Gravity gradient aided inertial navigation reference map obtained by new Parker´s forward method

In order to obtain accurate gradient data and build the gravity gradient reference database for the gravity gradient aided inertial navigation system (GGAINS), the fast frequency method for digital elevation model forward gravity gradient was investigated in detail. The Parker´s forward method based on discrete cosine transform (DCT) had been deduced to calculate the full tensor gravity gradient, and then discussed the accuracy and efficiency by numerical experiment. The simulation tests and analysis under MATLAB environment show that, the suggested method has very small differences with the more accurate forward method such as rectangular prism integration method, and the edge effect error of gradient data can be decreased in comparison to Parker´s FFT forward method. Meanwhile, it gives better apparent advantages over calculating scale.