下行L波段轨道法时间比对中Sagnac效应的计算     

刘晓刚  梁率  韩智超 《地理空间信息》2009,7(3):94-96

根据下行L波段轨道法进行时间比对的基本原理，详细介绍了Sagnac效应产生的原因。并以圆轨道地球静止同步卫星为例，推导了下行L波段轨道法时间比对中Sagnac效应在地心惯性系中的基本计算模型，给出了当地面站在赤道上和不在赤道上这两种情况下Sagnac效应的详细计算过程。  相似文献   

南海海盆重力异常场特征及构造演化   总被引：5，自引：0，他引：5  

姚运生  姜卫平  晁定波 《大地构造与成矿学》2001,25(1):46-54

卫星重力测高能提供高分辩率的空间重力异常资料。本文解译了南海地块细结构的重力异常特征 ,并探讨了南海海盆的形成与演化  相似文献   

SANARIS Project: A Satellite Network for Natural Risk Monitoring     

Tárraga  Marta  Garcia  Alicia  Ortiz  Ramon  Abella  Rafael  Peña  Javier 《Natural Hazards》2001,23(2-3):417-429

A new satellite communication system specificallydesigned for low-rate data applications has beendeveloped and prototyped. A validation project isproposed to install a pilot network to be operated for6 months. One of the target markets related tovolcanoes, has been selected, so that a group of usersis integrated in the project. A specific applicationfor this market will be developed regarding dataacquisition, processing, storage and dissemination todistant users. The feasibility of using the newsatellite system to provide a new Eutelsat service forlow-rate data applications, will be evaluated from theperformance of the pilot network. The system ofautomatic acquisition, field storage and communicationwith the local control center is already functioning,as well as the circulation of information viaInternet. The development of the application andtransmission via satellite to distant users is stillin an evaluation phase for the volcanoes of Timanfaya(Lanzarote, Canary Island), Vesuvius (Naples) and SeteCidades Caldera (Sao Miguel, Azores Islands).  相似文献   

卫星云图资料估计湿度的适时回归方法及其影响诊断   总被引：1，自引：3，他引：1  

吴诚鸥  沈桐立  王顺凤 《南京气象学院学报》2001,24(2):162-164

提出适时回归方法，由卫星云图资料估计湿度场，数理统计中的回归诊断是查找野点的有力方法，本文成功地运用回归诊断于卫星云图资料估计湿度场，提高了精确度，得到良好效果。  相似文献   

用GMS—5气象卫星资料遥感监测白天雾的研究   总被引：16，自引：2，他引：16  

李亚春  孙涵  李湘阁  唐勇  徐萌 《南京气象学院学报》2001,24(3):343-349

用日本GMS－5静止气象卫星的可见光通道和长波红外通道的资料，采用多通道合成和图像增强技术生成云雾彩色图像，分析了云雾的纹理特征、运动规律和消散规律，探讨了白天雾和低层云的遥感监测和识别方法，对沪宁高速公路沿线大雾进行了实时监测。  相似文献   

气象卫星探测资料在数值天气预报中的应用   总被引：2，自引：0，他引：2  

郑祚芳  沈桐立  张秀丽 《气象》2001,27(9):3-8

卫星遥感技术和其他非常规观测技术的发展和成熟，提供了大量的非实时、非完全、准连续的观测资料。与其他非常规观测资料相比，卫星观测资料具有水平分辨率高，观测面广阔，测量误差易于掌握等优点。分析和总结了目前卫星观测资料在数值天气预报模式中的应用情况，并对其未来发展做了一些有益的探讨。  相似文献   

Glonass Laser Ranging Accuracy With Satellite Signature Effect   总被引：1，自引：0，他引：1  

Toshimichi Otsubo  Graham M. Appleby  Philip Gibbs 《Surveys in Geophysics》2001,22(5-6):509-516

GLONASS satellites have been tracked by the worldwide laser ranging networkas well as by the GLONASS-borne microwave-based technique. Owing to thelarge size of their corner cube reflector arrays, the amount of ranging data is enough to determine their orbits from laser ranging data alone. We found, however, that the large size of the array affected the accuracy of measurement to an extent that is dependent on the characteristics of the ranging systems. An azimuthal variation of the reflector array response was also detected in observations from single-photon laser ranging. Orbital analysis reveals that the effect makes the measured range on average 22 mm shorter than expected in the absence of the large array, which explains more than half of the offset of 39 mm previously discovered between microwave and laser orbits.  相似文献   

