초록 ▼

A laser is provided for generating a beam of continuous wave (CW) electromagnetic energy having a nominal frequency and amplitude. The frequency of the CW beam is modulated (FM) from the nominal frequency. The amplitude of the frequency modulated beam is modulated (AM) from the nominal amplitude to

A laser is provided for generating a beam of continuous wave (CW) electromagnetic energy having a nominal frequency and amplitude. The frequency of the CW beam is modulated (FM) from the nominal frequency. The amplitude of the frequency modulated beam is modulated (AM) from the nominal amplitude to produce an amplitude and frequency modulated continuous wave (AM-FM CW) beam of energy. A local oscillator beam is produced from the frequency modulated CW beam. The AM-FM CW beam is directed for reflection by a target. The target-reflected return portions of the AM-FM CW beam are combined with the frequency modulated local oscillator beam to produce a beat frequency signal which is subsequently detected, the beat frequency signal having a frequency component representative of the range of the target. Such arrangement, when implemented in a radar system, provides such radar system with accurate target range measurements unambiguous over large ranges. Further, such AM-FM CW signal provides high resolution between target-reflected return signals of such AM-FM CW signal and returns from near-field atmospheric clutter.

대표청구항 ▼

In combination: means for generating a continuous wave beam of electromagnetic energy; means for modulating the frequency of the continuous wave beam of energy; means for splitting the frequency-modulated continuous wave beam of electromagnetic energy into a pair of beams; means for modulating the a

In combination: means for generating a continuous wave beam of electromagnetic energy; means for modulating the frequency of the continuous wave beam of energy; means for splitting the frequency-modulated continuous wave beam of electromagnetic energy into a pair of beams; means for modulating the amplitude of a first one of the pair of frequency modulated continuous wave beams and for directing said amplitude and frequency modulated continuous wave beam for reflection by a target; means for combining a second one of the pair of frequency modulated continuous wave beams with target-reflected portions of the amplitude and frequency modulated beam to produce a beat frequency signal; and means for detecting the beat frequency signal.