射电天文研究组知识库

目前，压缩感知的研究热点主要集中在重构算法改进方面，即如何降低重构误差和重构时间，且均在实际应用允许的范围内，而对于信号频域分析中提高频谱分辨率技术的关注较少。利用调制宽带转换器（Modulated Wideband Converter, MWC）对稀疏信号进行采样，采用正交匹配追踪（Orthogonal Match Pursuit, OMP）算法重构输入信号，通过延长时域采样时长，实现单个通道低速采样的同时提高频谱分辨率。对低频射电天文信号进行仿真实验，结果表明，在单个通道采样速率相同时，时域采样样本数由459增加至999,频谱分辨率由0.435 7 MHz提高至0.200 2 MHz,但采样系统的总采样样本数仅由102增加至222。本文的研究为射电天文信号等高频窄带信号处理提供了良好的借鉴。

At present, the research on compressed sensing mainly focuses on reducing the reconstruction error and the reconstruction time by improving the reconstruction algorithm. The reconstruction error and reconstruction time lie in the practically allowed range. Researchers usually pay less attention to improving techniques of spectral resolution in the frequency domain analysis. In this paper, we use the modulated wideband converter (MWC) to sample the sparse signals, and employ the orthogonal matching pursuit (OMP) algorithm to reconstruct the input signals. By extending the sampling time, low sampling rate in one channel is realized, and the spectral resolution is improved. The experimental results of low⁃frequency radio astronomical signals show that the spectral resolution increases from 0. 435 7 MHz to 0. 200 2 MHz when the number of samples in time domain increases from 459 to 999 with the same sampling rate for all channels. Meanwhile, the total sample number of the system increases from 102 to 222. Our work provides a good reference for processing the narrowband high⁃frequency signal, such as radio astronomical signals.