نتایج جستجو برای: geoid
تعداد نتایج: 931 فیلتر نتایج به سال:
We review the procedures and challenges that must be considered when using geoid data derived from the Gravity and steady-state Ocean Circulation Explorer (GOCE) mission in order to constrain the circulation and water mass representation in an ocean general circulation model. It covers the combination of the geoid information with time-mean sea level information derived from satellite altimeter...
Fast and accurate relative positioning for baselines less than 20 km in length is possible using dual-frequency Global Positioning System (GPS) receivers. By measuring orthometric heights of a few GPS stations by dierential levelling techniques, the geoid undulation can be modelled, which enables GPS to be used for orthometric height determination in a much faster and more economical way than ...
A long-standing question is whether old oceanic lithosphere continues cooling as the boundary layer of a halfspace or approaches thermal equilibrium, as modeled by a finite thickness plate. Although the latter is the most direct inference from seafloor depths and heat flow, other explanations have been proposed. We investigate this issue using published results for the derivative of the oceanic...
The high-degree Earth Gravitational Model EGM08 allows for geoid determination with a resolution of the order of 5'. Using this model for estimating the quasigeoid height, we estimate the global root mean square (rms) commission error to 5 and 11 cm, based on the assumptions that terrestrial gravity contributes to the model with an rms standard error of 5 mGal and correlation length 0.01◦ and 0...
Introduction: The Venusian geoid, gravity field, and topography have been used in a variety of applications and are the primary sources of information about the internal structure of the planet. We focus on the relationship between the geoid and topography to determine both the support mechanism for the topography and lithospheric density structure. Magnitude of Dynamic Topography: The long-wav...
The objective of this paper is to introduce and describe the concept of using airborne gravimetry by strapdown INS/DGPS to reference mapping products derived from Interferometric Synthetic Aperture Radar (IFSAR) to the geoid. Calgary-based Intermap Technologies Ltd. is a digital mapping company that focuses on providing digital elevation models and ortho-rectified images using an interferometri...
to solve the geodetic boundary-value problem the gravity anomalies have to be continued from the earth's surface down onto the geoid surface. helmert’s gravity anomalies (multiplied by the geocentric radius) are harmonic above the geoid. it is thus possible to use them in the poisson solution of the inverse dirichlet boundary value problem to get their values on the geoid. the downward con...
Monthly gravity field estimates made by the twin Gravity Recovery and Climate Experiment (GRACE) satellites have a geoid height accuracy of 2 to 3 millimeters at a spatial resolution as small as 400 kilometers. The annual cycle in the geoid variations, up to 10 millimeters in some regions, peaked predominantly in the spring and fall seasons. Geoid variations observed over South America that can...
nowadays, combination of gps heights with orthometric heights, derived from precise leveling, is broadly used to obtain point-wise solutions of the geoid, which is called “gps/leveling geoid”. the “gps/leveling geoid” is commonly used to constrain the gravimetric geoid solutions in a least squares surface fitting process. in this paper, unlike the usual application, the “gps/leveling geoid” is ...
Geoid anomalies over the Pacific plate show lineated undulations approximately oriented in the direction of absolute plate motion. Conventional spectral analyses have revealed a broad range of dominant wavelengths, but as filtering is direction-dependent, results are difficult to interpret. Here, we present a new approach designed to quantify the correlation between the geoid undulations and Pa...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید