Multi-sampling-channel pulse compressor

A low-sidelobe pulse compression method for reducing the processing loss in echo signals caused by sampling time errors in pulse compression processing circuitry comprising the steps of:

• receiving an echo signal from an energy transmission;
• generating I and Q baseband signals from said echo signal;
• sampling said I and Q signals in accordance with pulses from a first clock signal having a predetermined sampling frequency and also sampling said I and Q signals in accordance with pulses from a second clock signal having said predetermined sampling frequency but with said second clock signal pulses interlaced, in time, approximately midway between the pulses of said first clock signal;
• compressing said first-clock-sampled I and Q signals and also compressing said second-clock-sampled I and Q signals;
• generating a first signal envelope from said compressed first-clock-sampled I and Q signals and a second signal envelope from said compressed second-clock-sampled I and Q signals;
• and
• multiplying said generated first and second signal envelopes together to obtain a low-sidelobe narrow output signal.

A low-sidelobe pulse compression processor for reducing the processing loss in echo signals caused by sampling time errors and for improving range resolution comprising:

• means for receiving an echo signal from an energy transmission and generating I and Q baseband signals from said echo signal;
• n signal processing channels, where n is an integer >2, wherein said first signal processing channel comprises:
• first sampling means for sampling said I and Q signals in accordance with pulses from a first clock signal having a predetermined sampling frequency;
• first means for compressing said I and Q signals from first sampling means;
• first means for generating the signal envelope for said compressed I and Q signals from said first compressing means;
• and wherein said i th signal processing channel, where 1.ltoreq.i.ltoreq.n, comprises:
• i th sampling means for sampling said I and Q signals in accordance with pulses from an i th clock signal having said predetermined sampling frequency but with said i th clock pulses interlaced, in time, with said first clock signal pulses such that said i th clock signal pulses are (i) (360.degree.)/(n) out of phase with said first clock pulses;
• i th means for compressing said i th clock sampled I and Q signals from said i th sampling means;
• i th means for generating the signal envelope for said compressed I and Q signals from said i th compressing means;
• and
• multiplying means for multiplying together the output envelope signals generated in each of said n signal processing channels to obtain a low-sidelobe narrow output signal.