共查询到18条相似文献，搜索用时 156 毫秒
1.
利用地面气象观测资料确定对流层加权平均温度 总被引：13，自引：0，他引：13
地基ＧＰＳ气象学的核心思想是通过垂直方向上ＧＰＳ信号的湿分量延时确定出可降水分,而这两个物理量之间的转换必须使用对流层加权平均温度。本首先讨论了上述转换估计中加权平均温度的几种遏近方式及其容许误差,然后利用香港地区的地面和高空气象资料,采用逐步回归分析方法,建立了适合香港地区的对流层加权平均温度计算公式,通过数据分析表明,这个公式有效地消除了在香港地区使用Ｂｅｖｉｓ经验公式引起的系统误差,较好地 相似文献
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成都地区地基GPS观测网遥感大气可降水量的初步试验 总被引：7，自引：0，他引：7
利用首个成都地区地基GPS观测网2004年7～9月30s间隔的测量数据，通过Bernese GPS SoftwareV4．2解算出30min间隔的天顶总延迟量，结合自动气象站获得的气象资料计算出30min间隔的GPS遥感的大气可降水量。与根据气象探空站探测资料算出的可降水量进行统计对比，确定出本次GPS遥感可降水量试验的精度为3．09mm，两种可降水量时间序列呈现高度的一致性。同时验证了计算对流层加权平均温度的Bevis经验公式在成都地区的适用性。 相似文献
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在地基GPS水汽反演过程中,针对因大气加权平均温度的精度而影响大气可降水量计算结果精度的问题,文中采用回归分析方法对香港地区2006-2016年的探空数据进行研究,构建适用于香港地区的单因子以及多因子两种大气加权平均温度计算模型．并使用两种模型分别预测2017年加权平均温度,与多种经验公式结果以及真值进行对比,单因子和多因子模型与真值的偏差在－5 ～5 K范围内分别占比80.72％和85.26％,明显优于其他经验公式;且按季节分别建模对大气加权平均温度计算结果的精度并没有明显提高,但按昼夜分别建模能够使计算结果的精度得到明显的提高．因此为了能够使水汽反演计算时的精度得到提升,应当使用当地多年的探空气象资料构建适用于当地的加权平均温度计算模型,对于提高GPS反演大气水汽总量的精度具有重要意义. 相似文献
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本文根据长期的气象探空资料通过数值积分的方法算出每个时次的加权平均温度,然后在此基础上对Bevis回归经验公式进行订正;在加权平均温度模型的建立中,计算公式中系数a、b的求解由计算软件根据最小二乘原理快速结算。最后通过相应的数据模拟计算证明这种方法可以确定出适合昆明本地区的加权平均温度计算模型。 相似文献
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本文根据长期的气象探空资料通过数值积分的方法算出每个时次的加权平均温度,然后在此基础上对Bevis回归经验公式进行订正;在加权平均温度模型的建立中,计算公式中系数a、b的求解由计算软件根据最小二乘原理快速结算。最后通过相应的数据模拟计算证明这种方法可以确定出适合昆明本地区的加权平均温度计算模型。 相似文献
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GPS水汽遥感中加权平均温度获取方法研究 总被引：1，自引：0，他引：1
在利用地基GPS进行大气水汽遥感时,加权平均温度对水汽遥感结果起着重要作用。本文对加权平均温度的获取方法进行了列举和比较,其中经验公式方法既可以快速获取又可以满足水汽遥感精度,同时根据当地探空资料得出的局部加权平均温度模型可比通用加权平均温度模型的精度提高近6倍。 相似文献
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对流层顶与加权平均温度和可降水量（precipitable water vapor，PWV）之间存在很强的相关性，然而目前几乎没有学者讨论它对加权平均温度和PWV的影响。针对对流层顶对GNSS（global navigation satellite system）气象模型影响研究所存在的空白，基于已有学者提出的联系对流层顶和加权平均温度的公式，首次讨论中国区域对流层顶变化对加权平均温度的影响。在不损失公式精度的前提下，将该公式整理后得到对流层顶与加权平均温度的二次函数关系，分析了中国不同纬度区域的对流层顶对加权平均温度的影响，利用探空站观测数据得到了影响分布图。该图可以预测对流层顶对加权平均温度和PWV的影响。 相似文献
11.
