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Research of Impact of Geografical Latitute and Residual Ionospheric Noises on Informativeness of Measuring of Zenith Wet Delay of GPS Signals
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作者 A. Sh. Mehdiyev R. A. Eminov +1 位作者 N. Y. Ismayilov H. H. Asadov 《Positioning》 2015年第3期44-48,共5页
It is noted that necessity of further increase of accuracy of GPS positioning systems requires de-velopment of more perfect methods to compensate information losses occurred due to residual ionospheric delay by using ... It is noted that necessity of further increase of accuracy of GPS positioning systems requires de-velopment of more perfect methods to compensate information losses occurred due to residual ionospheric delay by using optimization procedures. According to the conditions of formulated optimization task, the signal/noise ratio in measurements of zenith wet delay depends on the second order ionospheric errors, geographic latitude and day of year. At the same time if we assume that the number of measurements at the fixed geographic site is proportional to geographic latitude and if we accept existence of only two antiphase scenarios for variation of residual ionospheric delay on latitude normed by their specific constant, there should be optimum functional dependence of precipitated water on latitude upon which the quantity of measuring information reaches the maximum. The mathematical grounding of solution of formulated optimization task is given. 展开更多
关键词 zenith wet delay Information Optimization GPS Measurements IONOSPHERE GEOGRAPHIC LATITUDE
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Monitoring Zenithal Total Delays over the three different climatic zones from IGS GPS final products:A comparison between the use of the VMF1 and GMF mapping functions 被引量:4
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作者 Benachour Labib Jianguo Yan +2 位作者 Jean-Pierre Barriot Fangzhao Zhang Peng Feng 《Geodesy and Geodynamics》 2019年第2期93-99,共7页
The International GNSS Service(IGS) final products(ephemeris and clocks-correction) have made the GNSS an indispensable low-cost tool for scientific research, for example sub-daily atmospheric water vapor monitoring. ... The International GNSS Service(IGS) final products(ephemeris and clocks-correction) have made the GNSS an indispensable low-cost tool for scientific research, for example sub-daily atmospheric water vapor monitoring. In this study, we investigate if there is a systematic difference coming from the choice between the Vienna Mapping Function 1(VMF1) and the Global Mapping Function(GMF) for the modeling of Zenith Total Delay(ZTD) estimates, as well as the Integrated Precipitable Water Vapor(IPWV) estimates that are deduced from them. As ZTD estimates cannot be fully separated from coordinate estimates, we also investigated the coordinate repeatability between subsequent measurements.For this purpose, we monitored twelve GNSS stations on a global scale, for each of the three climatic zones(polar, mid-latitudes and tropical), with four stations on each zone. We used an automated processing based on the Bernese GNSS Software Version 5.2 by applying the Precise Point Positioning(PPP)approach, L3 Ionosphere-free linear combination, 7 cutoff elevation angle and 2 h sampling. We noticed an excellent agreement