WBI Suppression for SAR Using Iterative Adaptive Method

Abstract

Under the condition of wideband interference (WBI) with the characteristics of good time-frequency concentration but high nonstationarity, the limited time width of the window function in short-time Fourier transform (STFT) causes limited instantaneous frequency resolution and leads to great performance degradation of the conventional WBI suppression algorithm based on time-frequency filtering (TFF) method. A novel WBI suppression method using iterative adaptive approach (IAA) and orthogonal subspace projection (OSP) method is proposed for synthetic aperture radar (SAR). Dispensing with parametric search and model order estimation, the proposed method improves the instantaneous frequency resolution in STFT by means of the IAA method and filters the WBI based on the OSP method, meanwhile, obtains time-frequency distribution (TFD) with 2-D high resolution and no cross-terms. Both the simulation and experimental results are provided to illustrate the performance of the proposed method.Index Terms-Iterative adaptive approach (IAA), orthogonal subspace projection (OSP), synthetic aperture radar (SAR), wideband interference (WBI) suppression.

Mitigation of Radio Frequency Interference in Synthetic Aperture Radar Data: Current Status and Future Trends

“…In [32] and [60], time-frequency reconstruction and the mask technique are proposed to filter the RFI. To achieve super resolution of the time-frequency representation and reduce the signal loss, iterative adaptive approach (IAA) [61,62] features the adaptive RFI estimation and is believed to be more compatible with the time-variant RFI. Su et al proposed using delay-Doppler iterative decomposition algorithm on the Wigner distribution [63].…”

Wideband Noise Interference Suppression for Sparsity-Based SAR Imaging Based on Dechirping and Double Subspace Extraction

“…Parametric methods such as high-order ambiguity function (HAF) [13,14], fractional Fourier transform (FrFT) [15], empirical mode decomposition (EMD) [16], and time-frequency analysis (TFA) [17] are based on polynomial signal modeling, the performances of which are heavily dependent on the order of the model. Non-parametric methods such as the time-frequency filtering (TFF) [18,19] and the iteration-adaptive approach (IAA) [20] separate the signal and the interference by utilizing their respective concentrations in the time-frequency domain, where the TFF method simplifies the WBI to a series of instantaneous NBIs by short time Fourier transform (STFT). Sparse recovery, as a kind of semi-parametric method, is state-of-the-art, especially in terms of reducing signal distortion.…”

Multiclass Radio Frequency Interference Detection and Suppression for SAR Based on the Single Shot MultiBox Detector

“…With their ability to obtain high-resolution images under all time and weather conditions, synthetic aperture radar (SAR) systems are proven to be very useful methods for earth resource surveys and military reconnaissance. Apart from the target signal, signals received by the SAR system may also have interference from communication devices, television networks, and other radar systems [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. These interference signals are collectively referred to as radio frequency interference (RFI).…”

“…These interference signals are collectively referred to as radio frequency interference (RFI). On the one hand, the energy of RFI is much greater than the energy of the target signal, which may result in the quality of a SAR image being significantly degraded [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. On the other hand, there are diverse forms of RFI due to their different sources [ 1 , 2 , 3 ].…”