丽江高美古的二期选址——3#点和6#点的视宁度对比观测

介绍了丽江高美古二期选址在踏勘和筛选工作的基础上 ,对 3 # 点和6# 点的视宁度进行了对比观测。通过对 1 999年 2月 6日～ 1 999年 1 2月 3 1日 2个点共 4 756组同时段观测数据的统计和处理得到 :3 # 点的视宁度平均值为 1 1 .2 62 3cm ,6# 点的视宁度平均值为 1 1 .5952cm。经F分布检验和t分布检验假设成立 ,作出 3 # 点和 6# 点的视宁度无显著性差异的推断 ,与初期用衍射环观测视宁度的结果一致 ,进一步说明了高美古整个山头的视宁度都是优良的

The Second Term Site Survey in Gaomeigu Station,Lijiang -Comparative Observation of the Seeing Between No.3 and No.6 Hill

Based on the experience of many site surveys in the world,the seeing shows difference at various hills in the same site.In order to check the difference of the seeing at various hills in Gaomeigu site,we firstly observed at ten hills using the method of eye diffraction ring observation,then we selected No.3 and No.6 hills to do the comparative observation of the seeing using two of the three-subaperture DIMMs(Differential Image Motion Monitor) at the second term site survey.The two DIMM equipments have the same technical parameters and are installed on two 35cm telescopes respectively.Based on the statistical results of 4756 sets of observed data from 6 Feb.1999 to 31 Dec.1999,we have found the following results:(1) The average seeingis are 11.2623cm for No.3 and 11.5952cm for No.6. It is shown that two hills have no obvious difference for the seeing.This result is consistent with the previous eye diffraction ring observation.(2) There are 16 days in which the seeing in No.3 hill is better than one in No.6 (about 43.24%),while there are 21 days in which the seeing in No.6 hill is better than one in No.3 (about 56.76%).It shows that the seeing in No.6 is slightly better than one in No.3. (3) The curves of seeing variation with time were obtained in two days of 29 March and 16 May in 1999.It shows that the curves have a similar shape.(4) The curves with obviously different shapes in two hills were observed on 11 April in 1999.This situation could be caused by the local wind velocities and directions.In summary,the whole mountain in the Gaomeigu site has good seeing.No obvious seeing difference has been observed at the various hills in the Gaomeigu site.