with the ZTD estimates and coordinate repeatability for all the stations w.r.t to CODE(the Center for Orbit Determination in Europe) and USNO(US Naval Observatory) products, except for the Antarctic station(Davis) which shows systematic biases for the GMF related results. As a final step, we investigated the effect of using two mapping functions(VMF1 and GMF) to estimate the IPWV,w.r.t the IPWV estimates provided by the Integrated Global Radiosonde Archive(IGRA). The GPS-derived IPWV estimates are very close to the radiosonde-derived IPWV estimates, except for one station in the tropics(Tahiti). 展开更多
关键词 International GNSS Service (IGS) VIENNA MAPPING FUNCTION 1 (VMF1) Global MAPPING FUNCTION (GMF) Precise Point Positioning (PPP) zenith TOTAL delay (ZTD) zenith wet delay (zwd) Integrated Precipitable Water Vapor (IPWV)
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哨兵1号的对流层湿延迟变化提取与分析 被引量:3
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作者 郭秋英 黄守凯 +4 位作者 李德伟 赵耀 张立国 张海平 李国伟 《导航定位学报》 CSCD 2023年第2期203-210,共8页
为了进一步提高大气水汽反演的精度和可靠性,提出一种利用星载干涉合成孔径雷达(InSAR)提取对流层天顶湿延迟(ZWD,简称对流层湿延迟)的方法:以2020年1月至2020年3月覆盖济南及周边地区的哨兵1号卫星(Sentinel-1)数据为基础,采用欧洲中... 为了进一步提高大气水汽反演的精度和可靠性,提出一种利用星载干涉合成孔径雷达(InSAR)提取对流层天顶湿延迟(ZWD,简称对流层湿延迟)的方法:以2020年1月至2020年3月覆盖济南及周边地区的哨兵1号卫星(Sentinel-1)数据为基础,采用欧洲中期天气预报中心(ECMWF)第五代全球气候的大气再分析资料(ERA5)计算对流层干延迟分量;再利用双线性插值方法统一干延迟分量与Sentinel-1的分辨率;然后通过差分数据处理实现InSAR干涉图相位中对流层湿延迟分量的提取。实验结果表明,Sentinel-1数据可以在较高的空间分辨率内有效提取对流层湿延迟;InSAR技术与北斗卫星导航系统(BDS)技术探测的天顶方向对流层湿延迟变化趋势一致,且对流层湿延迟含量逐渐升高;2种探测手段的对流层湿延迟结果平均偏差为4.45~9.03 mm,最小偏差可达0.3 mm,二者相关系数为0.79。利用InSAR技术结合Sentinel-1等数据可以提取高精度、空间连续对流层湿延迟,可为大范围、空间连续的大气水汽反演提供数据支撑。 展开更多
关键词 星载干涉合成孔径雷达(InSAR) 哨兵1号 对流层湿延迟(zwd) 北斗卫星导航系统(BDS) 气象再分析资料
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A global empirical model for mapping zenith wet delays onto precipitable water vapor using GGOS Atmosphere data 被引量:6
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作者 YAO YiBin XU ChaoQian +1 位作者 ZHANG Bao CAO Na 《Science China Earth Sciences》 SCIE EI CAS CSCD 2015年第8期1361-1369,共9页
The importance of water vapor in research of global climate change and weather forecast cannot be over emphasized; therefore substantial efforts have been made in exploring the optimal methods to measure water vapor. ... The importance of water vapor in research of global climate change and weather forecast cannot be over emphasized; therefore substantial efforts have been made in exploring the optimal methods to measure water vapor. It is well-established that with a conversion factor, zenith wet delays can be mapped onto precipitable water vapor (PWV). However, the determination of the exact conversion factor depends heavily on the accurate calculation of a key variable, weighted mean temperature of the trop- osphere (Tin). AS a critical parameter in Global Positioning System (GPS) meteorology, Tm has recently been modeled into a global grid known as GWMT. The GWMT model only requires the location and the day of year to calculate Tm. Despite the advantages that the GWMT model offers, anomalies still exist in oceanic areas due to low sampling resolution. In this study, we refine the GWMT model by incorporating the global Tm grid from Global Geodetic Observing System (GGOS) and obtain an improved model, GWMT-G. The results indicate that the GWMT-G model successfully addresses the anomaly in oceanic areas in the GWMT model and significantly improves the accuracy of Tm in other regions. 展开更多
