Subjects: Astronomy >> Astrophysics submitted time 2024-01-22
Abstract： Deconvolution of radio astronomy images is a key data processing technique. Its main goal is to remove the effects introduced by the instrument from the observed sky images to recover the original sky images.However, radio interferometer arrays employ sparse interferometric arrays, whose imaging principles differfrom those of optical telescopes. If the sampling points in the UV space are not sufficiently dense, this will lead to insufficient high-resolution information during image reconstruction. Traditional radio astronomy image reconstruction algorithms fail to fundamentally solve the problem of UV space undersampling. This paper adopts the compressed sensing theoretical framework, combines prior knowledge of the sparsity of radio astronomy images, and studies a new radio astronomy image deconvolution algorithm, namely the IUWT-CS-based radio interferometric image reconstruction algorithm. This algorithm transforms the dirty image deconvolution process into a convex optimization problem to find the global minimum. To evaluate the reconstruction performance of this algorithm, we used the OSKAR radio astronomy simulation software package to simulate low SKA1 observations and performed deconvolution processing on the extended radio sources obtained. Experimental results show that, compared with the HOGBOM-CLEAN, MS-CLEAN,and IUWT-FISTA methods, the IUWT-CS method significantly improves the reconstruction quality of radio images and achieves finer denoising and restoration effects.
Peer Review Status:
Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2017-09-26 Cooperative journals: 《天文研究与技术》
Abstract：随着数据记录速率的提高以及对数据准确性的要求，老的采集系统已经不能满足新的要求，迫切要求采用新的终端和技术。Mark6是麻省理工学院研制的最新的记录终端，已经用于主要的天文机构，比如JIVE, KASI, Max-Planck-Institute等。首先介绍了VLBI数据记录终端的现状，给出了上海天文台对Mark6软硬件的调试与配置;然后介绍了使用Mark6与CDAS2互连进行数据记录的测试及分析;最后对Mark6系统的应用及相关软件的后续研发进行了简洁阐述。可为后续终端采集系统的安装、配置及升级提供指导及参考。
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