自主创新高性能天文数字后端平台

Digital backend is one of the most important parts of telescope construction, and directly related to the observing performance. With the fast improvement of the sensitivity of single dish and array telescope, e.g., the Five-Hundred Aperture Spherical Radio Telescope (FAST) and TianLai etc., the current digital backend platform would not be able to meet the high sampling speed, resolution and high computing ability needs. By studying the hardware-reconfigurable platform with digitization, computing and data transfer, utilizing the most advanced FPGA and highest-resolution Analog to Digital (AD) chips that commercially-available, we will construct a high performance astronomical digital backend platform and corresponding drivers and typical astronomy DSP modules. Taking the advantage of the reconfigurable architecture and world-class performance, this platform will be able to not only meet either single dish or array telescope under construct or upgrade in China, but also use by astronomer in the world. We will have complete intellectual property from design to implementation.

数字后端是天文望远镜的核心组成部分，它直接影响着系统的观测效果。随着我国FAST、“天籁”等新建大型单天线及阵列天文望远镜性能指标的提升，使用已有数字后端平台已经无法满足系统对超高采样频率、分辨率以及超强处理能力的需求。本项目通过对硬件可配置的先进采集—处理—传输架构进行研究，采用最新型FPGA以及业界精度最高的高速AD采样芯片，研制一套高性能自主创新天文数字后端平台，并配套相应的驱动与天文常用信号处理模块。由于采用了硬件可配置设计，该平台在性能上可以满足我国在建或升级中的单天线及阵列天文望远镜的不同需求。凭借世界先进的性能指标和灵活性，该系统还可以推广给国外用户。通过本项目，我们可以在设计，生成和使用各阶段，实现数字后端平台自主可控和自主产权。

本项目自主研制的基于FPGA的数字后端平台已完成全面的测试并已投入运行，与其他望远镜数字后端相比，在谱线观测和脉冲星观测方面性能指标均高于现有常用其他数字后端设备。高带宽数据综合变频-并行分路模块可分别对实时相干脉冲星搜索通道、非相干脉冲星搜索通道与原始采集数据通道进行综合数字下变频与数字并行分路，以及在数字部分进行同步时标标注，解决了数据高精度同步问题。其中高速数据交织采集模块通过使用同源反相时钟交织采样技术，使12bit分辨率ADC的采样率达到6.4GSPS，可以完全覆盖FAST（Five-hundred-meter Aperture Spherical Telescope，简称FAST） 3GHZ的频率覆盖范围，产品已被国外望远镜采用。