Controlling a line of sight angle of an imaging platform
Systems and methods of capturing imagery are provided. In particular, an imaging platform can be configured to capture imagery using a dual-axis steering mirror and one or more image capture devices. The line of sight angle of the imaging platform can be controlled by controlling the motion of the steering mirror in accordance with a motion profile. In example embodiments, the motion profile can correspond to a sawtooth wave. The imaging platform can further include one or more position sensors used to determine a position and/or orientation of the imaging platform along a path on which the imaging platform travels. The motion of the steering mirror can then be controlled to rotate about a first axis and a second axis to compensate for line of sight errors based at least in part on the determined position and/or orientation.
1. A computer-implemented method of controlling an imaging platform, the method comprising:
determining a motion profile for a dual-axis steering mirror associated with an imaging platform, wherein the motion profile is determined, at least in part, such that a line of sight angle of one or more imaging devices associated with the imaging platform changes to reduce or eliminate relative motion between the imaging platform and a region of interest;
controlling the motion of the dual-axis steering mirror based at least in part on the motion profile to capture a sequence of image frames of at least a portion of a region of interest during one or more integration time periods, wherein the motion profile controls the motion of the dual-axis steering mirror to rotate about a first axis and a second axis during the one or more integration time periods as the imaging platform travels along a path on which the imaging platform travels;
linking successive image frames together based on one or more overlapping regions within the sequence of image frames to form a reconstructed image; and
modifying the motion of the dual-axis steering mirror based on the motion profile, to rotate about the first axis and the second axis based on correcting one or more misalignments within the reconstructed image.
2. The computer-implemented method of claim 1 , wherein linking successive image frames together further comprises:
determining an amount of overlap within the one or more overlapping regions corresponding to a size capture area of a staring sensor; and
determining the one or more integration time periods such that the one or more integration time periods are spaced a distance apart to capture the sequence of image frames at a frequency that provides overlapping measurements the size of the capture area of the staring sensor.
3. The computer-implemented method of claim 1 , wherein linking successive image frames together further comprises:
determining an amount of overlap within the one or more overlapping regions corresponding to a frequency at which the image frames are captured; and
determining the one or more integration time periods such that the one or more integration time periods are spaced a distance apart to capture the sequence of image frames at the frequency, wherein a region of interest is overlapped among neighboring image frames.
4. The computer-implemented method of claim 1 , wherein linking successive image frames together further comprises:
determining an amount of overlap within the one or more overlapping regions corresponding to a distance between the imaging platform and a region of interest; and
determining the one or more integration time periods such that the one or more integration time periods are spaced a distance apart to capture the sequence of image frames at a frequency that provides overlapping measurements that are a size of the region of interest.
5. The computer-implemented method of claim 1 , wherein neighboring image fames are registered to provide the reconstructed image of a region of interest.
6. The computer-implemented method of claim 5 , wherein registration is based at least in part on a correlation of a portion of image data and an overlap between successive sub-images.
7. The computer-implemented method of claim 5 , wherein based on registering the neighboring image frames, deviations in the motion of the imaging platform from an expected direction of travel are corrected based on one or more misalignments within the reconstructed image.
8. The computer-implemented method of claim 1 , the computer-implemented method further comprising:
identifying blur in at least one of the captured image frames; and
controlling the motion of the dual-axis steering mirror based at least in part on identified blur, wherein controlling the motion of the dual-axis steering mirror comprises controlling the dual-axis steering mirror to rotate about a first axis and a second axis.
9. The computer-implemented method of claim 1 , wherein the motion profile comprises a sawtooth wave with one or more snapback segments according to which the dual-axis steering mirror is to be moved, and wherein the one or more snapback segments are determined such that the one or more integration time periods facilitate images captured at a frequency that provides overlapping measurements of a region of interest among neighboring image frames.
