北斗和GPS反演大气可降水量的对比分析     

段晓梅  曹云昌 《气象》2018,44(12):1575-1582

北斗地基增强系统是我国北斗卫星导航系统重要的地面基础设施,它可以获取高精度、高时间分辨率的水汽产品,满足数值预报、空间天气监测和预警业务的需求。本文利用2017年北斗地基增强系统中北斗单模、GPS单模和GPS+BD双模的数据资料,对同址的北斗气象站、GPS气象站和探空站反演大气可降水量进行对比分析,结果表明:(1)现行北斗地基增强系统所提供的数据,可以有效地用来反演大气柱总水汽含量,所得结果合理,平均偏差都小于1 mm,在变化上与GPS系统和探空系统基本一致,对数值预报有一定的指示作用;(2)与GPS系统相比,GPS单模/PWV和GPS+BD双模/PWV的均方差小于2 mm,相关系数均在0. 97以上,表明两者在反演PWV的精度上与GPS系统相当,而北斗单模/PWV的均方差为3～6 mm,相对方差达到了15%～20%,其精度与GPS系统还有一定的差距;(3)与探空相比,北斗单模在个别时次变化趋势上存在不一致的情况,其均方差为2. 14～6. 12 mm,相对方差为15. 32%～20. 84%,其误差可能是由于探测系统误差等因素造成的,而GPS+BD双模和GPS单模会更加稳定。  相似文献   

Integration of air pollution data collected by mobile sensors and ground-based stations to derive a spatiotemporal air pollution profile of a city     

Yee Leung  Yu Zhou  Ka-Yu Lam  Tung Fung  Kwan-Yau Cheung  Taehong Kim 《International journal of geographical information science》2013,27(11):2218-2240

ABSTRACT

Air pollution has become a serious environmental problem causing severe consequences in our ecology, climate, health, and urban development. Effective and efficient monitoring and mitigation of air pollution require a comprehensive understanding of the air pollution process through a reliable database carrying important information about the spatiotemporal variations of air pollutant concentrations at various spatial and temporal scales. Traditional analysis suffers from the severe insufficiency of data collected by only a few stations. In this study, we propose a rigorous framework for the integration of air pollutant concentration data coming from the ground-based stations, which are spatially sparse but temporally dense, and mobile sensors, which are spatially dense but temporally sparse. Based on the integrated database which is relatively dense in space and time, we then estimate air pollutant concentrations for given location and time by applying a two-step local regression model to the data. This study advances the frontier of basic research in air pollution monitoring via the integration of station and mobile sensors and sets up the stage for further research on other spatiotemporal problems involving multi-source and multi-scale information.  相似文献   

青藏高原探空大气水汽偏差及订正方法研究   总被引：4，自引：1，他引：3  

梁宏  张人禾  刘晶淼  孙治安  李世奎 《大气科学》2012,36(4):795-810

水汽是大气的主要成分和降水的主要物质来源.青藏高原大气水汽分布对区域天气和气候有很大影响,为了探讨探空观测的大气水汽总量（R）资料的可靠性,本文以地基GPS遥感的大气水汽总量（G）为参照标准,对拉萨（1999~2010年）和那曲（2003年）的R进行对比分析和偏差（R-G）订正.结果表明:近10多年拉萨站R比G明显偏小,偏小程度随使用不同的探空仪而异.GZZ-2型机械探空仪和GTS-1型电子探空仪多年平均的PW偏差分别为-8.8%和-3.9%,随机误差分别为17.6%和13.6%.近10多年PW偏差变化呈减少趋势,这与探空仪性能改进有关.分析发现,青藏高原PW偏差具有明显季节变化和日变化特征,夏季比冬季明显,1200 UTC比0000 UTC明显.拉萨站GZZ-2型和GTS-1型探空仪在1200 UTC多年平均的PW偏差分别为-15.8%和-7.3%,在0000 UTC分别为-1.6%和-0.4%.那曲站GZZ-2型探空仪在1200 UTC和0000 UTC的PW偏差分别为-12.4%和-0.3%.分析还表明,太阳辐射加热与气温的日变化和季节变化是造成高原PW偏差日变化和季节变化的重要原因.据此,提出了高原PW偏差的订正方法,并以拉萨和那曲站为例进行PW偏差订正,订正后的PW系统偏差显著减少,随机误差也相应得到了改善.  相似文献   

利用BERNESE 5.0解算地基GPS天顶湿延迟     

王晓英  宋连春  曹云昌  戴仔强 《气象科技》2012,40(1):41-45

地基GPS技术已被公认为观测大气水汽的最具潜力手段,而天顶湿延迟（ZWD）是地基GPS解算高精度水汽的关键量。瑞士伯尔尼大学天文研究所开发的BERNESE软件在解算天顶湿延迟方面独树一帜。以香港地基GPS连续运行参考站数据为解算实例,详细介绍了BERNESE软件解算ZWD的基本步骤和相关设置,并对有气象观测文件、数据跨天、跨周和定点解算ZWD情况的特殊设置进行了研究,结果表明BERNESE软件完全胜任ZWD解算工作。  相似文献   

