上海65米射电望远镜副面位置建模及性能测试

发布时间：2018-03-26 04:52

本文选题：副面　切入点：位姿　出处：《上海应用技术大学》2016年硕士论文

【摘要】：大型射电望远镜在观测过程中,随着俯仰角度的变化,副面支撑、背架、主反射面等都有不同程度的变形,这将导致天线效率在高低俯仰角上明显下降,上海65米射电望远镜副面系统的安装可以用来补偿副面支撑和主面的重力变形,在不同的俯仰角度上,副面位姿的调整可以提高天线的效率和指向性能。通过在X波段和Ku波段研究副面位姿变化对天线效率的影响,用射电法建立了随俯仰角度变化的副面位姿随动调整模型和副面偏移导致的指向补偿模型。用最小二乘法对全天区数据进行拟合,得出了8个天线参数的指向模型,并在实际中验证,最后建立了上海65米望远镜X波段指向模型。随机盲指误差达到12.36角秒,满足了X波段及更长波段的指向要求。采用全息法获得的口径面相位拟合了副面在X、Y、Z三个方向的偏移量,并与采用射电源幅度扫描法建立的副面偏移模型进行了比较,两者一致性较好,尤其是Z向拟合情况非常一致。此外还测试了副面随动与固定对天线效率的影响,结果表明副面随动模型可以有效改善上海65米望远镜在高低俯仰角上的效率,使得在整个俯仰角范围内,X波段的接收效率均达到60%以上。
[Abstract]:In the observation process of large radio telescope, with the change of pitch angle, the auxiliary surface support, back frame, main reflector and so on have different degrees of deformation, which will cause the antenna efficiency to decrease obviously in high and low pitch angle. The installation of the auxiliary surface system of the Shanghai 65-meter radio telescope can be used to compensate for the side support and gravity deformation of the main plane, at different pitch angles. The efficiency and directivity of the antenna can be improved by adjusting the pose of the secondary plane. The effect of the change of the position and pose on the efficiency of the antenna is studied in X-band and Ku-band. Based on the radio method, the following adjustment model of the position and pose of the auxiliary plane with the pitch angle and the direction compensation model caused by the offset of the auxiliary surface are established. The data of the whole sky area are fitted with the least square method, and the pointing model of the eight antenna parameters is obtained. Finally, the X-band pointing model of Shanghai 65m telescope is established. The random blind pointing error is 12.36 angle seconds. The aperture plane phase position obtained by holographic method is used to fit the offset of the secondary plane in three directions, and compared with the offset model established by the radio power source amplitude scanning method. In particular, the Z-direction fitting is very consistent. In addition, the effect of the auxiliary surface tracking and fixing on the antenna efficiency is also tested. The results show that the auxiliary surface tracking model can effectively improve the efficiency of the Shanghai 65m telescope in the high and low pitch angle, and the receiving efficiency of X band is over 60% in the whole range of pitch angle.
【学位授予单位】：上海应用技术大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P111.44

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