Differential correction method applied to measurement of the FAST reflector

• 来源期刊: 天文和天体物理学研究
• 年，卷（期）: 2016,（8）
• 页码范围: 25-32
• 页数: 8页
• 语种: 英文
• DOI: 10.1088/1674-4527/16/8/121

摘要

The Five-hundred-meter Aperture Spherical radio Telescope (FAST) adopts an active deformable main reflector which is composed of 4450 triangular panels.During an observation,the illuminated area of the reflector is deformed into a 300-m diameter paraboloid and directed toward a source.To achieve accurate control of the reflector shape,positions of 2226 nodes distributed around the entire reflector must be measured with sufficient precision within a limited time,which is a challenging task because of the large scale.Measurement of the FAST reflector makes use of stations and node targets.However,in this case the effect of the atmosphere on measurement accuracy is a significant issue.This paper investigates a differential correction method for total stations measurement of the FAST reflector.A multi-benchmark differential correction method,including a scheme for benchmark selection and weight assignment,is proposed.Onsite evaluation experiments show there is an improvement of 70％-80％ in measurement accuracy compared with the uncorrected measurement,verifying the effectiveness of the proposed method.