Slicer Laser Altimetry In The Eastern Caribbean     

P. Jansma  G. Mattioli  A. Matias 《Surveys in Geophysics》2001,22(5-6):561-579

Data acquired by the airborne Scanning Lidar Imager of Canopies by EchoRecovery (SLICER) laser altimeter provided high-resolution digital topographicdata over Puerto Rico, the Dominican Republic and several of the Lesser AntillesIslands. The instrument was developed by the NASA-Goddard Space Flight Center.It has the capability of multibeam resolution of ground elevations beneath densecanopy areas. Data, therefore, can be used to generate a more accurate representation of the ground surface by removing the vegetation cover. Although internal precision is high (10 cm to 1 m), absolute accuracy is difficult to evaluate and depends on several factors, including the post-processed kinematic GPS (KGPS) flight path for the aircraft platform and clear identification of ground returns in the SLICER waveform. We compared topographic profiles from USGS 30 m and 1:250K DEMs for Puerto Rico with those generated by SLICER and with spot elevations derived from static and continuous GPS surveys. SLICER and KGPS surveys cross at six points in western Puerto Rico. Agreement between both elevation data sets is excellent and well fit (r = 0.921) by a linear model with a final residual bias of -0.501 m for SLICER ground returns relative to KGPS elevations. The agreement between SLICER and USGS 30 m DEMs is also very good with the largest errors associated with steep slopes and high vegetation cover. Residuals between KGPS and USGS 30 m DEMs are +1 ± 25 m, assuming a fixed uniform offset of +43.23 m between WGS84 and mean sea level.  相似文献   

Contributions of Satellite Laser Ranging to Past and Future Radar Altimetry Missions     

P. Exertier  P. Bonnefond  J. Nicolas  F. Barlier 《Surveys in Geophysics》2001,22(5-6):491-507

Satellite laser ranging (SLR) has proven avery efficient method for contributingto the tracking of altimetric satellites anddetermining accurately their orbitalthough hampered by the non-worldwide coverageand the meteorologicalconditions. Indeed, in some cases it is the onlymethod available to determinethe satellite orbit (e.g., the orbits of the ERS-1and Geosat-Follow-On missions).Moreover, any operational and non-weather dependenttechniques, like GPS,DORIS, PRARE, can exhibit systematic errors inpositioning and orbitography. Acomparison with SLR results allows to evidence sucherrors and vice versa. Fordoing that, two different approaches for determiningprecise orbits can beconsidered: one based on global orbit determination,the other on a short-arctechnique used to locally improve a global orbitdetermined by another trackingtechniques, such as DORIS or GPS. We can thusvalidate a global orbit andachieve orbit quality control to a level of2 to 3 centimeters at present and expectto achieve a level of 1 to 2 centimeters inthe near future. Errors induced bystation coordinates or by the gravity field(geographically correlated errors, forexample) can be estimated from SLR tracking data.Colocation experiments withdifferent techniques in the same geodetic siteplay also a key role to ensure preciserelationships between the geodetic referenceframes linked to each technique. Inparticular, the role of the SLR technique is tostrengthen the vertical component(including velocity) of the positioning, whichis crucial for altimetry missions.The role of SLR data in the modelling of the firstterms of the gravity field has finally to be emphasized,which is of primary importance in orbitography,whatever the tracking technique used.Another application of SLR technology is thesatellite altimeter calibration. Examples of past calibrationand future experiments are given, including theaccuracy we can expect from the Jason-1 and EnviSatspace oceanography missions.  相似文献   

Ice Sheet And Satellite Altimetry     

Frédérique Rémy  Benoît Legresy  Laurent Testut 《Surveys in Geophysics》2001,22(1):1-29

Since 1991, the altimeters of the ERS European Satellites allow the observation of 80% of the Antarctica ice sheet and the whole Greenland ice sheet: They thus offer for the first time a unique vision of polar ice caps. Indeed, surface topography is an essential data thanks to its capacity to highlight the physical processes which control the surface shape, or to test models. Moreover, the altimeter is also a radar which makes it possible to estimate the snow surface or subsurface characteristics, such as surface roughness induced by the strong katabatic wind or ice grain size. The polar ice caps may not be in a stationary state, they continue to respond to the climatic warming of the beginning of the Holocene, that is 18000 years ago, and possibly start to react to present climatic warming: the altimeter offers the unique means of estimating the variations of volume and thus the contribution of polar ice caps to present sea level change.  相似文献