共查询到19条相似文献,搜索用时 187 毫秒
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介绍了GPS遥感大气水汽含量技术的类型、实时GPS遥感水汽技术的研究现状以及地基GPS大气探测的基本原理。提出了用非差精密单点定位模式进行实时GPS遥感水汽探测的基本构想和需要解决的关键问题,并对非差精密单点定位的主要误差源进行了简要分析和评述。 相似文献
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介绍了GPS遥感大气水汽含量技术的类型、实时GPS遥感水汽技术的研究现状以及地基GPS大气探测的基本原理.提出了用非差精密单点定位模式进行实时GPS遥感水汽探测的基本构想和需要解决的关键问题,并对非差精密单点定位的主要误差源进行了简要分析和评述. 相似文献
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InSAR大气水汽改正模型的比较应用研究 总被引:3,自引:1,他引:2
对基于GPS数据的大气水汽扰动模型(GPS topography-dependent turbulence model,GTTM)和GPS/MODIS集成的大气水汽改正模型进行了比较研究.试验证明,GTTM模型和GPS/MODIS集成模型的改正方法都可以大大降低大气水汽对InSAR测量地面形变量精度的影响.另外,当两种模型都用于改正InSAR观测值时,它们具有很强的互补性. 相似文献
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介绍了国际上InSAR观测值大气改正方法最新的研究进展,应用实例证明了由于大气(尤其是水汽)的影响,传统的InSAR形变量的监测精度往往只能限制在cm级;而利用GPS数据,通过基于地形的GPS扰动模型(GTTM),大幅度削弱了大气对干涉影像的影响,并成功地探测出了美国洛杉矾地区明显的季节性地表形变,形变量精度可提高到5mm左右。通过与GPS/MODIS集成大气改正模型的结果的比较表明,GTTM和GPS/MODIS两种大气改正模型在削弱InSAR观测值大气水汽影响方面具有很强的互补性。 相似文献
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基于MODIS与GPS的D-InSAR大气延迟改正量提取 总被引:1,自引:0,他引:1
受GPS站点密度的限制,利用GPS数据改正D-InSAR中大气延迟误差往往达不到很好的效果。为此,研究了GPS与MODIS联合实现大气延迟改正量提取方法,利用两期GPS观测数据及相应时间的MODIS数据分析GPS-PWV与MODIS-PWV的关系,进一步得到MODIS水汽的校正模型。经过GPS+MODIS算法改正后,大气延迟改正精度为3.618mm,满足形变测量的要求。实验结果表明:在大气状态变化缓慢时,利用GPS结合MODIS数据对D-InSAR大气延迟改正有一定的效果。 相似文献
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The Role of Ground-Based GPS Meteorological Observations in Numerical Weather Prediction 总被引:3,自引:0,他引:3
For lack of sufficient observations, the definition of atmospheric moisture fields (including water vapor and clouds) remains
a difficult problem whose solution is essential for improved weather forecasts. Moisture fields are under-observed in time
and space, primarily because the distribution of water in the atmosphere is highly variable. Because water is important in
weather and climate processes, a significant effort has been expended to develop new or improved remote sensing systems to
mitigate this problem. One such system uses ground-based Global Positoning System (GPS) receivers to make accurate all-weather
estimates of atmospheric refractivity at very low cost. This largely unanticipated application of GPS had led to a new and
potentially significant upper-air observing system for meteorological agencies and researchers around the world (Wolfe & Gutman,
2000). The first and most mature use of GPS for this purpose is in the estimation of integrated (total column) precipitable
water vapor above a fixed site (Duan et al., 1996, with improvements by Niell, 1996, and Fang et al., 1998). The techniques
currently used by the National Oceanic and Atmospheric Administration's Forecast Systems Laboratory (NOAA/FSL) to collect,
process, and distribute GPS water vapor observations are mature and almost ready for transition to operational use. NOAA/FSL
has shown that GPS integrated water vapor data can be used effectively in objective (i. e., numerical weather prediction)
and subjective weather forecasting. To understand the strengths and limitations of GPS for weather forecasting, it is essential
to understant what types of information are currently available to forecasters and modelers, and how models use the data to
describe the current and probable future state of the atmosphere. It is also important to understand the current trends in
modern weather prediction to ensure that GPS observing system play a significant role in the future. ? 2001 John Wiley & Sons,
Inc. 相似文献
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雾霾天气的形成与天气条件密切相关。GPS技术作为一种新的水汽探测手段,能高时效、高时空分辨率、自动实时、全天候地获取空气中的水汽含量。首先统计分析了雾霾的形成原因与变化规律,然后从GPS水汽、雾霾指数与空气相对湿度等方面进行了定性的相关性分析。研究结果表明,GPS水汽与雾霾天气的形成存在一定的相关性,GPS水汽在一定程度上可用于雾霾天气的监测与预报,而且气象部门可依据GPS水汽含量开展人工增雨(雪)来减缓雾霾天气的持续影响,进而为改善空气质量提供科学依据。 相似文献
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地基GPS技术遥感香港地区大气水汽含量 总被引:3,自引:0,他引:3
提出了分段多项式方法计算大气水汽含量,并结合无线电高空气象探测资料,分析并评估了地基GPS遥感技术的精度。香港地区的可降水份计算结果表明,地基GPS遥感技术的精度为1 m m ~2 m m 相似文献
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Estimating the motion of atmospheric water vapor using the Global Positioning System 总被引:1,自引:0,他引:1
Water vapor is both an important component in the atmosphere for the transport of energy and a noise source for space geodetic
observations of the Earth's surface, such as from GPS and interferometric SAR (InSAR) measurements. GPS data collected from
ground receivers are sensitive to the total amount of water vapor above the antenna and data from continuously operating GPS
