论文标题
H-fista：用于相位检索的层次结构算法，并应用于脉冲星动态光谱
H-FISTA: A hierarchical algorithm for phase retrieval with application to pulsar dynamic spectra
论文作者
论文摘要
脉冲星动态频谱是星际介质的内联数字全息图。它编码有关信号从源到望远镜传播的传播路径的信息。为了解码全息图，有必要从强度测量值中“检索”波场的相位，该强度测量直接通过对模型施加其他约束来直接衡量场模量。我们提出了一种在PULSAR光谱学背景下进行相检索的新方法。我们的方法利用快速的迭代收缩阈值算法（FISTA）以分层方法逐渐增加的深度以层次结构方法获得波场的稀疏模型。一旦到达噪声分布的尾巴，层次结构将以最终的未注册优化终止。结果是复杂波场的完全致密模型，该模型允许通过适当的平均发现微弱的信号。我们说明了方法在合成测试用例和实际数据上的性能。我们称为H-Fista的算法以Python编程语言实现，并可以免费使用。
A pulsar dynamic spectrum is an inline digital hologram of the interstellar medium; it encodes information on the propagation paths by which signals have travelled from source to telescope. To decode the hologram it is necessary to "retrieve" the phases of the wavefield from intensity measurements, which directly gauge only the field modulus, by imposing additional constraints on the model. We present a new method for phase retrieval in the context of pulsar spectroscopy. Our method makes use of the Fast Iterative Shrinkage Thresholding Algorithm (FISTA) to obtain sparse models of the wavefield in a hierarchical approach with progressively increasing depth. Once the tail of the noise distribution is reached the hierarchy terminates with a final, unregularised optimisation. The result is a fully dense model of the complex wavefield that permits the discovery of faint signals by appropriate averaging. We illustrate the performance of our method on synthetic test cases and on real data. Our algorithm, which we call H-FISTA, is implemented in the Python programming language and is freely available.
