射电天文研究组知识库

30～300 MHz的甚高频（Very High Frequency, VHF）频段是重要的射电天文波段，该频段观测采用天线阵组阵方式。稀布阵列具有空间分辨率高、副瓣电平低以及造价低等优点，进一步的天线阵综合加权可以对天线阵主瓣波束进行有效赋形，对最大旁瓣副瓣（Maximum Side Lobe）电平和远区栅瓣（Far Side Lobe）电平进行抑制。首先回顾了射电天文甚高频稀布阵列研究发展和现状，以及将会遇到的难点，提出了首先优化最优稀布天线阵元排布，进一步提出融合高性能计算平台+FPGA SOPC的稀布甚高频射电天文阵列信号处理结构体系，在图形处理器（Graphics Processing Unit, GPU）或者云计算平台上完成对天线阵各阵元频点加权参数的计算，然后通过高速总线将计算参数下发到前端的信号处理板中，通过FPGA SOPC完成对加权参数的配发。进一步分析计算了多波束情况下的数据率，可以实现实时的参数配置。本文成果为下一步大规模甚高频天线阵架设提供了技术依据。 

VHF ( Very High Frequency) band is one of important observation bands in Radio astronomy field. In this band, we usually use the array to form phased array telescope. In another hand, sparse array has more space resolution and lower side lobe level comparing with the regular array. Furthermore, based on array integrated optimization algorithms, we can effectively form the main beam and reject the Maximum side lobe levels and far side lobe levels. In this paper, at first, we review the development and research status of VHF sparse array in radio astronomy filed and analyze difficulties. The second, we promote a pipeline for sparse array building. The first step is constructing the optical elements configuration based on some optimization algorithms. And then, we promote a signal processing structure based on high performance computing severs and FPGA ( Field Programmable Gate Array) SOPC ( System On Programmable Chip) platform. In this platform, taking advantage of strong computing capability, in the GPU embedded in severs can compute the weighting parameters of different elements and different frequency channels. And then, transmitting these parameters through the high-speed bus and delivery them to each element in FPGA SOPC. We also analyze the data rate with multi-beams that can transmit the weighting parameters in real-time. This work can provide a technical base for future large-scale VHF array building.