LIU Yanxiong CHEN Yongqi LIU Jingnan 《地球空间信息科学学报》2001,4(1):14-18
1 ＩｎｔｒｏｄｕｃｔｉｏｎＩｎ ｇｒｏｕｎｄ＿ｂａｓｅｄＧＰＳＭｅｔｅｏｒｏｌｏｇｙ ,ｔｈｅ ｐｒｅｃｉｐ ｉｔａｂｌｅｗａｔｅｒｖａｐｏｒｉｓｃｏｎｖｅｒｔｅｄｆｒｏｍｔｈｅｗｅｔｚｅｎｉｔｈｄｅｌａｙｏｆｔｈｅＧＰＳｓｉｇｎａｌ.Ｑｕａｌｉｔａｔｉｖｅｌｙ ,ｔｈｅＰｒｅｃｉｐ ｉｔａｂｌｅＷａｔｅｒＶａｐｏｒ (ＰＷＶ)ｃａｎｂｅｒｅｌａｔｅｄｔｏｔｈｅＷｅｔＺｅｎｉｔｈＤｅｌａｙ (ＷＺＤ)ｂｙＰＷＶ =Ｆ·ＷＺＤＦ =1 0 6ρｖ·Ｒｖ· ｋ3Ｔｍ +ｋ2( 1 )ｗｈｅｒｅｔｈｅｍａｐｐｉｎｇｓｃａｌｅｆａｃｔ… 相似文献
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The weighted mean tropospheric temperature is a critical parameter in the conversion of wet zenith delay to precipitable water vapor in GPS Meteorology. This parameter can not be calculated from the radiosonde data in real time through the conventional methods. In this study, we first discuss the admissible error of weighted mean temperature to enable the accuracy of the conversion better than 1 mm, then summarize the performance of some of the existing methods. An empirical formula is established that satisfies the real-time requirement in GPS meteorology using Sequential Regression Analysis method. It is shown that this real-time formula as compared with other empirical methods is more accurate for local applications. 相似文献
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The estimates of total zenith delay are derived using Bernese GPS Software V4. 2 based on GPS data every 30 s from the first measurement experiment of a ground-based GPS network in Chengdu Plain of Southwest China during the period from July to September 2004. Then the estimates of 0.5 hourly precipitable water vapor (PWV) derived from global positioning system (GPS) are obtained using meteorological data from automatic weather stations (AWS). The comparison of PWV derived from GPS and those from radiosonde observations is given for the Chengdu station, with RMS (root mean square) differences of 3.09m. The consistency of precipitable water vapor derived from GPS to those from radiosonde is good. It is concluded that Bevis’ empirical formula for estimating the weighted atmospheric mean temperature can be applicable in Chengdu area because the relationship of GPS PWV with Bevis’ formula and GPS PWV with radiosonde method shows a high correlation. The result of this GPS measurement experiment is helpful both for accumulating the study of precipitable water vapor derived from GPS in Chengdu areas located at the eastern side of the Tibetan Plateau and for studying spatial-temporal variations of regional atmospheric water vapor through many disciplines cooperatively. 相似文献
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In ground-based GPS meteorology, weighted mean temperature is the key parameter to calculate the conversion factor which will be used to map zenith wet delay to precipitable water vapor. In practical applications, we can hardly obtain the vertical profiles of meteorological parameters over the site, thus cannot use the integration method to calculate weighted mean temperature. In order to exactly calculate weighted mean temperature from a few meteorological parameters, this paper studied the relation between weighted mean temperature and surface temperature, surface water vapor pressure and surface pressure, and determined the relationship between, on the one hand, the weighted mean temperature, and, on the other hand, the surface temperature and surface water vapor pressure. Considering the seasonal and geographic variations in the relationship, we employed the trigonometry functions with an annual cycle and a semi-annual cycle to fit the residuals (seasonal and geographic variations are reflected in the residuals). Through the above work, we finally established the GTm-I model and the PTm-I model with a $2^{\circ }\times 2.5^{\circ }(\mathrm{lat}\times \mathrm{lon})$ resolution. Test results show that the two models both show a consistent high accuracy around the globe, which is about 1.0 K superior to the widely used Bevis weighted mean temperature–surface temperature relationship in terms of root mean square error. 相似文献
