Azimuth Velocity Estimation in Multi-Channel SAR Based on Variable-Boresight Mode

In order to overcome the disadvantage that traditional multichannel SAR systems are only sensitive to the radial velocities of moving targets, a variable-boresight mode has been proposed, whose kernel is to detect and estimate the velocity component of the azimuth velocity at two nodes. For purpose of improving the estimation accuracy of the azimuth velocity, we introduce more nodes with different squint angles, so as to obtain more velocity components to carry out the estimation by the least square method. Considering that only few tiny angles can be ignored, while introducing more nodes are likely to bring about nonnegligible squint angles, the previously used signal processing suitable for side-looking mode is modified. Finally, numerical experimental results are provided to verify the effectiveness.