receivers are routinely used to estimate delays caused by atmospheric water vapor. Using these time series of atmospheric
delay, we have estimated the motion of atmospheric water vapor above GPS networks. The motion above each site is determined
by comparing the time series from different sites and estimating relative time offsets in these time series. These are then
used to determine the velocity field of the atmospheric delays as they move across the network. We have compared the results
with similar estimates inferred from geostationary satellite data and found clear correlation on several occasions. Such results
can be useful for improving the understanding of the energy transport in the atmosphere, the spatial interpolation of water
vapor, and for calibrating InSAR observations for delays caused by water vapor.
Electronic Publication 相似文献
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Spatial and temporal resolution of water vapor content is useful in improving the accuracy of short-term weather prediction. Dense and continuously tracking regional GPS arrays will play an important role in remote sensing atmospheric water vapor content. In this study, a piecewise linear solution method was proposed to estimate the precipitable water vapor (PWV) content from ground-based GPS observations in Hong Kong. To evaluate the solution accuracy of the water vapor content sensed by GPS, the upper air sounding data (radiosonde) that are collected locally was used to calculate the precipitable water vapor during the same period. One-month results of PWV from both ground-based GPS sensing technique and radiosonde method are in agreement within 1–2 mm. This encouraging result will motivate the GPS meteorology application based on the establishment of a dense GPS array in Hong Kong. 相似文献
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Spatial and temporal resolution of water vapor content is useful in improving the accuracy of short-term weather prediction.Dense and continuously tracking regional GPS arrays will play an important role in remote sensing atmospheric water vapor content.In this study,a piecewise linear solution method was proposed to estimate the precipitable water vapor (PWV) content from ground-based GPS observations in Hong Kong.To evaluate the solution accuracy of the water vapor content sensed by GPS,the upper air sounding data (radiosonde) that are collected locally was used to calculate the precipitable water vapor during the same period.One-month results of PWV from both ground-based GPS sensing technique and radiosonde method are in agreement within 1~2 mm.This encouraging result will motivate the GPS meteorology application based on the establishment of a dense GPS array in Hong Kong. 相似文献
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4D GPS water vapor tomography: new parameterized approaches 总被引:1,自引:1,他引:0
Water vapor is a key variable in numerical weather prediction, as it plays an important role in atmospheric processes. Nonetheless,
the distribution of water vapor in the atmosphere is observed with a coarse resolution in time and space compared to the resolution
of numerical weather models. GPS water vapor tomography is one of the promising methods to improve the resolution of water
vapor measurements. This paper presents new parameterized approaches for the determination of water vapor distribution in
the troposphere by GPS. We present the methods and give first results validating the approaches. The parameterization of voxels
(volumetric pixels) by trilinear and spline functions in ellipsoidal coordinates are introduced in this study. The evolution
in time of the refractivity field is modeled by a Kalman filter with a temporal resolution of 30 s, which corresponds to the
available GPS-data rate. The algorithms are tested with simulated and with real data from more than 40 permanent GPS receiver
stations in Switzerland and adjoining regions covering alpine areas. The investigations show the potential of the new parameterized
approaches to yield superior results compared to the non parametric classical one. The accuracy of the tomographic result
is quantified by the inter-quartile range (IQR), which is decreased by 10–20% with the new approaches. Further, parameterized
voxel solutions have a substantially smaller maximal error than the non parameterized ones. Simulations show a limited ability
to resolve vertical structures above the top station of the network with GPS tomography. 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