gravity anomalies

A number of factors can significantly affect the accuracy of height determination when applying the GNSS leveling method. In general, it is possible to distinguish those related to the process of GNSS observations and their post-processing, and those related to the selection of the geoid/quasi-geoid height model. This work focuses on aspects of GNSS leveling accuracy when choosing global geoid models. In particular, to better ensure accuracy, it is important to understand the significance of the heights tidal system selection of global geoid models.

Crystalline rocks of the Marmarosh massif of the Eastern Carpathians, taking into account based on the plate tectonics theory analysis of their characteristics and tectonic setting and the constructed cross-section of the local gravity anomalies, have been formed by the metamorphic rocks of Ryphean, Vendian, Cambrian and late Paleozoic as well as by the Meso-Cainozoic rocks in the south-eastern passive margin of the European plate.

In the paper the interpretation of planetary anomalies in the gravitational field of the Earth, Venus, Mars and Moon in their relationship with the internal inhomogeneous structure of those planets is considered. The model of the gravitational field of named planets up to 20th order and degree and the three-layer models (crust, mantle and core) of the planets and its planetary parameters was taken as the initial information for modelling.
 

Fast Fourier transformation (FFT) was considered which substantially saves time when processing large data arrays due to the summation in the spectral domain instead of the multiplication in the space ones. With using of space, aerial, terrestrial and marine gravimetric data the spatial distribution of gravity anomalies in Antarctic region territory on a uniform grid 2′×2′ was constructed and a terrain correction was introduced. Using of FFT-method the regional model of quasigeoid of Antarctic continent and adjoining water areas was constructed.

Isostasy analysis and interpretation of the isostatic state on Earth, Venus, Mars and Moon is provided. Crustal thickness maps and interpretation of possible estimates of compensation depth on tectonic planets are given.

Purpose. Investigation to study quasigeoid computations based on the regional gravimetric data and different types of nonorthogonal basis functions was assessed to be important. When measurements from only restricted regions of the Earth surface are available, global spherical harmonics loose their orthogonality in a limited region, so the determination of the coefficients of the model, usually by using the least squares method, is numerically unstable.

Objective. The main purpose is to research the requirements for calculation accuracy characteristics of the Earth's gravitational field (quasigeoid heights and plumb line deflection components) based on an analysis of existing methods and requirements to determine these characteristics. Methodology. Gravimetric method is the primary method for determining the height quasigeoid and plumb line deflection components for land and shelf areas. Initial data in this case are results of the gravimetric survey.

The aim of this article is the role and place of geodesy and gravimetry in the complex Earth Sciences and making recommendations for their using in various fields of knowledge of science. Problem and its relation with important scientific and practical tasks. In the article we consider some issues of the current state and prospects of geodesy and gravimetry. So modern geodesy – natural branch, which includes several areas: geodesy and topography, applied engineering or surveying, marine surveying, space geodesy, higher geodesy and physical geodesy and others.

We consider the method of constructing the local gravity field using technique called spherical cap harmonic analysis (SCHA). This approach involves using of  associated Legendre functions of integer degree and noninteger order. These functions form two sets of functions. They are mutually orthogonal over the spherical cap in each set. However, in general these functions are not orthogonal. Thus, for using both of these sets of functions it is traditionally used least squares method. However, for higher orders it is quite difficult to compute eigenvalues and norms of these functions.

It is considered the technique of constructing of two-dimensional models of the density distribution using continuous wavelet transform. It is realized an approbation of this technique on the profiles of gravity anomaly passing through the centers of major mascons of the Moon.