Bulk optics for a scanning array
A multispectral sensor array can include a combination of ranging sensor channels (e.g., LIDAR sensor channels) and ambient-light sensor channels tuned to detect ambient light having a channel-specific property (e.g., color). The sensor channels can be arranged and spaced to provide multispectral images of a field of view in which the multispectral images from different sensors are inherently aligned with each other to define an array of multispectral image pixels. Various optical elements can be provided to facilitate imaging operations. Light ranging/imaging systems incorporating multispectral sensor arrays can operate in rotating and/or static modes.
1. A scanning imaging system for providing an image having a fixed resolution in a scanning direction, the scanning imaging system comprising:
a sensor array comprising a set of sensor channels arranged in two dimensions, each of the sensor channels being configured to detect light;
a rotary control system configured to rotate the sensor array in a scanning direction through a sequence of angular measurement positions to obtain a frame of data, the frame of data representing an image of a field of view, the frame of data comprising a grid of image pixels spaced in the scanning direction according to a uniform angular pitch; and
a bulk optic module configured to focus the light toward the sensor array, the bulk optic module having a focal length and a focal length distortion profile that are both tuned to the arrangement of the set of sensor channels such that rotating the sensor array through the uniform angular pitch along the scanning direction shifts a location where a ray is incident on the sensor array from one sensor channel to an adjacent sensor channel.
2. The scanning imaging system of claim 1 wherein the set of sensor channels includes a staggered grid of LIDAR sensor channels defining a column that extends in a direction transverse to the scanning direction.
3. The scanning imaging system of claim 2 wherein the set of sensor channels further includes at least one ambient-light sensor channel disposed along the scanning direction relative to each of the LIDAR sensor channels.
4. The scanning imaging system of claim 2 wherein the set of sensor channels further includes a plurality of ambient-light sensor channels disposed along the scanning direction relative to each of the LIDAR sensor channels.
5. The scanning imaging system of claim 1 wherein the sensor array has a fixed pitch between adjacent sensor channels along the scanning direction, and wherein the bulk optic module has an F θ focal length distortion profile.
6. The scanning imaging system of claim 1 wherein the sensor array has a fixed pitch between adjacent sensor channels along the scanning direction, and wherein the bulk optic module has an F tan θ focal length distortion profile.
7. The scanning imaging system of claim 1 wherein the focal length distortion profile of the bulk optic module exhibits barrel distortion and wherein a distance between adjacent sensor channels in the sensor array increases from an edge to a center of the sensor array.
8. The scanning imaging system of claim 1 wherein the focal length distortion profile of the bulk optic module exhibits pincushion distortion and wherein a distance between adjacent sensor channels in the sensor array decreases from an edge to a center of the sensor array.
9. A scanning imaging system for providing an image having a fixed resolution in a scanning direction, the scanning imaging system comprising:
a sensor array comprising a set of sensor channels arranged in one or two dimensions, each of the sensor channels being configured to detect light;
a mirror subsystem configured to direct light from different portions of a field of view onto the sensor array at different times such that the sensor array obtains a frame of data representing an image of the field of view, the frame of data comprising a grid of image pixels spaced in a scanning direction according to a uniform angular pitch; and
a bulk optic module configured to focus the light toward the sensor array, the bulk optic module having a focal length and a focal length distortion profile that are both tuned to the arrangement of the set of sensor channels such that rotating the sensor array through the uniform angular pitch along the scanning direction shifts a location where a ray is incident on the sensor array from one sensor channel to an adjacent sensor channel.
10. The scanning imaging system of claim 9 wherein the set of sensor channels includes a staggered grid of LIDAR sensor channels defining a column that extends in a direction transverse to the scanning direction.
11. The scanning imaging system of claim 10 wherein the set of sensor channels further includes at least one ambient-light sensor channel disposed along the scanning direction relative to each of the LIDAR sensor channels.
12. The scanning imaging system of claim 10 wherein the set of sensor channels further includes a plurality of ambient-light sensor channels disposed along the scanning direction relative to each of the LIDAR sensor channels.
13. The scanning imaging system of claim 9 , wherein the sensor array has a fixed pitch between adjacent sensor channels along the scanning direction, and wherein the bulk optic module has an F θ focal length distortion profile.
14. The scanning imaging system of claim 9 , wherein the sensor array has a fixed pitch between adjacent sensor channels along the scanning direction, and wherein the bulk optic module has an F tan θ focal length distortion profile.
15. The scanning imaging system of claim 9 , wherein the focal length distortion profile of the bulk optic module exhibits barrel distortion and wherein a distance between adjacent sensor channels in the sensor array increases from an edge to a center of the sensor array.
16. The scanning imaging system of claim 9 , wherein the focal length distortion profile of the bulk optic module exhibits pincushion distortion and wherein a distance between adjacent sensor channels in the sensor array decreases from an edge to a center of the sensor array.
17. A raster-scanning imaging system for providing an image having a fixed resolution by scanning in two dimensions, the raster-scanning imaging system comprising:
a sensor array comprising a set of sensor channels arranged in one or two dimensions, each of the sensor channels being configured to detect light;
a raster scanning mechanism configured to perform a raster scan in one or two dimensions that directs light from different portions of a field of view onto the sensor array at different times such that the sensor array obtains a frame of data representing an image of the field of view, the frame of data comprising a two-dimensional grid of image pixels spaced in each of the two dimensions according to a uniform pitch, wherein both dimensions of the grid of image pixels are larger than the dimensions of the sensor array; and
a bulk optic module configured to focus the light toward the sensor array, the bulk optic module having a focal length and a focal length distortion profile that are both tuned to the arrangement of the set of sensor channels such that the sensor array uniformly samples the field of view.
18. The raster-scanning imaging system of claim 17 wherein the raster scanning mechanism moves the sensor array in two dimensions.
19. The raster-scanning imaging system of claim 17 wherein the raster scanning mechanism includes a tip-tilt mirror movable in two dimensions to direct light from different portions of a field of view onto the sensor array at different times.
20. The raster-scanning imaging system of claim 17 wherein the sensor channels include LIDAR sensor channels.
21. The raster-scanning imaging system of claim 17 wherein the sensor channels include one or more hybrid sensor channels, each hybrid sensor channel comprising:
a plurality of photosensors; and
a patterned optical filter wherein different portions of the patterned optical filter selectively pass light having different properties,
the patterned optical filter being arranged such that different ones of the plurality of photosensors receive light having different properties,
the patterned optical filter being further arranged such that a first subset of the plurality of photosensors receives infrared light within a narrow passband matched to a wavelength of a LIDAR emitter and a second subset of the plurality of photosensors receives visible light from at least a portion of a visible light spectrum.
22. The raster-scanning imaging system of claim 17 wherein the sensor channels include one or more hybrid sensor channels, each hybrid sensor channel comprising:
a LIDAR sensor channel disposed on a first sensor channel layer;
an aperture layer overlying the first sensor channel layer and having an aperture therein to allow light to enter the LIDAR sensor channel; and
a plurality of ambient-light sensor channels disposed on at least a portion of the aperture layer around the aperture, each ambient-light sensor channel including a photosensor and an optical filter that selectively passes light having a specific property, wherein the optical filters of different ones of the ambient-light sensor channels selectively pass light having different properties.
23. The raster-scanning imaging system of claim 17 wherein the sensor array has a fixed pitch between sensor channels and wherein the bulk optic module has an F tan θ focal length distortion profile.
24. The raster-scanning imaging system of claim 17 wherein the sensor array has a fixed pitch between sensor channels and wherein the bulk optic module has an F θ focal length distortion profile.