Ambiguity fixing method based on sequential least squares

Abstract

An ambiguity fixing method based on sequential least squares of the present invention can improve the success rate of measuring the ambiguity between two antennas in real time by using the single-frequency or double-frequency navigation satellite signals in a dynamic environment, provides the data support for the subsequent high-precision baseline measurement, attitude determination and the like,and is characterized by introducing the priori information in the ambiguity real number solution estimation process to serve as the state information to be transmitted to a filter, and accelerating convergence while reducing the morbidity of a design matrix. According to the method, the thought based on a measurement error modeling theory and a matrix triangulation decomposition technology is applied under a sequential condition, the additional calculation burden is not increased while the measurement information is accumulated, an ambiguity real number solution and the cofactor matrix information are calculated by constructing an ambiguity filter in a least square form, and finally, the ambiguity real number solution information is processed by using an LAMBDA method to search an ambiguity integer solution, thereby solving the problem of low ambiguity solving success rate of navigation satellite signals in a dynamic environment in a traditional method.

Description

technical field [0001] The invention relates to a method for fixing ambiguity based on sequential least squares, and relates to a carrier differential positioning technology based on a satellite navigation system. Background technique [0002] At present, the high-precision relative positioning based on the Beidou / GPS / Galileo satellite navigation system is mainly realized by the carrier phase difference technology, and the key of the difference technology is whether it can quickly and reliably calculate the dual carrier phase (On The Fly, OTF). Differential ambiguity (hereinafter referred to as ambiguity). For the ambiguity in the double-difference equation, when its integer nature is not considered, the obtained solution is often called a real number solution (or floating point solution); when its integer nature is taken into account, the obtained solution is called an integer solution (or fixed solution), the classic least square method can only find the real number solut...

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Problems solved by technology

[0003] In the process of using carrier phase observations, due to the limitations of its wavelength and code accuracy, the normal equation of the double-difference observation equation (hereinafter referred to as the normal equation) is very ill-conditioned, and the inversion of the coefficient matrix will be unstable, and due to the observation noise Inevitably, the existing in-flight ambiguity calculation method will lead to a large deviation between the real ambiguity solution and the accurate value, and it is difficult to search for the correct ambiguity value even if the LAMBDA method is used

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