基于北斗导航系统的我国地基增强格网模型研究     

李志才  张鹏  郑福  罗小敏 《地理信息世界》2017,24(2)

基于全国均匀分布的210个北斗地基增强基准站观测数据,提出基于非差非组合精密单点方法获取空间相关的延迟误差及残差,研究利用反距离加权法、克里金插值法以及球谐函数法建立了中国区域的三种地基增强格网模型。使用单频伪距单点定位方法对中国区域的北斗地基增强格网模型定位精度进行了评估,验证结果表明本文建立的格网模型的定位精度达到米级,可满足大众用户的需求。  相似文献   

利用湖南CORS网监测分析湘北一次局地暴雨水汽场时空变化     

李黎  江婷  田莹  谢建  袁志敏 《大地测量与地球动力学》2017,37(8):835-840

基于72个湖南连续运行参考站 (CORS) 反演得到的可降水量 (PWV) ,针对2015-04-03~04-04湘北地区一次局地暴雨,结合温度和气压等大气热动力条件,分析湖南省PWV时间序列及其平面动态分布变化,并总结此次暴雨过程中水汽场变化规律。研究结果表明,作为降水的必要条件,PWV峰值越大降水概率越高,当PWV突破48 mm并首次降低时,随后1 h内会出现降水;当PWV持续增强达到峰值50 mm之后再次下降时,PWV增量变化很大程度上决定着雨势的大小及降雨持续时长;气温和气压等热动力条件也对雨势预测有一定的指示作用;PWV分布变化可对实际降水范围（落区）趋势作出较为准确的预测。  相似文献   

基于奇异谱分析的地基GPS反演可降水量可行性分析     

毛鹏宇  陈义  孟鑫 《大地测量与地球动力学》2017,37(9):933-936

对微波辐射计观测与地基GPS反演的可降水量数据分1个长时段和2个短时段进行奇异谱分析,提取两种数据在不同时段的主体趋势及周期项,验证地基GPS反演可降水量的可行性。结果表明,与微波辐射计观测数据相比,地基GPS反演可降水量数据均方根误差在2 mm左右,主体趋势具有较强的相关性,周期相同或相近,利用地基GPS反演可降水量是可行的。  相似文献   

Depletion of Column Ozone in the Arctic During the Winters of 1993-94 and 1994-95     

F. Goutail  J.-P. Pommereau  C. Phillips  C. Deniel  A. Sarkissian  F. Lefèvre  E. Kyro  M. Rummukainen  P. Ericksen  S.B. Andersen  B.-A. Kaastad-Hoiskar  G. Braathen  V. Dorokhov  V.U. Khattatov 《Journal of Atmospheric Chemistry》1999,32(1):1-34

The total ozone reduction in the Arctic during the winters of 1993/94 and 1994/95 has been evaluated using the ground-based total ozone measurements of five SAOZ spectrometers distributed in the Arctic and from number density profiles of a balloon-borne version of the instrument. The ozone change resulting from transport has been removed using a 3D Chemistry Transport Model (CTM) run without chemistry. A cumulative total ozone depletion at the end of winter in March of 18% ± 4% in 1994 and of 32% ± 4% in 1995 was observed within the polar vortex, and of 15% ± 4% in both years outside the vortex. This evaluation is not sensitive to the vertical transport in the model. The periods, locations and altitudes at which ozone loss occurred were tightly connected to temperatures lower than NAT condensation temperature. The maximum loss was observed at 50 hPa in 1994 and lower, 60-80 hPa, in 1995. Half of the depletion in 1994 and three quarters in 1995 occurred during the early winter, showing that a late final warming is not a prerequisite for large ozone destruction in the northern hemisphere. The timing, the geographical location and the altitude of the ozone losses are well captured by the 3D CTM photochemical model using current chemistry, but its amplitude at low sun during the early winter, is underestimated. The model simulations also capture the early season reductions observed outside the vortex. This suggests that the losses occurred in situ in the early winter, when low temperatures are frequent, and not later in March, when ozone is most reduced inside the vortex, which would be the case if leakage from the vortex was the cause of the depletion.  相似文献   

国内外GPS气象学的若干研究应用进展   总被引：1，自引：0，他引：1  

陈笑娟  扈成省  王占伟 《测绘科学》2010,35(3)

GPS气象学是一门新的交叉学科。本文介绍了GPS气象学基本原理、特点和分类,以及国内外GPS气象学的研究和应用方面的若干进展。  相似文献   

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唐超华  李陶  施闯  张诗玉 《大地测量与地球动力学》2009,29(2):106-110

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