The Infrared Atmospheric Sounding Interferometer (IASI) is a new-generation ultraspectral atmospheric sounding instrument mounted on the MetOp-A, the first operational polar-orbiting satellite developed by the Europea...The Infrared Atmospheric Sounding Interferometer (IASI) is a new-generation ultraspectral atmospheric sounding instrument mounted on the MetOp-A, the first operational polar-orbiting satellite developed by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT). It is an ultrahigh spectral-resolution atmospheric detector which can detect atmospheric chemical composition, temperature, and humidity profiles with high accuracy and resolution. In the present study, through comparative analyses of the similarities and differences between the IASI and the radiosonde observation (RAOB) water vapor data, and between the IASI and the Aqua-AIRS water vapor retrievals, a detailed and systematic assessment of the credibility of the IASI water vapor retrievals over the plateau region was made. A comparison of the IASI retrievals with the AIRS retrievals and the RAOB measurements over the Tibetan Plateau revealed that the IASI retrieval data are reliable and can be used for conducting further studies.展开更多
Today, the GNSS （global navigation satellite system） is used for more complicate and accurate applications such as monitoring or stake out works. The truth lies in the fact that in the most of the times not enough a...Today, the GNSS （global navigation satellite system） is used for more complicate and accurate applications such as monitoring or stake out works. The truth lies in the fact that in the most of the times not enough attention is paid to the antenna＇s setup. Usually, gross errors are found in the antenna＇s centering, leveling and in the measurement of its height, which are significant. In this paper, a thoroughly analysis of the above mentioned errors is carried out. The influence of these errors in the calculation of the X, Y, Z Cartesian geocentric coordinates and the ~, 2, h ellipsoid geodetic coordinates of a point P on the earth＇s surface, is analyzed and is presented in several diagrams. Also a new convenient method for the accurate measurement of the antenna＇s height is presented and it is strongly proposed. The conclusions outline the magnitude of these errors and prove the significance of the antenna＇s proper setup at the accurate GNSS applications.展开更多
基金supported by the State Key Basic Research Development Program(Grant No.2012CB417204)the R&D Special Fund for Public Welfare Industry(Meteorology) by the Ministry of Finance and the Ministry of Science and Technology(Grant Nos.GYHY200806007,GYHY201006014,and GYHY201206039)the National Natural Science Foundation(Grant Nos.41175064,40875022,and 40633016)
文摘The Infrared Atmospheric Sounding Interferometer (IASI) is a new-generation ultraspectral atmospheric sounding instrument mounted on the MetOp-A, the first operational polar-orbiting satellite developed by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT). It is an ultrahigh spectral-resolution atmospheric detector which can detect atmospheric chemical composition, temperature, and humidity profiles with high accuracy and resolution. In the present study, through comparative analyses of the similarities and differences between the IASI and the radiosonde observation (RAOB) water vapor data, and between the IASI and the Aqua-AIRS water vapor retrievals, a detailed and systematic assessment of the credibility of the IASI water vapor retrievals over the plateau region was made. A comparison of the IASI retrievals with the AIRS retrievals and the RAOB measurements over the Tibetan Plateau revealed that the IASI retrieval data are reliable and can be used for conducting further studies.
文摘Today, the GNSS （global navigation satellite system） is used for more complicate and accurate applications such as monitoring or stake out works. The truth lies in the fact that in the most of the times not enough attention is paid to the antenna＇s setup. Usually, gross errors are found in the antenna＇s centering, leveling and in the measurement of its height, which are significant. In this paper, a thoroughly analysis of the above mentioned errors is carried out. The influence of these errors in the calculation of the X, Y, Z Cartesian geocentric coordinates and the ~, 2, h ellipsoid geodetic coordinates of a point P on the earth＇s surface, is analyzed and is presented in several diagrams. Also a new convenient method for the accurate measurement of the antenna＇s height is presented and it is strongly proposed. The conclusions outline the magnitude of these errors and prove the significance of the antenna＇s proper setup at the accurate GNSS applications.
