Analysis on convergence of iteration method for potential fields downward continuation and research on robust downward continuation method
位场向下延拓迭代法收敛性分析及稳健向下延拓方法研究

Geomagnetic navigation is a brand new navigation technology and has very important significance for national defence. Spatial geomagnetic database is a precondition when implementing geomagnetic navigation. Potential field continuation is an effective method for designing geomagnetic database. Integral iteration method is a kind of stable downward continuation method for potential fields. This paper focuses on convergence analysis of integral iteration method, and proves that the method is convergent mathematically. This paper also analyses the robust performance of integral iteration method, and it concludes that when observed data contain noise, noise may be accumulated during iteration. A new wave-number domain downward continuation method is presented according to the idea of regulation method and incremental Wiener filer method. Model test shows that the new method is stable, robust and has a short computation time.