Costas DFC-Based Random Stepped Wideband Waveform for Interference Countermeasure in SAR Imagery

Abstract

Interference in SAR imagery will induce false targets or form a mask in specific areas to prevent accurate scene assessment. Traditional anti-jamming methods based on waveform agility require a trade-off between anti-jamming performance and imaging quality in waveform design. In this paper, we proposed a SAR ECCM scheme including a Costas DFC-based random stepped wideband waveform and corresponding imaging processing method. The waveform exhibits high flexibility against forwarding interference due to the decomposition of a wideband signal into multiple pulses with different Costas discrete frequency encoding, carrier frequency and phase modulation. Furthermore, the combination of FCDC and the imaging processing successfully overcomes the Doppler sensitivity of the proposed waveform. Extensive simulations confirmed the superiority of this waveform and processing method under different interference strategies.

Integrating Agile Waveforms With DBF for HRWS SAR Imagery and Adaptive Jamming Suppression

“…The false target will no longer follow the dependency of the angle of arrival (AoA) and the delay time from the real scatter, so the elevation DBF can realize the jammer suppression by spatial filtering based on the precise estimation of the jammer location. Moreover, the Doppler sensitivity of the SSC-DFC waveform can counter the frequency-shift interference [28].…”

“…The ambiguity suppression simulations are performed on the point target and the line target, where the length of the line target is comparable to the pulse width. The Costas-DFC waveform [28] and the cross-correlation optimized NLFM waveform [13] have been applied as comparisons. The point target is placed at the scene center.…”