Using the Integer Decorrelation Procedure to Increase of the Efficiency of the Mafa Method

Abstract

Using the Integer Decorrelation Procedure to Increase of the Efficiency of the Mafa MethodThe Modified Ambiguity Function Approach (MAFA) is a method of GNSS carrier phase processing. In this method, the functional model of the adjustment problem contains the conditions ensuring the "integerness" of the ambiguities. These conditions are expressed in the form of differentiable function. A prerequisite for obtaining the correct solution is a mechanism ensuring not only the "integerness" of the ambiguity but also appropriate localization of the search space in the place where the ambiguities have correct values. One of such mechanisms is cascade adjustment, applying the linear combinations of the signals L1 and L2 with the integer coefficients and various wavelengths. This paper presents another, independent from the previous, approach to increase the efficiency of the MAFA method. It is based on the application of the integer decorrelation matrix to transform observation equations into equivalent, but better conditioned, observation equations. The transformation matrix is obtained in the well-known ambiguity variance-covariance matrix integer decorrelation process.