrently preventing target cognizance of detection. Operation starts with transmission of a sequence of FM slides as subpulses alternately up slide, down slide, up slide, etc., while varying randomly the start frequency of each. Subpulse lengths short enough to avoid overlap of echoes from multiple major reflectors are used. Each slide is started at a randomized frequency. Just enough bandwidth is used on each slide to achieve the range resolution desired for searching. Considering only the individual subpulse bandwidth, subpulses are transmitted throughout the systems total bandwidth. Enough subpulses are transmitted to achieve the bandwidth/time product desired for searching.
|
