雾灵山GPS掩星观测实验分析  

Mountain-based GPS Occultation Observation Experiment at Mt Wuling

作　　者：宫晓艳[1] 胡雄[1] 吴小成[1] 张训械[2] 宋淑丽[1] 

机构地区：[1]中国科学院空间科学与应用研究中心 [2]中国科学院武汉物理与数学研究所,武汉430071

出　　处：《应用气象学报》2008年第2期180-187,共8页Journal of Applied Meteorological Science

基　　金：国家自然科学基金项目(40204011);中国科学院知识创新方向性项目(KGCX2-SW-408);航天领域高技术课题;中国气象局科技发展司社会公益项目(CMATG2005M08)共同资助

摘　　要：在高山的山顶上,利用GPS接收机跟踪低仰角和负仰角的GPS卫星信号,即山基GPS掩星观测,该技术可以获得低层大气折射指数剖面。2005年8月1—29日,在河北雾灵山(40.60°N,117.48°E,海拔2118 m)开展了山基GPS掩星观测实验,共获得576 h的原始观测数据,跟踪到掩星事件共1136次,其中621次上升掩星事件,515次下降掩星事件,平均每小时观测到2次掩星事件,经反演成功获得939个大气折射指数剖面。分析结果表明:山基掩星事件发生时间(地方时)大体呈平均分布;山基掩星事件持续时间大部分在15~20 min;山基掩星事件跟踪最低负仰角分布的峰值出现在-3°^-2.5°之间,所跟踪到的最低负仰角达到-4.994°,出现在正南稍偏东方向;下降掩星事件的最低仰角分布明显低于上升掩星事件的最低仰角分布。上述实验结果表明:山基掩星观测每天可为低层大气环境监测提供大量时空分布的折射率数据,具有潜在的应用前景。Mountain-based GPS occultation technique is referred to as receiving the radio signals of GPS satellites with very low elevations and negative elevations using a GPS receiver at the top of high mountain and retrieving the lower atmospheric refractivity profiles. A mountain-based GPS occultation observation experiment is performed at Mt Wuling（40.60°N, 117.48°E, 2118 m） in Hebei Province during August 1-29, 2005. The campaign is organized by China Meteorological Administration, a few other organizations participate in the experiment. Totally 576-hour raw observation data are collected by JAVAD two-frequency GPS receiver provided by Center for Space Science and Applied Research, Chinese Academy of Sciences, and 1136 occultation events are recorded. Out of the total occultation events, 621 are rising occultation events and 515 are setting occultation ones. There are about 2 occultation events observed in one hour on average. Detailed statistics and analyses are made to show features of all the observed occultation events, such as the distribution of the occurring time, the duration, minimum elevations and azimuth. The results are as follows. The distribution of the occurring time of the observed mountaln-based occultation events is nearly random uniform, and it seems that there are more observed occultation events for two periods of time, one is from 20：00 （local time） to 22：00, and the other is from 04：00 to 06：00. The duration of most occultation events is from 15 minutes to 20 minutes, and about 18 minutes on average. The range of azimuth of observed occultation events is between 110° and 290°, the peak of the distribution of azimuth is between 180° and 195°. These features are related to some important factors, such as the distribution of GPS satellites＇ orbits, the location of GPS receiver and the direction which the antenna points to. The minimum elevations of most occultation events are between - 3° and - 2.5°, the lowest negative elevations of all the events is - 4. 994° from south

关 键 词：山基GPS掩星技术 掩星事件 大气折射指数 最低仰角 

分 类 号：P228.4[天文地球—大地测量学与测量工程]