基于三频载波组合的周跳探测方法研究     

王俊杰  徐东风 《测绘工程》2017,26(11)

针对GPS现代化的发展,采用L_1,L_2,L_5三种载波进行线性组合,进行周跳探测。实例表明:该组合具有较长的波长,可以降低测量噪声,其观测值模型对周跳非常敏感,可以探测出大于0.2周的周跳。  相似文献   

Simplified Model Of The Air Flow Above Waves     

V. N. Kudryavtsev  V. K. Makin  J. F. Meirink 《Boundary-Layer Meteorology》2001,100(1):63-90

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Feedback Mechanisms For The Atmosphere And Ocean Surface   总被引：4，自引：0，他引：4  

Yaocun Zhang  William Perrie 《Boundary-Layer Meteorology》2001,100(2):321-348

Two kinds of feedback mechanisms in the coupling process between the atmosphere and ocean surface are identified in this paper. One is a negative feedback mechanism, which is effective in the dynamic interaction processes through momentum flux exchange. In this mechanism,the ocean extracts momentum from the atmosphere as a forcing field to generate waves, which decelerates atmospheric motions, lessening the intensity of synoptic systems. The second is a positive feedback mechanism, which is effective in the thermal interaction processes through heat flux exchange. This is a mechanism that is effective in the transport of sensible and latent heat fluxes to the atmosphere from the underlyingocean surface. As a result, the atmosphere obtains energy from the ocean, which intensifies atmospheric motions. For storm conditions typical of North Atlantic mid-latitudes, we consider these thermal and dynamical nteractions, the dominance of one over the other, and related implications for storm intensification.  相似文献   

Nonlinear magneto-acoustic waves in the solar atmosphere     

Csar A. Mendoza-Briceo  Miguel H. Ibez  Valery M. Nakariakov 《Dynamics of Atmospheres and Oceans》2001,34(2-4)

The weakly nonlinear evolution of quasi-isentropic magnetoacoustic waves in the solar atmosphere is analyzed. The plasma is assumed to be initially homogeneous, in thermal equilibrium and with a straight and homogeneous magnetic field frozen in. Additionally, the plasma is assumed to be cooled by the standard cooling function in the range of 10⁴ K<T<10⁷ K and heated by a mechanism which is proportional to the density and temperature. The range of temperature where the plasma is isentropically unstable, the e-folding time for thermal instability and the corresponding time and length-scale for wave breaking are found.  相似文献   

Precise tidal gravity recorded with superconducting gravimeters at stations Wuhan (China) and Kyoto (Japan)   总被引：9，自引：0，他引：9  

H.-P. Sun  S. Takemoto  H.-T. Hsu  T. Higashi  A. Mukai 《Journal of Geodesy》2001,74(10):720-729

 Three long series of tidal gravity observations, totalizing approximately 24 years and recorded with three superconducting gravimeters, T004, T008, and T009, at stations Wuhan (China) and Kyoto (Japan), are studied. The tidal amplitude factors and phase differences are determined precisely using Eterna and Nsv techniques. The precision of the main tidal amplitudes is at the same level of 0.01 μGal. The atmospheric gravity signals are corrected using the coefficients determined with a regression method between tidal gravity residual and station air pressure. The oceanic gravity signals are modeled based on five global oceanic models. It is found that the oceanic models developed by the analysis of measurements from Topex/Poseidon altimeters have the best fit to the superconducting gravimeter measurements, since the observed residuals and the discrepancies between the amplitude factors and the theoretical tidal models are reduced more significantly. The long-period gravity variations are dominated by the non-linear drift phenomena of the instruments, and the short-term variations in gravity are due to the background noise at the stations. Received: 20 January 2000 / Accepted: 15 September 2000  相似文献   

波形反演方法及其在新疆地区转换波测深中的应用   总被引：3，自引：0，他引：3       下载免费PDF全文

范会吉  邵学钟 《地球物理学报》1997,40(3):369-379

利用天然地震记录直达P波后续20s内的波形信息,研究了地壳、土地慢速度结构反演的方法、唯一性、精度及应注意的问题,并将求解有条件极值的惩罚数法和求解无条件极值的单纯形法引入到波形反演.数值计算证明,波形反演方法对记录的误差有压制作用,在深源、远震、各向同性水平层状近似合理的前提下,可用一个地震事件在射线平面内的二分量记录反演台站区地壳、上地幔P、S波速度结构.在新疆天山地区转换波流动台站观测中,选择出较好的记录进行波形反演,给出了该转换被测深剖面上6个台站下方的地壳、上地慢P、S波速度结构.通过塔里木盆地内一测点上波形反演和地震勘探结果的对比证明,波形反演方法具有满意的精度.  相似文献   

Seismic source functions for explosions in a non-spherical cavity embedded in a scattering environment: application to the regional discrimination of nuclear explosions and earthquakes     

Ari Ben-Menahem 《Geophysical Journal International》1997,128(1):97-124

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Determination of S-wave energy release of earthquakes in the region of Friuli, Italy     

Raúl R. Castro  Francesca Pacor  Carmine Petrungaro 《Geophysical Journal International》1997,128(2):399-408

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On the onset of P seismograms     

A. Douglas  D. Bowers  J. B. Young 《Geophysical Journal International》1997,129(3):681-690

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The rupture history of the M_w 8.0 Jalisco, Mexico, earthquake of 1995 October 9     

Vyacheslav M. Zobin 《Geophysical Journal International》1997,130(1):220-228

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