Position measurement system and position measurement method for outer shield of coronagraph

Abstract

The invention provides a position measurement system and a position measurement method for an outer shield of a coronagraph. Through configuring a laser feedback interference system, reference light and measuring light are adjusted so that the reference light and the measuring light are respectively emitted to the supporting rod and the disc surface of the outer shield, and the reference light and the measuring light are directly reflected by a matt black surface and return along original paths, thereby forming laser feedback and performing measurement. According to the length changes of the measured reference optical path and the measured optical path, displacement change and angle change of the outer shield of the coronagraph can be calculated according to the structures and parameters of the two optical paths. By means of the system and the method, the outer shield can be adjusted to an ideal central position, and furthermore the influence of outer shield position change to stray light of the coronagraph is researched when ambient temperature or vibration testing condition is changed. Through position measurement to the outer shield and quantitative analysis of the stray light, coronagraph design can be further improved and integral stray light level is reduced.

Description

technical field [0001] The invention belongs to the technical field of space optical observation, and relates to a position change measurement system and a position change measurement method for a coronagraph outer bunker. Background technique [0002] The corona is the outermost structure of the solar atmosphere, and it is also the place where many solar physical phenomena occur, such as coronal mass ejection (Coronal Mass Ejection, CME), coronal flow and early solar wind evolution, etc., which also affect the near-Earth space environment and form space disasters The main driver of sexual weather. Therefore, real-time and long-term continuous observation of the corona can carry out many studies related to the driving sources of heliospheric and magnetosphere activities, which are extremely important for in-depth understanding of scientific issues such as solar activities, as well as practical issues such as space environment monitoring and space weather forecasting. [000...

AI Technical Summary

Problems solved by technology

Therefore, the remaining diffracted light at its edge will form stray light in the coronagraph, which will become the background noise affecting the coronal observation

If the outer bunker cannot be adjusted to the ideal position, the overall stray light suppression capability of the coronagraph will be reduced, and in severe cases, the coronagraph will even be unable to work, especially for the coronagraph carried by space satellites, the on-orbit performance will be greatly reduced

(The Cor2b coronagraph carried by the STEREO satellite launched in 2006 has seriously affected the normal work of the coronagraph due to the large deviation between the outer bunker and the inner bunker)

There is no effective method for accurate measurement of the coronagraph's external bunker. The reasons are: in order to reduce stray light, the surface of the bunker is black, and it is difficult to carry out non-contact measurement through light detection; and the size of the bunker is too small to be on it. Place the target mirror for measurement; and if the probe contact measurement is used, the mass distribution of the outer shelter will be changed, and the latter two methods cannot realize the position change test and the coronagraph stray light test at the same time, so it is difficult to accurately establish Correlation between external shelter and instrument stray light

Therefore, how to conduct non-contact measurement of the external shelter, a key component that affects the stray light of the coronagraph, is a difficult problem that needs to be solved, which will affect the overall stray light suppression level of the coronagraph

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