关键词 GPS meteorology zenith wet delay GWMT model GWMT-G model GGOS
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在高海拔地区Saastamoinen与Hopfield模型推算水汽含量差异的研究 被引量:10
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作者 曲建光 魏旭东 +1 位作者 王泽民 赵全胜 《武汉大学学报(信息科学版)》 EI CSCD 北大核心 2003年第4期397-399,416,共4页
详细分析了在高海拔地区利用Saastamoinen和Hopfield两种模型推算水汽含量时产生差异的原因 ,并通过对高程不同的测站上实测数据的分析和研究 。
关键词 高海拔地区 Saastamoinen HOPFIELD 模型 水汽含量 差异 大气延迟 GPS数据 ZHD zwd TND
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基于天顶湿延迟的GPS大气折射率剖面反演研究 被引量:4
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作者 林乐科 张业荣 +2 位作者 赵振维 王晓宾 刘琨 《全球定位系统》 2007年第3期1-4,26,共5页
利用青岛地区的历史探空数据,仿真得到其天顶湿延迟。基于天顶湿延迟和历史折射率剖面的统计关系,建立了折射率剖面的线性统计模型,回归得到模型参数。仿真比较结果表明,该方法优于常规气象模型,并有一定的容错性。
关键词 天项湿延迟 折射率剖面 GPS 反演
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从GPS推算大气水汽的误差分析 被引量:18
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作者 曲建光 吴壮 《测绘工程》 CSCD 2001年第4期24-26,共3页
讨论了从 GPS观测数据推算大气水汽值的各种误差,分析了这些误差对大气水汽值的影响。
关键词 天顶静力学延迟 天顶湿延迟 综合水汽含量 可降水份 大气水汽 GPS 全球定位系统
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Empirical model for mean temperature and assessment of precipitable water vapor derived from GPS
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作者 Tang Yanxin Liu Lilong Yao Chaolong 《Geodesy and Geodynamics》 2013年第4期51-56,共6页
The estimation of Precipitable Water Vapor (PWV) derived from Global Positioning System (GPS) data at the IGS site WUHN is assessed by comparing with PWV obtained from radiosonde data (No.57494) in Wuhan. The ap... The estimation of Precipitable Water Vapor (PWV) derived from Global Positioning System (GPS) data at the IGS site WUHN is assessed by comparing with PWV obtained from radiosonde data (No.57494) in Wuhan. The applicability of Saastamoinen (SAAS), Hopfield and Black models used for estimating Zenith Hydrostatic Delay (ZHD) and Zenith Wet Delay (ZWD) and different models is verified in the estimation of GPS-derived PWV for the applied area. The experimental results demonstrated that : 1 ) the precision of PWV estimated from Black model used for calculating ZHD ( ZHDs ) is lower than that of SAAS ( ZHDsAAs ) model and Hopfield model (ZHDn) with the RMS of 4. 16 ram; 2) the RMS of PWV estimated from SAAS model used for calculating ZWD (SAAS) is 3.78 ram; 3 ) the well-known Bevis model gives similar accuracy compared with the site-specific models for Tm in terms of surface temperature ( Ts ) and surface pressure (Ps), which can reach the accuracy inside 1 mm in the GPS-derived PWV estimates. 展开更多
关键词 GPS radiosonde data zenith Hydrostatic delay (ZHD) zenith wet delay(zwd) the weighted mean temperature of the atmosphere Precipitable Water Vapor(PWV)
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基于GPS和NCEP FNL数据改正InSAR大气延迟的可行性分析
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作者 张书毕 傅拓 《工程勘察》 CSCD 2012年第8期72-78,共7页
InSAR技术是近二十几年来迅速发展的极具应用价值的空间对地观测新技术,它具有监测精度高、范围大、成本低、空间连续覆盖等优点,为滑坡、泥石流等地质灾害监测提供了一种新型的监测方法。但由于地质灾害多发生在暴雨频发、地质地貌复... InSAR技术是近二十几年来迅速发展的极具应用价值的空间对地观测新技术,它具有监测精度高、范围大、成本低、空间连续覆盖等优点,为滑坡、泥石流等地质灾害监测提供了一种新型的监测方法。但由于地质灾害多发生在暴雨频发、地质地貌复杂的区域,特殊的地理位置与气候使得InSAR技术应用中受大气延迟的影响非常严重,导致InSAR图像错误解释。本文在全面回顾当前主流的几种改正InSAR大气延迟的方法在国内外滑坡监测中的应用现状和实例的基础上,分析这几种技术的优势及问题点,并结合最新技术进展提出了一种基于GPS和NCEP FNL数据改正InSAR大气延迟的新方法,详细推导了该方法处理的流程,结合实例进行了分析比较,证明了其可有效削弱InSAR干涉图中的残余大气延迟相位,进而提高InSAR监测精度的优点。 展开更多
