Detection of major geological structures in the Eastern offshore of India using Geosat altimeter data     

T. J. Majumdar  K. K. Mohanty  A. K. Srivastava 《Journal of Earth System Science》1997,106(1-2):27-32

Satellite altimetry can be used to infer subsurface geological structures analogous to gravity anomaly maps generated through ship-borne survey. The Eastern offshore was taken up for analysis using Geosat Exact Repeat Mission (ERM) altimeter data. A methodology is developed to use altimeter data as an aid to offshore hydrocarbon exploration. Processing of altimeter data involves corrections for various atmospheric and oceanographic effects, stacking and averaging of repeat passes, cross-over correction, removal of deeper earth and bathymetric effects, spectral analysis and conversion into free-air gravity anomaly. The final processed results were derived for Eastern offshore in the form of prospecting geoid and gravity anomaly maps and their spectral components. The highs and lows observed in those maps were derived in terms of a number of prominent megastructures e.g., gravity linears, 85°E and 90°E ridges, the Andaman trench complex etc. Satellite-derived gravity profiles along 12°N latitude match well with the existing structures.  相似文献   

电法勘探的发展和展望   总被引：9，自引：1，他引：9       下载免费PDF全文

何继善 《地球物理学报》1997,40(Z1):308-316

电法勘探在经历了近一个世纪的发展后，其方法理论、仪器设备、野外数据采集、处理和解释等方面都经历了一系列重大变化．本文以方法理论的进展为主线，回顾、展望了目前电法勘探中几个重要而令人关注的研究焦点．这些问题的研究进展将会对21世纪的电法勘探产生深远的影响．  相似文献   

2002年秋季山东省干旱遥感监测分析   总被引：2，自引：0，他引：2  

赵玉金  赵红  刘文  刘欣  张璇  薛晓萍 《国土资源遥感》2004,15(1):65-67,77

利用极轨气象卫星遥感资料对2002年山东省秋季干旱进行监测和服务,其监测方法主要采用热惯量法。为了提高土壤水分模式的计算精度,将全省分为4个区域,对利用卫星资料反演的地表温度日较差进行植被指数等环境因素订正。在地理信息系统支持下,比较准确地计算出农田受旱面积,效果良好。  相似文献   

The gravity field and GGOS     

R. Forsberg  M.G. Sideris  C.K. Shum   《Journal of Geodynamics》2005,40(4-5):387

The gravity field of the earth is a natural element of the Global Geodetic Observing System (GGOS). Gravity field quantities are like spatial geodetic observations of potential very high accuracy, with measurements, currently at part-per-billion (ppb) accuracy, but gravity field quantities are also unique as they can be globally represented by harmonic functions (long-wavelength geopotential model primarily from satellite gravity field missions), or based on point sampling (airborne and in situ absolute and superconducting gravimetry). From a GGOS global perspective, one of the main challenges is to ensure the consistency of the global and regional geopotential and geoid models, and the temporal changes of the gravity field at large spatial scales. The International Gravity Field Service, an umbrella “level-2” IAG service (incorporating the International Gravity Bureau, International Geoid Service, International Center for Earth Tides, International Center for Global Earth models, and other future new services for, e.g., digital terrain models), would be a natural key element contributing to GGOS. Major parts of the work of the services would, however, remain complementary to the GGOS contributions, which focus on the long-wavelength components of the geopotential and its temporal variations, the consistent procedures for regional data processing in a unified vertical datum and Terrestrial Reference Frame, and the ensuring validations of long-wavelength gravity field data products.  相似文献   

On core surface flows inferred from satellite magnetic data     

Céline Eymin  Gauthier Hulot 《Physics of the Earth and Planetary Interiors》2005,152(3):200-220

Satellite-data allows the magnetic field produced by the dynamo within the Earth’s core to be imaged with much more accuracy than previously possible with only ground-based data. Changes in this magnetic field can in turn be used to make some inferences about the core surface flow responsible for them. In this paper, we investigate the improvement brought to core flow computation by new satellite-data based core magnetic field models. It is shown that the main limitation now encountered is no longer the (now high) accuracy of those models, but the “non-modelled secular variation” produced by interaction of the non-resolvable small scales of the core flow with the core field, and by interaction of the (partly) resolvable large scales of the core flow with the small scales of the core field unfortunately masked by the crustal field. We show how this non-modelled secular variation can be taken into account to recover the largest scales of the core flow in a consistent way. We also investigate the uncertainties this introduces in core flows computed with the help of the frozen-flux and tangentially geostrophic assumptions. It turns out that flows with much more medium and small scales than previously thought are needed to explain the satellite-data-based core magnetic field models. It also turns out that a significant fraction of this flow unfortunately happens to be non-recoverable (being either “non-resolvable” because too small-scale, or “invisible”, because in the kernel of the inverse method) even though it produces the detectable “non-modelled secular variation”. Applying this to the Magsat (1980) to Ørsted (2000) field changes leads us to conclude that a flow involving at least strong retrograde vortices below the Atlantic Hemisphere, some less-resolved prograde vortices below the Pacific Hemisphere, and some poorly resolved (and partly non-resolvable) polar vortices, is needed to explain the 1980-2000 satellite-era average secular variation. The characteristics of the fraction of the secular variation left unexplained by this flow are also discussed.  相似文献   

