Precise measurement of the atmospheric transparency for the cosmic ray energy calibration in the TA experiment

1.在气象学、行星科学、地球科学、环境科学、生物科学等领域，有许多实验是为了测量大气的性质，特别是大气的透明度，其目的是多方面的，有许多理论模型需要解释。大气是由一些化学成分的分子和各种气溶胶组成的，对流层中的环流对天气状况和热平衡起着非常重要的作用，在美国犹他州沙漠建立了一个大气监测系统，利用激光雷达（Light Detection And Ranging，LIDAR）系统和红外（IR）相机研究大气的特性。它最初的目的是测量宇宙射线实验的大气透明度，望远镜阵列实验，其中有许多荧光探测器。为此目的，应尽可能精确地确定大气消光系数和云量，例如spati ...更多信息 分辨率小于15m.2。所做的是，（1）LIDAR系统由激光发射器和光接收器组成，光电倍增管（PMT）安装在可操纵的基座上。激光器向大气连续发射脉冲光，接收机通过光电倍增管检测散射的微弱光。为了确定大气消光系数，从2005年7月开始，在犹他州沙漠使用激光雷达系统获得了大量的数据。截至2007财年末，有超过310，000个事件数据，在适当考虑大气压力影响后，通过所谓的斜率法和/或Klett法进行分析。在平静天气下，对于约10公里高度以上的垂直消光系数，得到了与瑞利散射计算一致的结果。在犹他州沙漠地区，一维大气密度模式在几个不确定度的精度范围内是合理假设。(2)LR现场的激光雷达仍在继续研发，预计将于2008财年安装。(3)我们还建议在几个分辨率范围内对瑞利散射（空气分子）分量和米氏散射（气溶胶）分量进行分析，并与理论预测进行比较。我们还于2008年3月在BRM站点安装了一台红外相机来测量大气中的云和/或水汽分量。少

1. There are many experiments to measure the atmospheric properties, especially its transparency, in the field of meteolology, planet science, earth science, environmental science, biological and so on. The purposes of their experiments are really manifold and there are many theoretical models to explain. The atmosphere is consist of molecules of some chemical components and various aerosol, and has very important role for the weather condition and the thermal balance due to circulation in the troposphere.An atmospheric monitoring system has installed at Utah desert in the USA, to study the properties of atmosphere using a laser LIDAR(Light Detection And Ranging) system and an infra-red(IR) camera. Its original aim is to measure the atmospheric transparency for a cosmic rays experiment, the Telescope Array Experiment, which has many fluorescent light detectors. For this aim, the atmospheric extinction coefficient and the cloudiness should be determined precisely as possible, e.g. spati … More al resolution of less than 15m.2. What have done are ;(1) The LIDAR system consisits of a laser emitter and a light receiver with a photo multiplier tube(PMT) mounting on a steerable base. The laser emits pulse lights successively into the atmosphere and the receiver detects scattered faint lights by the PMT. To determine the atmospheric extinction coefficient, a large amount of data has been acquired using LIDAR system at the Utah desert commencing from July 2005. There are over 310,000 events data at the end of FY2007 and is analyzed by means of so-called the slope method and/or the Klett's method after due consideration of atmospheric pressure effect. A consistent result with a calculation of the Rayleigh scattering is obtained for the vertical extinction coefficient above an altitude of about ten kilometres in a calm weather. It is also found that the one-dimentional atmospheric density model is reasonable assumption within the accuracy of few percent uncertainty on a limitative condition in the Utah desert.(2) The LIDAR for LR site is still continued an R&D and shall expect to install in FY2008.(3) We can also suggests to distinguish the Rayleigh scattering (air molecular) component and the Mie(aerosol) scattering componet from the data analysis within several percents resolution comparing with a theoretical prediction.Also we have installed an infra-red camera at BRM site in March 2008 to measure cloud and/or water vapour component in the atmosphere. Less