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A Site Survey for Large Millimeter/Submillimeter Telescope

大型毫米/亚毫米望远镜现场勘察

基本信息

批准号：
06041122
负责人：
ISHIGURO Masato
金额：
$ 5.31万
依托单位：
National Astronomical Observatory
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06041122/
关键词：
Large Millimeter and Submillimeter Array radio seeing monitor radiometer atmospheric conditions at millimeter and submillimeter wavelengths meterorological conditions opacity of atmosphere at millimeter and submillimeter wavelengths phase fluc

项目摘要

Future large radio telescopes, such as Large Millimeter and Submillimeter Array (LMSA) planed by Japan, need a construction site having the following atmospheric, meteorological, and geographical conditions to bring out the capability of the telecopes to the full extent and to get many good observational results with the telscopes : 1) low opacity (i.e. high transmission) of the atmosphere even at submillimeter wavelengths, which means a high altitude place, 2) good radio seeing to achieve 0.1-0.01 arcsec resolution, 3) less windy place as possible to achieve good pointing of antennas, 4) flat or gently sloped area of more than 2km sqaure to place and move 50 antennas.According to these conditions, the present candidates of the LMSA site are Mauna Kea in Hawaii and high plateau in northern Chile.For these two potential sites, we researched atmospheric conditions (radio transmission and radio seeing), the meteorological conditions, and the geographical conditions.In order to measure atm … More ospheric and meteorological conditions in the northern Chile, we installed two 220 GHz radiometers, two sets of radio seeing monitors and four meteorological stations to the sites with altitudes of 2400-5000m and mesured these conditions from 1995 to 1996.The results of the measurements are in the following.1) Mt.Paranal (2600m) area in the northern Chile has a good atmospheric and meteorological conditions, although the altitude is not so high (2600m) and one of good sites for millimeter-wave observations.However, the area is not good site for sub-millimeter wave observations.2) There are very dry high plateaus (with an altitude of 4000-5000m) in the northern Chile.The high plateaus have extremely good atmospheric and meteorological conditions : 50% of a year can be used for sub-millimeter observations and radio seeing is as good as typically 0.5 arcsecond.It is concluded that the atmospheric and meteorological conditions in the high plateaus are statistically better than those of Mauna Kea (altitude is 4100m) in Hawaii. Less

未来的大型射电望远镜，如日本计划建设的大型毫米波和亚毫米波阵列（large Millimeter and Submillimeter Array， LMSA），需要具备以下大气、气象和地理条件的建设场地，才能充分发挥望远镜的功能，并获得许多良好的观测结果：1)低不透明度（即高透射）的大气，即使在亚毫米波长，这意味着一个高海拔的地方，2)良好的无线电观测，达到0.1-0.01弧秒的分辨率，3)少风的地方，尽可能实现良好的天线指向，4)平坦或平缓的区域超过2公里平方放置和移动50个天线。根据这些条件，目前的候选地点是夏威夷的莫纳克亚山和智利北部的高原。针对这两个潜在站点，我们研究了大气条件（无线电传输和无线电观测）、气象条件和地理条件。1995年至1996年，我们在智利北部海拔2400-5000米的地区安装了2台220 GHz辐射计、2套无线电观测监测器和4个气象站，对智利北部的大气和气象条件进行了测量。测量结果如下。1)智利北部帕拉纳尔山（2600m）地区虽然海拔不高（2600m），但具有良好的大气和气象条件，是毫米波观测的良好地点之一。然而，该地区并不是亚毫米波观测的好地点。2)智利北部有非常干燥的高原（海拔4000-5000米）。高原有极好的大气和气象条件：一年有50%的时间可用于亚毫米观测，无线电观测通常可达0.5角秒。结果表明，高原的大气和气象条件在统计上优于夏威夷的莫纳克亚山（海拔4100m）。少