Scanned laser imaging and ranging system

Claim 2

In a scanned laser radar imaging system of the type utilizing a gas laser to generate an output of continuous wave radiant energy which is reflected from a scanned scene to produce an image thereof, the improvement comprising: a. first means to pulse said laser during predetermined discrete time intervals to vary a characteristic of said laser output during said discrete intervals to thereby produce output pulses distinguishable from said continuous wave output during said time intervals in terms of said varied characteristic; b. second means to separate said reflected radiant energy into first and second portions; c. third means to utilize said first portion of said reflected energy from said continuous wave output to produce said image of said scene; and d. fourth means to simultaneously utilize said second portion of said reflected energy from said output pulses of varied characteristic to determine the range to a predetermined portion of said imaged scene.

Claim 3

Apparatus as in claim 1 and further including means responsive to coincident reception of reflected energy from both said continuous wave output and said pulse output of said laser to enhance the fidelity of at least one of said utilizatIon means.

Claim 4

Apparatus as in claim 1 and further including means responsive to reception of reflected energy from said pulse output of said laser to control the phase synchronization of said scene to produce said image.

Claim 5

Apparatus as in claim 1 wherein said varied characteristic of said laser output is its amplitude, said pulses having an amplitude which is distinguishably greater than that of the steady state amplitude of said continuous wave output.

Claim 6

In a scanned laser radar imaging system of the type utilizing a gas laser to generate an output of continuous wave radiant energy which is reflected from a scanned scene to produce an image thereof, the improvement comprising: a. first means to pulse said laser during predetermined discrete time intervals to vary a characteristic of said laser output during said discrete intervals to thereby produce output pulses distinguishable from said continuous wave output during said time intervals in terms of said varied characteristic; b. second means to separate said reflected radiant energy into first and second portions; c. third means to utilize said first portion of said reflected energy from said continuous wave output to produce said image of said scene; and d. fourth means to simultaneously utilize said second portion of said reflected energy from said output pulses of varied characteristic to determine the range to a predetermined portion of said imaged scene, said varied characteristic of said laser output being its wavelength, said continuous wave output being at a first wavelength and said pulse output being at a second wavelength which occurs only during said pulse and which is then separate and different from said first wavelength output coexisting therewith.

Claim 7

In a scanned laser radar imaging system of the type utilizing a gas laser to generate an output of continuous wave radiant energy which is reflected from a scanned scene to produce an image thereof, the improvement comprising: a. first means to pulse said laser during predetermined discrete time intervals to vary a characteristic of said laser output during said discrete intervals to thereby produce output pulses distinguishable from said continuous wave output during said time intervals in terms of said varied characteristic; b. second means to separate said reflected radiant energy into first and second portions; c. third means to utilize said first portion of said reflected energy from said continuous wave output to produce said image of said scene; and d. fourth means to simultaneously utilize said second portion of said reflected energy from said output pulses of varied characteristic to determine the range to a predetermined portion of said imaged scene, said varied characteristic of said laser output being its wavelength, said continuous wave output being at a first wavelength and said pulse output being at a second wavelength which occurs only during said pulse and which is then separate and different from said first wavelength output coexisting therewith.

Claim 8

In a scanned laser radar imaging system of the type utilizing a gas laser to generate an output of continuous wave radiant energy which is reflected from a scanned scene to produce an image thereof, the improvement comprising: a. first means to pulse said laser during predetermined discrete time intervals to vary a characteristic of said laser output during said discrete intervals to thereby produce output pulses distinguishable from said continuous wave output during said time intervals in terms of said varied characteristic; b. second means to separate said reflected radiant energy into first and second portions; c. third means to utilize said first portion of said reflected energy from said continuous wave output to produce said image of said scene; and d. fourth means to simultaneously utilize said second portion of said reflected energy from said output pulses of varied characteristic to determine the range to a predetermined portion of said imaged scene, said predetermined portion of said imaged scene to which range is determined being an operator selected target and said apparatus including means to trigger said first pulsing means only at a time during each scan of said scene such that said pulse of varied characteristic is reflected from said target.