关键词 滑坡监测 InSAR大气延迟 永久散射体 美国环境观测中心最终全球资料同化系统 天顶湿延迟
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利用GPS数据标校水汽辐射计的方法研究 被引量:4
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作者 窦世标 宋淑丽 +4 位作者 周伟莉 刘智敏 陈钦明 郑为民 陈后财 《天文学报》 CSCD 北大核心 2018年第6期74-83,共10页
对流层是影响各类对地观测、地对空观测精度的主要因素之一.目前GNSS(Global Navigation Satellite System)技术由于其时空分辨率和精度方面的优越性,成为大气延迟和水汽监测的主要手段之一.水汽辐射计WVR (Water Vapor Radiometer)是... 对流层是影响各类对地观测、地对空观测精度的主要因素之一.目前GNSS(Global Navigation Satellite System)技术由于其时空分辨率和精度方面的优越性,成为大气延迟和水汽监测的主要手段之一.水汽辐射计WVR (Water Vapor Radiometer)是传统的大气探测手段,由于其观测原理和灵敏度等方面的特点,也有其特殊的用途. WVR在正式投入使用前必须根据各个测站的具体情况进行标校,一般采用探空数据来进行,但探空数据采样频率低、数据量小, GNSS具有相对的优势.利用分布于北京(BJMY)、上海(SHAO)、昆明(YNKM)、乌鲁木齐(URUM) 4个VLBI (Very Long Baseline Interferometry)台站的GPS和水汽辐射计数据,开展了利用GPS数据标校WVR的方法研究,探讨了各个台站WVR的数据预处理方法,分析了影响水汽辐射计测量精度的因素.利用2015–2016年的4个并置台站的GPS和WVR观测数据,验证水汽辐射计数据的稳定性与可靠性.采用归一化处理方法,利用GPS数据对水汽辐射计进行了校准,为水汽辐射计的标校提供了一种新的思路和方法. 展开更多
关键词 水汽辐射计 GPS 对流层延迟 天顶湿延迟 标校
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Retrieval of the Change of Precipitable Water Vapor by GPS Technique 被引量:9
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作者 WANG Yong LIU Yanping LIU Lintao XU Houze 《Geo-Spatial Information Science》 2007年第4期265-268,共4页
The feasibility of GPS precipitable water vapor (PWV) is discussed based on the comparison of Radiosonde and GPS PWV where the correlation coefficient is 0.94 and the RMS is 4.0 mm. PWV change in the Chinese mainlan... The feasibility of GPS precipitable water vapor (PWV) is discussed based on the comparison of Radiosonde and GPS PWV where the correlation coefficient is 0.94 and the RMS is 4.0 mm. PWV change in the Chinese mainland in 2004 is graphed with the gridding method of splines in tension, according to the GPS data of the crust monitor observation network in China, combined with relevant meteorology information. According to the distribution of the annual amount of rainfall in the country, it can be concluded that the total trend of the PWV is diminishing from the south-east coastland to the north-west inland. The PWV reaches its maximum during July and August, and the minimum is reached during January and February. According to the PWV, from high to low, all districts can be ranked as south-east coastland, the inland and the tableland. 展开更多
关键词 GPS-meteorology precipitable water vapor zenith wet delay zenith tropospheric delay
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Establishment and analysis of global gridded Tm-Ts relationship model 被引量:7
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作者 Zeying Lan Bao Zhang Yichao Geng 《Geodesy and Geodynamics》 2016年第2期101-107,共7页
In ground-based GPS meteorology, Tm is a key parameter to calculate the conversion factor that can convert the zenith wet delay(ZWD) to precipitable water vapor(PWV). It is generally acknowledged that Tm is in an ... In ground-based GPS meteorology, Tm is a key parameter to calculate the conversion factor that can convert the zenith wet delay(ZWD) to precipitable water vapor(PWV). It is generally acknowledged that Tm is in an approximate linear relationship with surface temperature Ts, and the relationship presents regional variation. This paper employed sliding average method to calculate correlation coefficients and linear regression coefficients between Tm