| 摘要 |
<p>A method for detecting a flying animal whereby at least one transmitted signal is received, processed and filtered to provide a surveillance signal. An output signal is automatically controlled at a substantially constant level when the surveillance signal root mean squared value varies at a rate of change. The output signal is allowed to vary when the root mean squared value varies at a rate of change greater than said pre-defined threshold rate of change. Comparing the output signal against a predetermined value to provide an intruder detection signal indicative of the presence of a flying animal in the surveillance area.</p> |
