Wideband cognitive radar waveform optimization for joint target radar signature estimation and target detection

Abstract

As the target radar signature (TRS) is target-radar orientation sensitive and time varying in wideband cognitive radar (WCR), the TRS information of WCR should be recursively updated by the receiver on the fly. Therefore, in WCR waveform design for target detection, TRS estimation ability should also be considered to provide the prior knowledge for the optimization of the next waveform. To address this problem, a WCR waveform design method is proposed for target detection by maximizing the average signal to clutter plus noise ratio of the received echo on the premise of ensuring the TRS estimation precision. By constraining the estimation performance, a convex cost function is established and the optimal solution can be obtained by the existing convex programming algorithm. Furthermore, for the convenience of waveform optimization in real time, a fast hierarchical scheme is also proposed with comparative performance. Numerical results show that, the proposed methods are able to improve the target detection performance under given estimation performance constraint. Manuscript

Radar Constant-Modulus Waveform Design with Prior Information of the Extended Target and Clutter

“…We have assumed that the target is static (or equivalently, that the Doppler shift has been precisely measured and compensated), which is also implied in Figure 1. The assumption of the zero-Doppler target has also been made in [8,9,10,11,12,13,14,19,22,23,24,25,26,27,29]. According to [19], if we obtain the optimal waveform with this model, improved performance will result with the optimized waveform in the moving target case as well.…”

“…Generally, radar waveform design methods can be broken into four categories: (1) information theory based design [7,8,9,10,11,12,13,14]; (2) ambiguity-function based design [15,16,17]; (3) detection-probability based design [18,19,20]; and (4) signal-to-clutter-plus-noise ratio (SCNR) based design [21,22,23,24,25,26,27]. Information theoretic methods were inspired by the very essence of radar—acquiring target related information [7].…”

“…However, much existing work [8,10,11,12,13,14,16,17,18,19,20,22,23,24,25,26,27] is based on the assumption that radar transmitted signals can be modulus-arbitrary—something which is still difficult to implement in present radar systems—limited by the linear range of the radio frequency (RF) power amplifier and the capabilities of present RF antennas [5,21,28,29]. Accordingly, the design of radar waveform with limited dynamic range was considered in [5,28], and constant-modulus waveform design was discussed in [21,29].…”

Cognitive Waveform Design for Radar-Communication Transceiver Networks

“…And the transmitted waveform is optimized in order to improve the estimation performances [33]. However, the direct optimization problem of waveform design in the temporal correlated cognitive radar system (CRS) is nonconvex and cannot be solved efficiently.…”

Statistical Model of Centimeter Range Signals That Have Passed The Surface and Space Propagation Path

“…It is known that the output signals of antennas on the tropospheric and space propagation paths of radio waves can be expressed as the sum of the radio emission source signal and the scattered component due to medium inhomogeneities [1][2][3][4][5]. While scattering of radio waves by small-scale inhomogeneities in the troposphere, the scattered component is described by a stationary normal random process, when the observation interval of the signal does not exceed several seconds and the transmitting points are fixed [3,5].…”