Inertial navigation system for radar terrain imaging

What is it about?

Synthetic Aperture Radars (SAR) enable synthesis of high-resolution terrain images on the basis of radar signals transmitted and received from a moving platform (aircraft, UAV, satellite). This paper addresses the system installed on a mini UAV. For simplicity of image synthesis, the platform should move with a constant velocity and follow a straight flight path. In the case of a mini-UAV, due to its small size, weight and velocity, maintaining the rectilinear trajectory, in the unstable atmosphere, is not possible. To compensate for these effects, the flight path deviations from an assumed straight line should be estimated and position corrections should be used to correct the phase of the received echo signal in order to get a focused SAR images. The paper describes a high-accuracy navigation system elaborated by the authors to estimate such corrections and presents effects of its use on SAR images.

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Why is it important?

Compensation of UAV motion instabilities in the process of creation of radar images in Synthetic Aperture Radars (SAR) can significantly improve their quality. Our high-accuracy navigation system described in the paper enables significant reduction of distortions and blurrings of SAR images, which is demonstrated in the images included in the paper.