Analysis of the Grace Data Processing on the Commonly used Filtering Methods Spatial Filtering

According to the different GRACE data sources, the inversion methods of surface quality migration are divided into two categories. The first type is directly inversion based on the GRACE Level-2 Earth time-varying gravity field model, also known as the ?bit theory method?. This method was first proposed by Wahretal and is one of the most commonly used inversion methods. It has been widely used in research and development; the second type is inversion by Level-1B observation data, such as mass tumor (Mascon) method. This is a theoretical method. The method is briefly introduced below.