Research for Diffraction Limited Imaging with Large Optical Telescope

大型光学望远镜衍射极限成像研究

基本信息

批准号：
63460009
负责人：
ISHIGURO Masato
金额：
$ 4.67万
依托单位：
National Astronomical Observatory
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1990
项目状态：
已结题

项目摘要

In this research, we have developed an aperture synthesis method with a non-redundant aperture mask (NRM) to obtain diffraction limited images with a large optical telescope. In 1988, we constructed a data acquisition system, investigated the design method of 2-dimensional NRM, and conducted a fundamental optical simulation. In 1989, based on these results and using the data using the data acquisition system, we observed single stars and binaries with the 91 cm telescope at Dodaira Astronomical Observatory, National Astronomical Observatory (NAO). From these observations, we found that the atmospheric fluctuations are very severe in Japan and an image stabilizing system must be required. Thus, in 1990, we developed an aperture masking system with an image stabilizing function. Using the system for NRM observations with the 188 cm telescope at Okayama Astrophysical Observatory, NAO, we confirmed good response of the imaging stabilizing function and obtained a lot of fundamental data for diffraction limited imaging. From our investigations, we obtained following results :1. The radius of the coherence patch is less than 3 cm in Japan. Since the number of sub-apertures of NRM is small, total aperture area of NRM of which sub-aperture radius is equal to that of coherence patch is very small Therefore, it is required to use the mask with small redundancy for weak objects.2. At longer baselines, visibility amplitude decreases severely, because the delay difference between sub-apertures is large. Some portion of this effect can be canceled out by an image stabilizing system. In the case of bad seeing, however, it is desired to use a simple adaptive optics.

在这项研究中，我们开发了一种采用非冗余孔径掩模（NRM）的孔径合成方法，以利用大型光学望远镜获得衍射极限图像。 1988年，我们构建了数据采集系统，研究了二维NRM的设计方法，并进行了基础光学模拟。 1989年，基于这些结果，利用数据采集系统的数据，我们在国家天文台（NAO）土平天文台的91厘米望远镜上观测了单星和双星。通过这些观察，我们发现日本的大气波动非常严重，必须需要图像稳定系统。因此，我们在1990年开发了具有图像稳定功能的孔径掩模系统。利用该系统与日本国家天文台冈山天体物理观测站188 cm望远镜进行NRM观测，证实了成像稳定功能的良好响应，并获得了大量衍射极限成像的基础数据。通过调查，我们得到以下结果： 1．在日本，相干斑块的半径小于3厘米。由于NRM的子孔径数量较少，子孔径半径等于相干斑片半径的NRM总孔径面积很小，因此对于弱物体要求使用冗余度小的掩模2。。在较长的基线下，由于子孔径之间的延迟差异很大，可见度幅度严重下降。这种效果的某些部分可以通过图像稳定系统来抵消。然而，在视力不佳的情况下，需要使用简单的自适应光学器件。