System and method of three-dimensional imaging
Systems and methods for three-dimensional imaging are disclosed. A three-dimensional imaging system may include a light source to emit a light pulse. The divergence of the light pulse may be configurable by the system. For example, the system may also include a receiving lens having a field of view and configured to receive a portion of the light pulse reflected or scattered by a scene. The system may configure the light source so that the divergence of the light pulse matches or approximates the field of view of the receiving lens.
1. A three-dimensional imaging system, comprising:
a light source configured to emit a first light pulse and a second light pulse, each with a predetermined divergence sufficient to irradiate a scene;
a receiving lens configured to receive a first received light portion of the first light pulse reflected or scattered by the scene and a second received light portion of the second light pulse reflected or scattered by the scene;
a modulator, located within the receive path, configured to modulate as a function of time intensities of the first and second received light pulse portions to form, respectively, first and second modulated received light pulse portions, in which a first portion of the first modulated received light pulse portion is below a focal plane array (FPA) saturation limit and a second portion of the second modulated received light pulse portion is above the FPA saturation limit; and
a processor subsystem configured to generate a 3D image of the scene based on combination of the second portion of the second modulated received light pulse portion that is above the FPA saturation limit with the first portion of the first modulated received light pulse portion that is below the FPA saturation limit.
2. The three-dimensional imaging system of claim 1 , in which the scene comprises one or more objects, in which a first subset of the one or more objects are resolved based on an illumination level of the first portion of the first modulated received light pulse portion being below the FPA saturation limit, and a second subset of the one or more objects are insufficiently resolved based on the illumination level of the first portion of the first modulated received light pulse portion being below the FPA saturation limit.
3. The three-dimensional imaging system of claim 2 , further comprising a controller configured to transmit a control signal to the light source, the control signal configured to increase the illumination level of the first portion of the first modulated received light pulse portion to establish the second portion of the second modulated received light pulse portion that and resolve the second subset of the one or more objects.
4. The three-dimensional imaging system of claim 1 , in which the first and second portions provide, respectively, first and second 3D images.
5. The three-dimensional imaging system of claim 1 , further comprising a controller configured to transmit a control signal to the light source, the control signal configured to adjust an external attenuator to attenuate an energy level corresponding to one of the first and second light pulse to establish a different one of the first and second light pulse.
6. The three-dimensional imaging system of claim 1 , in which a duration of the light pulse is less than two nanoseconds.
7. The three-dimensional imaging system of claim 1 , in which the light source comprises a low-coherence laser configured to generate light containing a number of modes sufficient to produce a smooth spatial profile.
8. The three-dimensional imaging system of claim 1 , in which the light pulse comprises visible wavelengths, near-infrared wavelengths, or a combination thereof.
9. The three-dimensional imaging system of claim 1 , in which the light pulse comprises a substantially uniform spatial profile.
10. The three-dimensional imaging system of claim 1 , in which the scene comprises one or more objects, a first subset of the one or more objects are imaged with low resolution based at least on a low signal to noise ratio (SNR) attributable to the first portion of the first modulated received light pulse portion, a second subset of the one or more objects are imaged with high resolution based at least on a high SNR attributable to the second portion of the second modulated received light pulse portion.
11. The three-dimensional imaging system of claim 1 , further comprising optics configured to set the predetermined divergence to approximately match a field of view of the receiving lens.