RADIANT - Radio Astronomy with Low-Complexity Sensors

一台新的低频射电望远镜即将投入使用，它将挑战我们对宇宙和物理基本定律的看法。平方公里阵列（SKA-low）的低频接收器拥有超过10万个天线，形成了射电天文学的一个技术里程碑，与其前身低频阵列（LOFAR）一起拥有大约5000个天线，构成了向全电望远镜系统设计范式转变的完成。在超级计算机的帮助下，SKA-low和LOFAR不再使用几个大型抛物面天线，而是将来自大量小型传感器的信号结合起来，通过智能数字算法合成巨大的低频射电望远镜。虽然这使天文学家能够以无与伦比的灵敏度和速度进行调查，但在低频射电天文学中实现的大规模数字传感构成了一个工程挑战。由于传感器数量庞大，SKA-low产生的数据比全球互联网还要多，需要大量的光纤、超大内存和高性能处理单元。虽然在过去的几十年里，关于数字传输、存储和计算的技术能力呈指数级增长，但与模拟无线电设备相关的进步是温和的。因此，目前无线电传感器的硬件成本和功耗是建造未来由数百万天线组成的望远镜的主要障碍。该项目研究了一种可能改变游戏规则的方法。通过允许高度非线性行为，无线电传感器的模拟复杂性降低到最小。创新的硬件感知统计信号处理方法补偿了数字领域的不良影响，优化的系统设计与最大数量的传感器确保了超高的性能。联合世界一流的射电天文系统工程师和阵列信号处理以及硬件感知统计分析方面的领先科学家进行初步研究，研究工作旨在：1)定量了解具有大量低复杂性传感器的射电望远镜的潜力；II)推导所需的高性能信号处理和数据压缩算法；III)用真实的射电望远镜数据集提供概念验证；4)规划用高性能低复杂度射电望远镜样机进行验证。

A new low-frequency radio telescope is just about to start operation and challenge our perspective on the universe and the fundamental laws of physics. With more than 100,000 antennas, the low- frequency receiver of the Square Kilometre Array (SKA-low) forms a technology milestone in radio astronomy and, together with its predecessor Low Frequency Array (LOFAR) featuring approximately 5,000 antennas, constitutes the completion of a paradigm shift towards an all-electric telescope system design. Instead of using a few large parabolic antennas, with the help of supercomputers the SKA-low and LOFAR combine the signals from a massive number of small sensors and synthesize giant low-frequency radio telescopes by smart digital algorithms.While this allows astronomers to perform surveys at unparalleled sensitivity and speed, massive digital sensing as realized today in low-frequency radio astronomy forms an engineering challenge. Due to the enormous number of sensors, the SKA-low produces more data than the worldwide internet, requiring huge quantities of optical fiber, ultra-large memory, and high-performance processing units. While the technological capabilities regarding digital transmission, storage, and computation have exponentially increased during the last decades, the advances associated with analog radio equipment were moderate. Therefore, today hardware cost and power consumption of radio sensors form the main obstacles for constructing future telescopes combining millions of antennas.The project investigates a potentially game-changing approach. The analog complexity of the radio sensors is reduced to its minimum by allowing highly nonlinear behavior. Innovative hardware-aware statistical signal processing methods compensate the undesired effects in the digital domain and an optimized system design with a maximum number of sensors ensures ultra-high performance. Uniting world-class engineers for radio astronomy systems and leading scientists in array signal processing as well as hardware-aware statistical analysis for an initial study of opportunities, the research endeavor aims at: I) quantitatively understanding the potential of radio telescopes with a large number of low-complexity sensors; II) deriving the required high-performance signal processing and data compression algorithms; III) providing proof-of-concept with real radio telescope data sets; IV) planning the verification with a high-performance low-complexity radio telescope prototype.