A Fast Feed Switching Method for Multi-band Radio Telescope Based on Movable Subsurface

Abstract

The invention relates to a multi-band radio telescope rapid feed source switching method based on a movable minor face. The method is characterized in that a six-rod adjusting mechanism and a rotation mechanism are adopted to together drive the minor face to move, rapid feed switching and precise focusing of a radio telescope are realized, signals are reflected to the minor face from a main face and are then converged to a focal point of the minor face after the reflection of the minor face, wherein the focal point of the minor face is the position of a receiver and feed sources. An antenna controls a computer to send an instruction for controlling the minor face rotation mechanism to drive a minor face electric shaft to rotate, and the focal point of the minor face is enabled to be superposed with the wave band feed source to be used. According to the antenna efficiency, the focusing condition is judged, a minor adjusting instruction is sent in an offset focus case, the minor face six-rod adjusting mechanism and the minor face rotation mechanism are controlled to together form a minor face movement adjusting mechanism, and the precise six-freedom-degree adjustment and focusing of the minor face are realized. The method has the advantages that the precision is high, the stability is good, the feed switching efficiency is substantially improved, and the method is especially important for the feed switching and focusing of short centimeter wave and event millimeter wave receivers high in matching precision.

Description

technical field [0001] The invention relates to a method for quickly switching feed sources of a multi-band radio telescope based on a movable secondary surface, using a six-bar mechanism and a rotating mechanism to jointly drive the secondary surface to move, and a method for fast feed switching and precise focusing of the radio telescope, which is specially used for radio telescopes Feedback and focusing of the receiver. Background technique [0002] Radio astronomy is an important research field in astronomy. Radio telescopes are basic equipment used in radio astronomy to observe and study electromagnetic waves radiated from celestial bodies. The Nanshan 25-meter radio telescope system of the Xinjiang Astronomical Observatory of the Chinese Academy of Sciences is a modified Cassegrain antenna system. The radio signal is reflected from the main panel of the antenna to the sub-surface, and then reflected by the sub-surface to the receiver feed source, and then collected by...

AI Technical Summary

Problems solved by technology

If the accuracy of the feed-forward system of the radio telescope is not high, it will cause a loss of antenna efficiency due to defocusing, thereby reducing the quality of the received signal

[0005] The original 25-meter radio telescope of the Xinjiang Astronomical Observatory of the Chinese Academy of Sciences has been built for more than 20 years. The equipment has exceeded the service life, the antenna structure system has aged, and the reliability of the antenna system has declined.

At the same time, some performance indicators of the antenna can no longer meet the requirements of current and future astronomical observations and scientific research.

In particular, the original linear guide rail feed replacement method is inefficient (it takes 20 minutes to replace a feed source), and the focusing accuracy after feed replacement is low

As stated in the papers "Software and Hardware Implementation of Fuzzy Control Strategy for Automatic Feedback System of 25m Radio Telescope" and "Automatic Feedback Control System for Laser Positioning Based on Fuzzy PID Control", although the Xinjiang Astronomical Observatory of the Chinese Academy of The feed-forward system has undergone several upgrades, but under the premise of the linear guide rail feed-forward mode, the feed-forward efficiency is low and cannot be changed, and there has always been a situation where the phase center of the feed deviates from the focal point of the secondary reflector of the antenna. In the existing K-band Observational performance is very obvious

[0006] Chinese patent 201420602910.2, "A Feedback Way for Linear Guide Rail", states that the slider of the linear guide rail feedforward system suffers from small friction during movement, and the service life of the whole mechanism is longer, and the equipment is within its design life It can guarantee the accuracy and does not need to add lubricating oil regularly. It is easy to maintain, it will not cause inconsistencies in each set of equipment due to processing errors, and it is more convenient to debug.

[0007] The antenna sub-surface adjustment mechanism described in Chinese patent 201120391681.0 "Large Antenna Sub-surface Adjustment Mechanism" fixes the sub-surface through the middle bracket and the top bracket. When the sub-surface needs to be adjusted, loosen the bolts in the left and right or front and rear directions Finally, adjust the position of the auxiliary surface. At this time, the weight of the entire auxiliary surface is borne by the top bracket of the middle support machine, but the entire adjustment process requires manual operation by personnel, which has poor repeatability, low efficiency, and accuracy cannot be guaranteed.

Images