Scientific Computation Platform for Geophysical Geodesy

This scientific computing platform for geophysical geodesy comprises two core systems: the Precise Approximation of Earth Gravity Field and Geoid (PAGravf4.5) and the Earth Tide Loading Effects and Deformation Monitoring System (ETideLoad4.5). These systems were independently developed over a decade by Dr. ZHANG Chuanyin from the Chinese Academy of Surveying and Mapping, synthesizing twenty years of his pioneering research.

Since opening the platform and its core source code to the public in September 2021, the initiative has sought to ameliorate the critical scarcity of such computational resources in the global geoscience education landscape. It aims to establish a cognitive framework and knowledge architecture for multi-source heterogeneous data fusion and collaborative technologies in geodesy, demonstrating the profound elegance and potential of the discipline. Ultimately, this effort catalyzes a strategic paradigm shift: transforming geodesy from a "descriptive measurement tool" into a "dynamic Earth system analyzer," and elevating geodetic education from a "technology-oriented" approach to a "problem-driven" philosophy.

Adhering strictly to the principles of physical geodesy, PAGravf4.5 establishes a unified analytical framework for computing diverse terrain effects across all external gravity field elements, significantly advancing capabilities in geophysical gravity exploration and gravity field data processing. The software employs a robust hybrid architecture that synergistically integrates spatial-domain boundary value problem (BVP) integrals with spectral-domain Spherical Radial Basis Function (SRBF) approximations. This enables full-space, all-element analytical modeling of the gravity field on and outside the geoid, utilizing multi-source, heterogeneous, varying-altitude, cross-distributed, and multi-type observations. Furthermore, PAGravf4.5 incorporates ingenious algorithms for gravity exploration modeling using multi-source heterogeneous geodetic data and for the optimization of height datums, thereby consolidating and expanding the practical utility of the Earth’s gravity field theory.

The two software packages were developed by QT C++ (Visual C++) for the user interface, Intel Fortran (Fortran90, 132 Columns fixed format) for the core function modules, and mathGL C++ for the geodetic data file visualization in the Visual Studio 2017 x64 integrated environment. PAGravf4.5 is composed of nearly 50 win64 executable programs with more than 500 function modules, and ETideLoad4.5 is composed of more than 50 win64 executable programs with nearly 600 function modules.

The scientific computing platform is suitable senior undergraduates, graduate students, scientific researchers, and engineering technicians in geodesy and geophysics, geology and geoscience, geomatics and geographic information, seismic and geodynamics, aerospace and satellite dynamics. You can design your own schemes and processes, then organize flexibly the related programs and functions, perform the scientific computations for geophycical geodesy.

There are the example files saved in the folder C:\PAGravf4.5_win64en\examples and C:\ETideLoad4.5_win64en\examples for each Win64 program, espectively. Each example includes the operation process file process.txt, some input-output data files and screenshots. The folder name of the example files is the same as the name of the window executable program.

Before the program to be used, it is recommended to run the program from the input-output example data files with comparing the screenshots and the process information in process.txt. It will take about 7 working days to complete all the example exercises for PAGravf4.5 or ETideLoad4.5. Thereafter, you can use the scientific computing platform alone.