and Ts at every 2°× 2.5° grid point using Ts data from European Centre for Medium-Range Weather Forecasts(ECMWF) and Tm data from "GGOS Atmosphere", yielding the grid and bilinear interpolation-based Tm Grid model. Tested by Tm and Ts grid data, Constellation Observation System of Meteorology, Ionosphere, and Climate(COSMIC) data and radiosonde data, the Tm Grid model shows a higher accuracy relative to the Bevis Tm-Ts relationship which is widely used nowadays. The Tm Grid model will be of certain practical value in high-precision PWV calculation. 展开更多
关键词 zenith wet delay Precipitable water vapor Ground-based GPS meteorology Weighted mean temperature Gridded Tm-Ts model
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Preliminary calibration results for Jason-3 and Sentinel-3 altimeters in the Wanshan Islands 被引量:1
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作者 Wanlin ZHAI Jianhua ZHU +3 位作者 Xiaohui FAN Longhao YAN Chuntao CHEN Zhen TIAN 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2021年第2期458-471,共14页
We present preliminary calibration results for Jason-3 and Sentinel-3A altimeters that we set up in the Wanshan Islands in Guandong Province,China.Two campaigns were carried out in 2018,from March 8 to April 16 and fr... We present preliminary calibration results for Jason-3 and Sentinel-3A altimeters that we set up in the Wanshan Islands in Guandong Province,China.Two campaigns were carried out in 2018,from March 8 to April 16 and from November 3 to December 11,2018.Three GPS reference stations and tide gauges were established on the islands of Zhiwan,Dangan,and Wailingding during the campaigns.The in-situ sea surface height(SSH)of the altimeter footprint was determined using the tide gauge.The tidal and geoid connection between the tide gauge locations and the altimeter footprints were computed with the NAO.99Jb tidal prediction system and the EGM 2008 geoid,respectively.The data of the tide gauges were defi ned using the GPS buoy and GPS reference stations during the campaigns.The results show that the waveform of the altimeters was slightly contaminated by the small islands.The bias associated with Jason-3 and Sentinel-3A amounted to approximately+20.7±49.7 mm and+30.1±39.4 mm,respectively,which agreed well with the results from other in-situ calibration fi elds.This indicates that the Wanshan area was very suitable as an in-situ calibration/validation fi eld.The wet zenith delay(WZD)determined from the Microwave Radiometer(MWR)and the GPS measurements diff ered from each other for the Jason-3 and Sentinel-3A by−6.6±7.4 mm and 0±6.8 mm,respectively. 展开更多
关键词 altimeter calibration tide gauge GPS buoy wet zenith delay
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一种改正InSAR大气延迟的新方法
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作者 傅拓 张书毕 《城市勘测》 2012年第2期89-92,共4页
InSAR技术是近二十几年来迅速发展的极具应用价值的空间对地观测新技术,具有监测精度高、范围大、成本低、空间连续覆盖等优点,为滑坡、泥石流等地质灾害监测提供了一种新型的监测方法。但由于地质灾害多发生在暴雨频发、地质地貌复杂... InSAR技术是近二十几年来迅速发展的极具应用价值的空间对地观测新技术,具有监测精度高、范围大、成本低、空间连续覆盖等优点,为滑坡、泥石流等地质灾害监测提供了一种新型的监测方法。但由于地质灾害多发生在暴雨频发、地质地貌复杂的区域,特殊的地理位置与气候使得InSAR技术应用中受大气延迟的影响非常严重,导致In-SAR图像错误解释。本文在全面回顾当前主流的几种改正InSAR大气延迟的方法在国内外滑坡监测中的应用现状和实例的基础上,分析这几种技术的优势及问题点,并结合最新技术进展提出了一种基于GPS和NCEP FNL数据改正InSAR大气延迟的新方法并详细推导了该方法处理的流程,证明了其可行性。 展开更多
关键词 InSAR大气延迟 永久散射体 美国环境观测中心最终全球资料同化系统 天顶湿延迟
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