Abstract
To improve the efficiencies of the traditional spectrum reconstruction techniques, an improved spectrum reconstruction technique (ISRT) based on chirp rate modulation (CRM) is proposed. With the help of a CRM operation, a reconstructed wideband signal with a narrow pulse width can be obtained. Compared with the traditional time domain spectrum reconstruction technique (TSRT), ISRT is less time-consuming since much less samples are needed. Compared with the traditional frequency domain spectrum reconstruction technique (FSRT), the reconstructed signal is a chirp signal, which has no limitation on the subsequent imaging algorithm. What is more, processing steps of ISRT are optimized, and the computational burden is less than that of TSRT and FSRT. Both simulation results and real data processing have verified the validity of ISRT.
创新点
本文提出了一种改进的频谱重建方法。此方法仅在频域就可以对各子带信号进行精确的频谱重建, 这大大降低了频谱重建的运算量。同时, 此方法通过对匹配滤波后的子带信号进行调频率调制来降低频谱重建后宽带信号的点数, 这又大大提高了此方法的效率。因此, 相对于传统的时域和频域频谱重建方法, 此方法具有更高的效率, 并且其重建得到的宽带chirp信号具有较少的点数, 这有利于降低后续SAR成像处理的运算量。
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Gao, W., Ding, Z., Zhu, D. et al. Improved spectrum reconstruction technique based on chirp rate modulation in stepped-frequency SAR. Sci. China Inf. Sci. 58, 1–11 (2015). https://doi.org/10.1007/s11432-015-5329-3
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DOI: https://doi.org/10.1007/s11432-015-5329-3
Keywords
- chirp rate modulation (CRM)
- spectral efficiency
- improved spectrum reconstruction technique (ISRT)
- spectrum reconstruction
- stepped-frequency
- SAR