Claim 9

In a scanned laser radar imaging system of the type utilizing a gas laser to generate an output of continuous wave radiant energy which is reflected from a scanned scene to produce an image thereof, the improvement comprising: a. first means to pulse said laser during predetermined discrete time intervals to vary a characteristic of said laser output during said discrete intervals to thereby produce output pulses distinguishable from said continuous wave output during said time intervals in terms of said varied characteristic; b. second means to separate said reflected radiant energy into first and second portions; c. third means to utilize said first portion of said reflected energy from said continuous wave output to produce said image of said scene; and d. fourth means to simultaneously utilize said second portion of said reflected energy from said output pulses of varied characteristic to determine the range to a predetermined portion of said imaged scene, said predetermined portion of said imaged scene to which range is determined being an operator selected target and said apparatus including means to trigger said first pulsing means only at a time during each scan of said scene such that said pulse of varied characteristic is reflected from said target.

Claim 10

Apparatus as in claim 1 wherein said predetermined portion of said imaged scene to which range is determined is a plurality of incrementally separated elements of said scene positioned throughout each scan of said scene so as to provide samples of the contour of the terrain of the scene imaged and wherein said apparatus further includes means to automatically control the timing of said first pulsing means to produce a plurality of pulses during each scan of said scene to be reflected from said plurality of said contour sampled elements of said scene.

Claim 11

A scanned laser radar imaging system for simultaneously producing an image of a scanned scene and determining the range to a predetermined portion of said scene comprising: a. a laser operative to generate an output of continuous wave radiant energy, said laser comprising a gas laser having a continuous wave output at a first wavelength when operated at a first steady state level oF power input and capable of simultaneously generating both said first wavelength output and a second output at a second wavelength when operated at a predetermined increased level of power input to said laser; b. transmitter optics and scanner means operative to transmit said output and direct it onto a scene to be scanned in a predetermined timed scan pattern; c. means to derive at least one time synchonization signal from said scanner means; d. pulser means to vary a characteristic of said transmitted output of said continuous wave laser in pulses occurring at preselected times, said pulser comprising means operative to increase the power level of said input to said laser to said predetermined increased level to generate pulses at said second wavelength for transmission simultaneously with said continuous wave output at said first wavelength; e. means to control said preselected times relatively to said synchronization signal; f. receiver optics for receiving said laser generated energy which is reflected from said scanned scene; g. receiver output processing means to process the output of said receiver optics to derive from it a first signal comprising an image signal which is a measure of the reflectivity of elements of said scanned scene as represented by the reflected continuous wave energy of said laser and a second signal comprising a range signal which affords a measure of the transit time of the energy relected from said predetermined portion of said image during said timed pulses, said receiver output processing means comprising a first optical path for selectively transmitting only energy at said first wavelength to first electro-optical transducer means for generating said first signal and a second optical path for selectively transmitting only energy at said second wavelength to a second electro-optical transducer for generating said second signal; h. means responsive to said synchronization signal and to said first signal from said receiver output processing means for generating an image of said scanned scene; and i. counter means connected to measure the time elapsed between said preselected time of occurrence of a pulse of said transmitted output and the time of reception of said second signal from said receiver output processing means derived from the reflected energy of said pulse for computing the range from said transmitter to said predetermined portion of said scene.

Claim 12

A scanned laser radar imaging system for simultaneously producing an image of a scanned scene and determining the range to a predetermined portion of said scene comprising: a. a laser operative to generate an output of continuous wave radiant energy, said laser comprising a gas laser having a continuous wave output at a first wavelength when operated at a first steady state level oF power input and capable of simultaneously generating both said first wavelength output and a second output at a second wavelength when operated at a predetermined increased level of power input to said laser; b. transmitter optics and scanner means operative to transmit said output and direct it onto a scene to be scanned in a predetermined timed scan pattern; c. means to derive at least one time synchonization signal from said scanner means; d. pulser means to vary a characteristic of said transmitted output of said continuous wave laser in pulses occurring at preselected times, said pulser comprising means operative to increase the power level of said input to said laser to said predetermined increased level to generate pulses at said second wavelength for transmission simultaneously with said continuous wave output at said first wavelength; e. means to control said preselected times relatively to said synchronization signal; f. receiver optics for receiving said laser generated energy which is reflected from said scanned scene; g. receiver output processing means to process the output of said receiver optics to derive from it a first signal comprising an image signal which is a measure of the reflectivity of elements of said scanned scene as represented by the reflected continuous wave energy of said laser and a second signal comprising a range signal which affords a measure of the transit time of the energy relected from said predetermined portion of said image during said timed pulses, said receiver output processing means comprising a first optical path for selectively transmitting only energy at said first wavelength to first electro-optical transducer means for generating said first signal and a second optical path for selectively transmitting only energy at said second wavelength to a second electro-optical transducer for generating said second signal; h. means responsive to said synchronization signal and to said first signal from said receiver output processing means for generating an image of said scanned scene; and i. counter means connected to measure the time elapsed between said preselected time of occurrence of a pulse of said transmitted output and the time of reception of said second signal from said receiver output processing means derived from the reflected energy of said pulse for computing the range from said transmitter to said predetermined portion of said scene.

Claim 13

Apparatus as in claim 8 wherein: a. said means to control said preselected times of said output pulses comprises operator controlled means to select a visually predetermined target element of said image of said scanned scene and to generate a signal which is a measure of its position in said timed scan pattern; and b. means to utilize said second signal derived from said receiver output processing means to compute the range to said operator selected target element.

Claim 14

Apparatus as in claim 8 wherein: a. said means to control said preselected times of output pulses comprises means to automatically generate a plurality of incrementally spaced pulser timing control signals during each scan of said scene, said pulser timing control signals being related to said timed scan pattern in a predetermined manner; and b. means to utilize said second signal derived from said receiver output processing means to compile a contour map of the terrain of said scanned scene by computing and storing a measure of the range to each of the elements of said scene illuminated by said pulsed output.

Claim 15

Apparatus as in claim 9 and further including means to modify said first image signal derived from said receiver output processing means only during reception of said second range signal derived therefrom, said first signal being modified in such a manner as to compensate for the distortion of the imaging of the reflectivity of said scene due to said increase in the power level of the input to said laser during said pulse.

Claim 16

In a scAnned laser radar imaging system of the type utilizing a gas laser to generate an output of continuous wave radiant energy which is reflected from a scanned scene to display an image thereof: a. means to utilize a portion of the output energy of said laser to determine the range to at least one element of said imaged scene simultaneously with the display of said image, said portion of the output energy being generated by means to pulse said continuous wave laser to produce during said pulse interval both said continuous wave output at a first wavelength and a pulse output at a second wavelength; and b. means to provide a readout of said range to a designated element of said scene.

Claim 17

In a scAnned laser radar imaging system of the type utilizing a gas laser to generate an output of continuous wave radiant energy which is reflected from a scanned scene to display an image thereof: a. means to utilize a portion of the output energy of said laser to determine the range to at least one element of said imaged scene simultaneously with the display of said image, said portion of the output energy being generated by means to pulse said continuous wave laser to produce during said pulse interval both said continuous wave output at a first wavelength and a pulse output at a second wavelength; and b. means to provide a readout of said range to a designated element of said scene.

Claim 18

In a scanned laser radar imaging system of the type utilizing a gas laser to generate an output of continuous wave radiant energy which is reflected from a scanned scene to display an image thereof: a. means to utilize a portion of the output energy of said laser to determine the range to at least one element of said imaged scene simultaneously with the display of said image; and b. operator actuated means to provide a readout of said range to a designated element of said scene, said operator actuated means comprising means to fire a pulse of laser output energy at said designated element and means to compute the magnitude of said range from the transit time of the reflection of said pulse.

Claim 19

In a scanned laser radar imaging system of the type utilizing a gas laser to generate an output of continuous wave radiant energy which is reflected from a scanned scene to display an image thereof: a. means to utilize a portion of the output energy of said laser to determine the range to at least one element of said imaged scene simultaneously with the display of said image; and b. operator actuated means to provide a readout of said range to a designated element of said scene, said operator actuated means comprising means to fire a pulse of laser output energy at said designated element and means to compute the magnitude of said range from the transit time of the reflection of said pulse.

Claim 20

Apparatus as in claim 12 wherein said range readout means comprises means to compute and store values of range to a plurality of incrementally space elements of said scene and means to designate the image coordinates of one element of said scene for which said range readout is to be provided from a corresponding address in said plurality of stored values of range.