先进多孔径视宁度廓线仪数值模拟研究

先进多孔径视宁度廓线仪(A-MASP)由两台小望远镜组成,通过望远镜观测太阳表面的米粒结构进行日间湍流廓线测量.两台望远镜之间的相对指向误差可以通过改进的湍流廓线测量公式消除.数值仿真研究表明,使用消除抖动的湍流廓线计算公式后,发现A-MASP对地表附近的湍流不敏感.当两台望远镜距离为0.4 m时,无法测量400 m以下的湍流.在A-MASP中,采样高度的不均匀分布会造成测量结果的失真,可通过等效采样高度的计算方法,对该失真进行修正.通过100层相位屏对大气湍流的仿真,结果表明当望远镜距离不同时,湍流廓线测量的结果各有侧重.当距离较近时(0.4 m),A-MASP对0.4–5 km的湍流廓线测量精度较高.当距离为1.2 m和2.0 m时,对5 km以上的湍流廓线测量较准确.

Numerical Simulation Research of Advanced Multiple Aperture Seeing Profiler

The Advanced Multiple Aperture Seeing Profiler (A-MASP) consists of two small telescopes, and it could measure the daytime turbulence profile by observing the granulation of the solar surface. The advanced formula used to measure the turbulence profile could eliminate the relative pointing error between the two telescopes. The method of numerical simulation is used to study the detection performance of this instrument. The A-MASP is insensitive to turbulence near the earth''s surface after the calculation formula of turbulence profile for eliminating jitter is used. When the distance of the two telescopes is 0.4meter, turbulence below 400meters could not be measured. In A-MASP, the sample height is not uniform, which will cause the distortion of the measurement result. Thus a method for calculating the equivalent sampling height is proposed, which could correct this distortion effectively. 100 layers of phase screens were used to simulate the atmospheric turbulence profile. The results show that when the distance of the telescopes is different, the results of turbulent profile measurements have their own focuses. When the distance is relatively close (0.4m), A-MASP has a high accuracy for measuring the turbulence profile from 0.4km to 5km. When the distance is 1.2meters and 2.0meters, the measurement of turbulence profile above 5km is more accurate. Turbulent profiles could be obtained at different heights by changing the distance of the telescopes.