摘要
本文提出在大气Greenwood时间常数内采用同步探测技术实现钠导星聚焦非等晕性测量,开展了脉冲体制钠导星探测实验,实现了对大气平流层顶端钠导星和同路径自然星可见光波段的哈特曼点阵的同步探测,并获得钠导星回光单帧波面,从波面一致性对比、Zernike系数比较、模拟成像校正等方面对实验结果进行较全面分析.实验结果表明,在当前实验条件下,虽然脉冲钠导星的单帧哈特曼点阵的成像对比度较低,制约了波面恢复精度,但同步测量的两组波面始终能保持相似性,其Zernike系数在前36阶一致性较好,模拟结果表明钠导星探测波面有助于实现对自然星成像的有效校正,扣除波面恢复误差后的聚焦非等晕性方差小于0.1rad2,十分接近理论结果.
No reports of measuring the focusing anisoplanatism of laser guide star were mentioned before because the guide star instantaneous wavefront measurement technique by using sodium is not mature. As directly verifying the confi-dence of artificial sodium guide star which takes the place of the natural star to become the reference of atmosphere adaptive optic correction, in this paper a new method is put forward that the focusing anisoplanatic error of sodium guide star can be measured via synchronous pulse detection if the atmosphere Greenwood time is constant. Results of correlation analysis show that it is feasible to establish an experimental system for the measurement. A high-precision wavelength and linewidth sodium guide star laser and a 1.3 m caliber telescope underly the experimental system for the technology research on the focus anisoplanatism. Experiment of detecting sodium guide star has been carried out. And synchronous detection about the returning light matrix of visible light of sodium and the natural star is achieved when both are in a coincident imaging path. In the experiment, the recovered single frame wavefront of sodium guide star is acquired, and experimental data analysis is carried out in several aspects： contrasting the coherence of the two types of wavefront images, comparing the Zernike coe？cients, and simulating the imaging calibration. Results show that the imaging contrast in the light matrix of the plused sodium guide star is poor because of the limited experimental condition so that the precision of the recovered wavefront is restricted, but the two groups of wavefronts the sodium guide star wavefront and the natural star wavefront always keep nice comparability, which we can see from the recoverd synchronous wavefront images. And the Zernike coe？cients of both are close in the first 36 orders, which we deduce from the Zernike anisoplanatic error curves. Simulation result shows that the acquired sodium wavefront data would con-tribute to calibrate the far-field images of natur
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2015年第13期174-181,共8页
Acta Physica Sinica
基金
国家高技术研究发展计划(批准号:2013AAXXX1040)资助的课题~~
关键词
同步探测
钠导星
聚焦非等晕性
波面方差
synchronous detection
sodium guide star
focusing anisoplanatism
wavefront