10. A computing system, comprising:
one or more processors; and
one or more memory devices, the one or more memory devices storing computer-readable instructions that when executed by the one or more processors cause the one or more processors to perform operations, the operations comprising:
determining a motion profile for a dual-axis steering mirror associated with an imaging platform, wherein the motion profile is determined, at least in part, such that a line of sight angle of one or more imaging devices associated with the imaging platform changes to reduce or eliminate relative motion between the imaging platform and a region of interest;
controlling the motion of the dual-axis steering mirror based at least in part on the motion profile to capture a sequence of image frames of at least a portion of a region of interest during one or more integration time periods, wherein the motion profile controls the motion of the dual-axis steering mirror to rotate about a first axis and a second axis during the one or more integration time periods as the imaging platform travels along a path on which the imaging platform travels;
linking successive image frames together based on one or more overlapping regions within the sequence of image frames to form a reconstructed image; and
modifying the motion of the dual-axis steering mirror to rotate about the first axis and the second axis based on correcting one or more misalignments within the reconstructed image.
11. The computing system of claim 10 , the operations further comprising:
determining an amount of overlap within the one or more overlapping regions corresponding to a size capture area of a staring sensor; and
determining the one or more integration time periods such that the one or more integration time periods are spaced a distance apart to capture the sequence of image frames at a frequency that provides overlapping measurements the size of the capture area of the staring sensor.
12. The computing system of claim 10 , the operations further comprising:
determining an amount of overlap within the one or more overlapping regions corresponding to a frequency at which the image frames are captured; and
determining the one or more integration time periods such that the one or more integration time periods are spaced a distance apart to capture the sequence of image frames at the frequency, wherein a region of interest is overlapped among neighboring image frames.
13. The computing system of claim 10 , the operations further comprising:
determining an amount of overlap within the one or more overlapping regions corresponding to a distance between the imaging platform and a region of interest; and
determining the one or more integration time periods such that the one or more integration time periods are spaced a distance apart to capture the sequence of image frames at a frequency that provides overlapping measurements that are a size of the region of interest.
14. The computing system of claim 10 , wherein neighboring image fames are registered to provide the reconstructed image of a region of interest.
15. The computing system of claim 14 , wherein registration is based at least in part on a correlation of a portion of image data and an overlap between successive sub-images.
16. The computing system of claim 14 , wherein based on registering the neighboring image frames, deviations in the motion of the imaging platform from an expected direction of travel are corrected based on one or more misalignments within the reconstructed image.
17. The computing system of claim 10 , the operations further comprising:
identifying blur in at least one of the captured image frames; and
controlling the motion of the dual-axis steering mirror based at least in part on identified blur, wherein controlling the motion of the dual-axis steering mirror comprises controlling the dual-axis steering mirror to rotate about a first axis and a second axis.
18. The computing system of claim 10 , wherein the motion profile comprises a sawtooth wave with one or more snapback segments according to which the dual-axis steering mirror is to be moved, and wherein the one or more snapback segments are determined such that the one or more integration time periods facilitate images captured at a frequency that provides overlapping measurements of a region of interest among neighboring image frames.
19. A computer-implemented method of controlling an imaging platform, the method comprising:
determining a motion profile for a dual-axis steering mirror associated with an imaging platform, wherein the motion profile is determined, at least in part, such that a line of sight angle of one or more imaging devices associated with the imaging platform changes to reduce or eliminate relative motion between the imaging platform and a region of interest, wherein the motion profile comprises a sawtooth wave with one or more snapback segments according to which the dual-axis steering mirror is to be moved;
controlling the motion of the dual-axis steering mirror based at least in part on the motion profile to capture a sequence of image frames of at least a portion of a region of interest during one or more integration time periods, wherein the motion profile controls the motion of the dual-axis steering mirror to rotate about a first axis and a second axis during the one or more integration time periods as the imaging platform travels along a path on which the imaging platform travels; and
linking successive image frames together based on one or more overlapping regions within the sequence of image frames to form a reconstructed image.
20. The computer-implemented method of claim 19 , wherein the one or more snapback segments are determined such that the one or more integration time periods facilitate images captured at a frequency that provides overlapping measurements of a region of interest among neighboring image frames.