摘要
提出一种新颖的大球面射电望远镜的设计方案．以往球面射电望远镜的设计方案是利用各种复杂馈源系统，如Ａｒｅｃｉｂｏ三反射面系统来克服球差，而我们拟实时地改变被馈源照明的部分球反射面的形状以最大限度地拟合旋转抛物面，从而用传统的抛物面馈源照明来实现宽带与偏振观测．此设计有天空覆盖范围大及可实现独立多瓣观测等优点．文中还对５００ｍ口径的球面射电望远镜（曲率半径３００ｍ）以及３００ｍ可用口径的具体实例提出了实施方案．
novel design for giant spherical radio telescope is suggested. Instead of using a complex feed system for the correction of the aberration (such as Arecibo Gregorian subreflector), an active main reflector is proposed. The part of main reflector which is illuminated by the feed is continually adjusted to fit the paraboloid of revolution in realtime when tracking the radio source. Thus a simple feed for a parabolic antenna can be used for this system. This concept is applied in the design of a large spherical radio telescope having a total reflecting spherical surface 500m in diameter (radius of curvature 300m), while an usable aperture 300m. The main advantages in this design are large zenithangle coverage, a simple feeding system (so that it is easy to achieve broad bandwidth and full polarization) and low cost.
关键词
球面射电望远镜
旋转抛物面天线
主动主反射面
spherical radio telescope—active main reflector—paraboloid radio telescope
