Patent ID: 8552350

Claim:
An imaging vehicle, comprising: a frame; a propulsion system mounted to the frame; a main IMU coupled to measure 6-axis rigid body motion of the vehicle's frame, said 6-axis rigid body motion including linear accelerations in x, y and z directions and angular rates of change of roll, pitch and yaw about the respective x, y and z axes; a compliant isolator mounted to the frame; a detector assembly for capturing images of scene, said assembly including an isolated sub-assembly comprising a telescope and a detector mounted on said compliant isolator, said isolator and isolated sub-assembly having a resonant frequency between 5 Hz and 5 kHz to partially isolate said sub-assembly from attitude noise of the rigid body motion of the frame, said isolation inducing a pseudo-motion in yaw and pitch between the detector assembly and the frame; at least two secondary rate sensors that exhibit a time-varying drift in their measurements, said secondary rate sensors coupled to output secondary measurements of the angular rate of change in yaw and pitch of the isolated sub-assembly, said secondary measurements comprising a rigid body motion component, a time-varying drift component and a pseudo-motion component; and a computer that uses the main IMU's yaw and pitch measurements as a reference to remove the rigid body motion component from the secondary measurements of yaw and pitch to generate yaw and pitch difference signals, implements an estimator that processes the difference signals to generates estimates of the time-varying drift component for yaw and pitch, and subtracts the estimates from the secondary measurements of yaw and pitch to produce corrected secondary measurements of yaw and pitch that include the rigid body motion component and pseudo-motion component, said computer processing measurements of the 6-axis rigid body motion and the corrected measurements of the angular rate of change in yaw and pitch of the isolated sub-assembly to estimate a 6-axis position in x, y and z and attitude in roll, pitch and yaw of the isolated sub-assembly.