射电望远镜结构技术发展综述

Review of the technical development of the structures of radio telescopes

综述天文学研究极致追求下单口径射电望远镜天线结构技术发展历史.更大的口径、更高的精度、更大的带宽,是射电望远镜一直以来的追求.早期大型射电望远镜受制于重力、温度、风等自然因素对望远镜的影响和当时的技术水平,只能在较低的工作频段进行观测.自Von Hoerner提出保型设计,射电望远镜在结构设计上突破了重力极限,在与以前望远镜同等条件下能实现更大口径和更高精度,这使得射电观测波段往更短的方向扩展.随着天文科学面向更短波段的毫米波和亚毫米波观测,仅通过结构保型设计的望远镜已无法满足需求,天线保护罩、主动面控制等手段应运而生.当前大型亚毫米波望远镜已成为国际天文界的迫切需求,即使上述手段发挥到了极限也无法达到其指标要求,因此必须在方法与技术上进行大的革新.

The technical innovations of the structures of radio telescopes for the unending pursuit of astronomy was summarized.The target of the radio telescopes is always to pursuit larger aperture,higher precision and wider bandwidth.However,the performance of the telescopes was inevitably affected by gravity,temperature,surrounding temperature and so on.The early radio telescopes,constrained by the technology as well as environmental conditions,could only operate at very low frequencies.The limitations of gravity on telescope structure were broken through by the homology design theory,proposed by Von Hoerner.The theory enabled engineers to build the telescopes with larger aperture and higher accuracy in the same conditions.Thus,the operating wavelength of the radio telescopes could be shorter.Since the astronomers turned interest to the science goals of millimeter and submillimeter waves,the precision requirement of the telescopes,which was very high,could not be guaranteed by only the homology design theory.The antenna dome,active surface control and other ways had been used to guarantee the performance.Today,the urgent requirements from the international astronomical community spawns many plans of the single dish large sub-millimeter telescopes.The existing means can′t make the large sub-millimeter telescopes meet the targets even if all the means are pushed to their limits.Thus,it is urgently necessary to make the new breakthroughs in methods and techniques.