초록 ▼

A laser radar system wherein a beam of continuous wave (CW) electromagnetic energy is generated with frequency modulation (FM) and amplitude modulation (AM) being imposed thereon to produce an amplitude and frequency modulated, continuous wave beam of energy. The AM-FM CW beam is transmitted toward

A laser radar system wherein a beam of continuous wave (CW) electromagnetic energy is generated with frequency modulation (FM) and amplitude modulation (AM) being imposed thereon to produce an amplitude and frequency modulated, continuous wave beam of energy. The AM-FM CW beam is transmitted toward a selected target, portions of the transmitted beam being reflected by the target and received along with portions of the transmitted beam reflected by unselected targets and atmospheric clutter. A first signal is produced in response to the frequency modulation on the received beam portions reflected by the selected target, such first signal representing the approximate range of the selected target and substantially resolving the selected target from unselected targets and atmospheric clutter and having a relatively long ambiguous range interval. A second signal is produced in response to the amplitude modulation on the received beam portions reflected by the selected target, the second signal representing the accurate range of the selected target within a relatively short ambiguous range interval. The second signal provides poor resolution between the selected target and the unselected targets and atmospheric clutter. The first and second signals are combined to produce an output signal having the relatively high resolution and long ambiguous range interval of the first signal and providing the accurate selected target range measurement of the second signal.

대표청구항 ▼

A laser radar system comprising: means for generating a beam of continuous wave electromagnetic energy, said generating means comprising means for producing a frequency and amplitude modulated beam of continuous wave electromagnetic energy, such producing means comprising: means for modulating the f

A laser radar system comprising: means for generating a beam of continuous wave electromagnetic energy, said generating means comprising means for producing a frequency and amplitude modulated beam of continuous wave electromagnetic energy, such producing means comprising: means for modulating the frequency of such continuous wave beam from a nominal frequency; and means for modulating the amplitude of such continuous wave beam from a nominal amplitude at a reference envelope frequency fm, said reference envelope having a reference phase; means for directing said frequency and amplitude modulated beam of energy toward a target; means for receiving portions of such directed beam of energy reflected by the target; means, responsive to the frequency modulation of the received portions of the frequency and amplitude modulated beam of energy, for producing a first signal representative of the approximate range of the target; and means responsive to the amplitude modulation of the received portions of the frequency and amplitude modulated beam of energy, for producing a second signal representative of variations in the approximate range of the target, said second signal producing means comprising: means, responsive to the received portions of target reflected energy, for producing a second amplitude modulated signal having a second envelope at the reference frequency fm; and means for comparing the phase of the reference envelope and the second envelope, with the phase difference therebetween being representative of variations in the approximate range of the target.