Determining angular rate for line-of-sight to a moving object, with a body-fixed imaging sensor

A method for estimating line-of-sight rotation rate for use in tracking, approaching, pursuing, intercepting, or avoiding an object;

• said method comprising the steps of:
• operating at least one inexpensive and low-quality inertial rate sensor, to establish a first relatively rough but efficient embedded image registration and mapping;
• based on the first registration, generating a homography matrix;
• with an imaging sensor fixed to a vehicle that is approaching or receding from the object, recording a series of images of the object together with a background;
• based on computations made from the images exclusively, with no direct information about gimbal angle, and with no direct information about inertial angular body rate except as stated in the sensor-operating step above, estimating line-of-sight rotation rate of the object relative to the vehicle;
• and
• applying the estimated line-of-sight rotation rate to track, approach, pursue, intercept or avoid the object;
• wherein the estimating step further comprises the substeps of:
• evaluating the optical flow between successive frames,
• next selecting anchor points for image sequences;
• and
• then applying a second, relatively finer image-registration technique to establish an output image-registration solution;
• wherein the registration solution is a coordinate translation for aligning the inertial surroundings of the object.

Apparatus for estimating line-of-sight rotation rate for use in tracking, approaching, pursuing, intercepting or avoiding an object;

• said apparatus comprising:
• at least one imaging sensor fixed to a vehicle that is approaching or receding from the object, wherein the vehicle is not a part of the claimed apparatus;
• means for controlling the at least one sensor to record a series of images of such object together with a background;
• means for making computations derived exclusively from the images, with no direct information about inertial angular body rate or gimbal angle, and for thereby estimating line-of-sight rotation rate of such object relative to such vehicle;
• and
• means for applying the estimated line-of-sight rotation rate to track, approach, pursue, intercept or avoid such object.

Apparatus for estimating line-of-sight rotation rate for use in tracking, approaching, pursuing, intercepting or avoiding an object;

• said apparatus comprising:
• a vehicle approaching or receding from such object;
• at least one imaging sensor fixed to the approaching or receding vehicle;
• means for controlling the sensor to record a series of images of such object together with a background;
• means for making computations derived exclusively from the images, with no direct information about inertial angular body rate or gimbal angle, and for thereby estimating line-of-sight rotation rate of such object relative to the vehicle;
• and
• means for applying the estimated line-of-sight rotation rate to track, approach, pursue, intercept or avoid such object.