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无气象要素的GPS对流层延迟推算可降水量的研究 总被引：2，自引：0，他引：2
本文针对武汉地区GPS气象网资料,进行了GPS对流层延迟直接推算可降水量的研究。在武汉东湖站GPS对流层延迟与无线电探空可降水量的比较中,两者具有很好的相关性,相关系数达到了0.93;推导了对流层延迟直接推算可降水量的模型,对模型结果进行了检验,在武汉东湖站的对流层延迟转换的可降水量与无线电探空可降水量的比较中,均方根为7.8mm,相关性为0.91,这说明了在没有气象数据的地区对流层延迟直接推算的可降水量可以作为气象短期预报的参考。 相似文献
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大气加权平均温度的准确获取对高精度的GPS水汽反演至关重要。文中基于线性回归理论,在分析加权平均温度与地面温度间相关性的基础上,采用一元线性拟合的方法,建立大气加权平均温度经验模型。最后,采用香港地区2006-2015年无线电探空资料对经验模型进行验证。实验结果表明,文中模型计算加权平均温度的整体均方根误差为2.356 K,较Bevis模型精度提高了41.94％,且季节变化对加权平均温度计算的影响并不明显;对于GPS水汽反演,采用本文经验模型反演水汽的均方根误差为1.807 mm,平均偏差为1.362 mm,能够满足GPS可降水量反演的精度,且优于Bevis模型。 相似文献
17.
LI Guoping HUANG Dingfa LIU Biquan CHEN Jiaona 《地球空间信息科学学报》2007,10(3):181-185
The estimates of total zenith delay are derived using Bernese GPS Software V4. 2 based on GPS data every 30 s from the first measurement experiment of a ground-based GPS network in Chengdu Plain of Southwest China during the period from July to September 2004. Then the estimates of 0.5 hourly precipitable water vapor (PWV) derived from global positioning system (GPS) are obtained using meteorological data from automatic weather stations (AWS). The comparison of PWV derived from GPS and those from radiosonde observations is given for the Chengdu station, with RMS (root mean square) differences of 3.09m. The consis- tency of precipitable water vapor derived from GPS to those from radiosonde is good. It is concluded that Bevis’ empirical formula for estimating the weighted atmospheric mean temperature can be applicable in Chengdu area because the relationship of GPS PWV with Bevis’ formula and GPS PWV with radiosonde method shows a high correlation. The result of this GPS measurement experiment is helpful both for accumu- lating the study of precipitable water vapor derived from GPS in Chengdu areas located at the eastern side of the Tibetan Plateau and for studying spatial-temporal variations of regional atmospheric water vapor through many disciplines cooperatively. 相似文献
18.
A globally applicable, season-specific model for estimating the weighted mean temperature of the atmosphere 总被引：3，自引：1，他引：2
In GPS meteorology, the weighted mean temperature is usually obtained by using a linear function of the surface temperature T s. However, not every GPS station can measure the surface temperature. The current study explores the characteristics of surface temperature and weighted mean temperature based on the global pressure and temperature model (GPT) and the Bevis T m–T s relationship (T m =?a?+?bT s). A new global weighted mean temperature (GWMT) model has been built which directly uses three-dimensional coordinates and day of the year to calculate the weighted mean temperature. The data of year 2005–2009 from 135 radiosonde stations provided by the Integrated Global Radiosonde Archive were used to calculate the model coefficients, which have been validated through examples. The result shows that the GWMT model is generally better than the existing liner models in most areas according to the statistic indexes (namely, mean absolute error and root mean square). Then we calculated precipitable water vapor, and the result shows that GWMT model can also yield high precision PWV. 相似文献