Angle Estimation for Bistatic MIMO Radar With a Sparse Moving Array in the Presence of Position Errors and Gain-Phase Perturbation

We recently extended the degrees of freedom for the bistatic multiple-input multiple-output (MIMO) radar by exploiting sparse array motion at the receiver part, and considered the sensor position errors arising from array motion. However, this technique does not consider the sensor position errors along the x-axis and the y-axis, nor the gain-phase errors of the sparse moving array. There are also spurious results during the angle estimation. This article extends the one-dimensional sensor position errors to the case of two-dimensional errors generated by the array motion and considers the gain-phase perturbation of the sparse moving array, which is inevitable on the moving platform. We first use a dedicated calibration source to estimate the gain-phase errors and compensate for the received data to obtain accurate angle estimates. We get the angle estimates by two approaches: one relies on the calibration source, and the other resorts to self-calibration processing. We also introduce an unfolded coprime linear array at the receiver part, which avoids spurious results and increases the array aperture. The ambiguous solutions of the proposed methods are theoretically analyzed, and the Cramer-Rao bound of angle estimate errors in the presence of sensor position errors is derived. Finally, numerous simulation results show that our methods can achieve superior estimation performance under the aforementioned errors.