Applications géodésiques du système DORIS à l'Institut géographique national     

Pascal Willis  Claude Boucher  Hervé Fagard  Zuheir Altamimi 《Comptes Rendus Geoscience》2005,337(7):653-662

IGN is in charge of the installation and maintenance of the DORIS orbit determination network. More recently, in collaboration with JPL, precise geodetic computations were performed. The goal of this paper is to recall the various historic contributions of IGN to the DORIS system in their international context and then to describe a new estimation technique developed for a multi-satellite mode, making full profit of a better modeling for satellites and ground clocks as well as tropospheric correction parameters. Derived geodetic results demonstrate a precision in the order of 1 cm for station positions. To cite this article: P. Willis et al., C. R. Geoscience 337 (2005).  相似文献   

利用卫星遥感资料反演感热和潜热通量的研究综述     

王开存  周秀骥  李维亮  刘晶淼  王普才 《地球科学进展》2005,20(1):42-048

区域平均感热和潜热通量是气象、水文、生态模式中的关键物理因子，卫星遥感反演为观测区域平均感热和潜热通量提供了可能。对利用卫星遥感资料反演地气通量的方法进行了总结和评述。首先描述了现在常用的反演方法，分析了方法中的各种假定对反演结果的影响，并对不同的模式反演结果进行了比较。还指出了评价卫星反演通量的精度时需要注意的问题。最后对该领域内现存的问题与发展方向进行探讨。  相似文献   

卫星臭氧资料的发展与应用     

刘寅  邹晓蕾 《气象学报》2016,74(1):1-17

随着卫星探测技术的进步、天气学和气候学理论的不断完善,以及高性能计算机广泛应用,卫星臭氧资料的种类得到极大丰富并被应用到多个研究领域中,取得了一系列重要成果。文中介绍了主要星载臭氧探测仪的发展概况,回顾了卫星臭氧资料在气象领域的应用研究成果,主要包括卫星臭氧资料在气旋或低压过程中、全球或区域臭氧的气候分布及变化特征、高原臭氧分布及变化特点、数值应用等方面的应用研究,并展望了卫星臭氧资料研究的未来发展趋势。   相似文献   

北斗卫星导航系统双差动力法精密定轨及其精度分析     

刘伟平  郝金明  田英国  于合理  张康 《测绘学报》2016,45(2):131-139

针对GEO卫星切向轨道分量与双差模糊度强相关的问题,对经典双差动力法进行了改进,提出联合使用载波相位和相位平滑伪距实现北斗系统精密定轨,并从理论上分析了以上处理策略的可行性及对模糊度固定的影响,然后结合北斗系统精密定轨特点,推导给出了利用QIF方法实现北斗卫星双差模糊度固定的基本原理,实测数据分析表明:联合载波相位和相位平滑伪距,既可降低相关性,又可兼顾精度,定轨效果优于经典双差动力法;利用QIF方法能够取得一定的模糊度固定效果,但受观测条件限制,北斗卫星双差模糊度固定成功率整体不高,双差模糊度固定之后对轨道的改进作用有限。  相似文献   

一种天绘一号卫星影像精确定位方法     

周欣  王海岩  杨国鹏 《测绘科学》2016,41(11):5-9,129

针对如何最大程度地减小天绘一号卫星RPC模型系统误差,真实反映像方坐标与物方坐标关系的问题,该文介绍了天绘一号卫星的基本情况及相应的RPC参数模型,给出了求解RPC参数的基本方法和流程。结合天绘一号卫星采用等效框幅式光束法平差进行无控定位的特点,利用平差后计算得到的加密点坐标,提出了一种基于像点仿射变换的RPC模型区域网平差方法,并进行了RPC参数修正。经天绘一号卫星精度检测实验表明,修正后的RPC参数能有效地弥补系统性误差,具有更高的定位精度。  相似文献