Download Free Regional Gravity Field Modeling With Adjusted Spherical Cap Harmonics In An Integrated Approach Book in PDF and EPUB Free Download. You can read online Regional Gravity Field Modeling With Adjusted Spherical Cap Harmonics In An Integrated Approach and write the review.

Master's Thesis from the year 2006 in the subject Geography / Earth Science - Cartography, Geographic Information Science and Geodesy, grade: 1.3, University of Applied Sciences Karlsruhe (Geomatik), course: Master of Geomatics, language: English, abstract: As further development of GOCA- (GNSS/LPS/LS-based Online Control and Alarm Systems) software, the Kalman filter was developed as additional module to monitor besides pure object point displacement also the velocity and the acceleration in a specified time interval. In this Master thesis the Kalman filter algorithm is modified, and additional capabilities are added. The additional capabilities include; first, a forecasting of expected displacement, velocity and acceleration to future. Second, computing the time at which the point displacement and velocity is expected to exceed the given critical values. Two estimation algorithms are used in the GOCA-Kalman filtering; first, least squares adjustment (L2-norm estimation). Second, L1-estimation. Data analysis of given projects were to be carried out and compared using both adjustment algorithms. To design and develop the GOCA-Kalman filter four steps are applied; first step, the GOCA-Kalman filter is realized and tested using MATLAB to create the mathematical algorithm and test the results of standard point given displacement, e.g. constant velocity displacement , parabola displacement, etc . Second step, a VC++ dynamic link library (.dll) is created. Third step, the DLL file was embedded in the GOCA software by calling the DLL file and its related libraries. And forth step, the Kalman filter graphics part had to be modified to show the state vector components (displacement, velocity, and acceleration) with their standard deviations, and additional the forecasted value and its standard deviation would be shown in the graphics part. Additional work is added to this master thesis to make artificial displacement GKA-files (GNSS/LPS/LS input files in the GOCA-software), where points displacements with linear, parabola etc are created. The software was realized using MATLAB GUI and named GKA-create.
We previously described (14,14) spherical-harmonic global adjustments of satellite altimetry using the AFGL short-arc technique supplemented with point masses to allow incorporation of short-wavelength geoidal detail. Recently, we have also investigated another technique to enhance short-wavelength detail: least squares collocation with noise. Both methods provide a means to determine a high resolution gravity field on a local, regional or global scale. Statistical comparisons of these two methods have been made in selected areas and the results tabulated.
Detailed information on the gravitational effect of the Earth's topographic and isostatic masses can be calculated by gravity forward modeling. Within this book, the tesseroid-based Rock-Water-Ice (RWI) approach is developed, which allows a rigorous separate modeling of the Earth's rock, water, and ice masses with variable density values. Besides a discussion and evaluation of the RWI approach, applications in the context of the GOCE satellite mission and height system unification are presented.
As alternatives to lengthy globally valid series representations of the geopotential, piecewise modeling for the gravity field is investigated. A degree 23 spherical harmonic representation is replaced by 1500 local gravity functions within the spherical shell from 1 to 1.2 earth radii. Worst case acceleration errors enter in the 7th significant digit, computational speed is improved by an order of magnitude. (Author).
Recent research aimed at improving the knowledge of the earth's gravity field and its fundamental surface, the geoid, has been based to a large extent on a short-arc mode of satellite altimetry. The global geoidal parameters have consisted of spherical harmonic potential coefficients, and the local parameters have consisted of point mass magnitudes. It is shown that an adjustment solely in terms of the point masses is not desirable due to the spherical approximation in the point-mass algorithm which would compromise the accuracy in the determination of the oceanic geoid, attainable with the SEASAT altimetry or with a similar high-precision observational system. A mathematical framework is provided in order to model observations such as the horizontal (north and east) and vertical gradients of gravity or gravity disturbance. This development is based on the tensor approach to theoretical geodesy and is mostly concerned with the second-order derivatives, along local Cartesian axes, of a general scalar function of position; the derivatives are expressed in spheroidal and, for a variety of practical applications, in spherical coordinates. The scalar function of position is specialized to represent the (total) earth's potential, the standard (or normal) potential and, especially, the disturbing potential.