Active remote sensing using lock-in amplifiers and beam steering
AssigneeITT Manufacturing Enterprises, Inc.
InventorsMichael E. Dobbs, Allan Roberts
Life of this patent
Estimating the term…
Abstract
A remote sensing platform for sensing a target may include a source configured to emit optical radiation toward the target. A device may be configured to dither the emitted optical radiation to alternately illuminate a number of locations on the target. A first detector may be configured to detect radiation reflected from a first location of the number of locations and to generate a first signal. A first lock-in amplifier may be configured to process the first signal. A second detector may be configured to detect radiation reflected from a second location of the number of locations and to generate a second signal. A second lock-in amplifier may be configured to process the second signal.
Claims21
A remote sensing platform for sensing a target, comprising:
- a source disposed in an aircraft or satellite configured to emit optical radiation toward the target;
- a device configured to dither the emitted optical radiation to alternately illuminate a plurality of locations on the target;
- a first detector configured to detect radiation reflected from a first location of the plurality of locations and to generate a first signal;
- a first lock-in amplifier configured to process the first signal;
- a second detector configured to detect radiation reflected from a second location of the plurality of locations and to generate a second signal;
- and
- a second lock-in amplifier configured to process the second signal.
A method of remotely sensing a target, comprising:
- emitting a beam of optical radiation from a source disposed in an aircraft or satellite;
- deflecting the beam of optical radiation so that the optical radiation is alternately directed at a plurality of different locations on the target;
- detecting first radiation from one of the plurality of locations on the target using a phase sensitive technique;
- and
- detecting second radiation from another of the plurality of locations on the target using the phase sensitive technique.
A system for remotely sensing a target, comprising:
- a source configured to emit optical radiation;
- an amplifier configured to amplify the optical radiation emitted by the source to produce an amplified signal;
- a beam steering device configured to redirect the amplified signal at a predetermined frequency and transmit at least one chopped signal toward the target;
- and
- a first detecting unit configured to detect first radiation from the at least one chopped signal and generate a first detection signal based on the predetermined frequency of the beam steering device,
- wherein the beam steering device is configured to transmit substantially all power in the amplified signal toward the target, and
- the beam steering device is configured to transmit at least two chopped signals toward different portions of the target.
A method of remotely sensing a target, comprising:
- emitting a beam of optical radiation from a source disposed in an aircraft or satellite;
- steering the beam of optical radiation to transmit at least one chopped signal toward at least one location on the target, the at least one chopped signal including substantially all optical radiation in the beam of optical radiation;
- generating a reference signal corresponding to a frequency of the at least one chopped signal;
- and
- detecting first radiation from a first chopped signal of the at least one chopped signal using a phase sensitive technique and the reference signal;
- wherein the steering includes:
- alternately deflecting the beam of optical radiation toward first and second locations on the target to respectively generate the first chopped signal and a second chopped signal, and the first and second chopped signals are complementary, out-of-phase with respect to each other.
A method of remotely sensing a target, comprising:
- emitting a beam of optical radiation from a cw source disposed in an aircraft or satellite toward a position on a target;
- steering optical radiation reflected from the position on the target to generate a plurality of chopped signals;
- generating a reference signal corresponding to a frequency of the plurality of chopped signals;
- detecting first radiation from a first chopped signal of the plurality of chopped signals using a phase sensitive technique and the reference signal;
- and
- detecting second radiation from a second chopped signal of the plurality of chopped signals using the phase sensitive technique and the reference signal,
- wherein the first and second chopped signals are generated as complementary out-of-phase signals by the steering of the optical radiation reflected from the target.
Dependencies are inferred from the claim text.