STAP for Airborne Radar Based on Dual-Frequency Space-Time Coprime Sampling Structure

Abstract

To overcome the space-time adaptive processing (STAP) performance loss caused by discarding the non-uniform parts of difference coarray and copulse for coprime sampling structure under the condition of single-frequency operation, this paper proposes a new STAP algorithm to improve the precision of filter weight vector estimation by the dual-frequency operation. By selecting a single proper additional operation frequency, we can obtain the different coarray and copulse, thus fill two missed virtual sensors and pulses of the difference structures in the single-frequency operation simultaneously. Compared with the single-frequency operation, the dual-frequency operation method can acquire the bigger uniform linear array (ULA) and coherent processing interval (CPI) pulse train to improve the system degrees of freedom (DOF), and result in higher angle-Doppler resolution. In addition, the coprime array has the little mutual coupling effect because of the larger inter-sensors spacing. Therefore, the resulting method can alleviate mutual coupling and enhance the system DOF. INDEX TERMSCoprime sampling structure, degrees of freedom, dual-frequency operation, space-time adaptive processing, mutual coupling.

A Novel Fast Iterative STAP Method with a Coprime Sampling Structure

“…Common sparse arrays include minimal redundancy arrays [ 23 , 24 ], nested arrays [ 5 , 25 , 26 , 27 ], and coprime arrays [ 5 , 28 , 29 , 30 , 31 ]. Minimally redundant arrays provide the largest contiguous array for a given number of sensors, but lack closed expressions for sensor locations and DOF.…”

A Novel MIMO Array with Reduced Mutual Coupling and Increased Degrees of Freedom

“…e problem of array structure for the colocated MIMO radar has received considerable attention recently. Currently, most open literatures mainly have focused on research of the sparse arrays with closed expressions such as nested arrays [8][9][10], coprime arrays [11][12][13][14][15][16][17], and minimum redundancy arrays [18,19]. ey can offer a longer virtual aperture compared to uniform linear arrays (ULA) by utilizing second-order statistics of the received data.…”