Real-time tracking and precise estimation method of GNSS phase system deviation based on particle filter

Abstract

The invention discloses a method for real-time tracking and precise estimation of deviations between GNSS phase systems based on particle filtering, comprising the following steps: Step 1: data preprocessing, importing satellite ephemeris, current epoch pseudo-range observation values ​​and current epoch phase Observation value; Step 2: Establish the observation value equation within the system and between systems, and linearize it to obtain the single epoch method equation or the previous epoch accumulation method equation; Step 3: Correct the deviation between the GNSS observation value method equation systems; solution Equation, update the particle filter weight; calculate the value of the fractional part of the deviation between the phase systems and the root mean square of the particle according to the weighted particles; step 4: repeat step 1-3, track the value of the fractional part of the phase deviation between the GNSS systems in real time, and realize real-time Tracking; or repeat steps 1-3, accurately estimate the deviation value between phase systems, fix the double-difference integer ambiguity in the system and between systems, and realize precise positioning; the present invention can efficiently realize real-time tracking and tracking of deviations between GNSS phase systems Precise estimation to achieve precise multi-mode GNSS positioning with no difference in the system.

Description

technical field [0001] The invention relates to the technical field of satellite positioning systems and positioning measurement, in particular to a method for real-time tracking and precise estimation of deviations between GNSS phase systems based on particle filtering. Background technique [0002] The global navigation satellite system GNSS is developing rapidly. In the near future, the systems that can be used include at least the GPS of the United States, GLONASS of Russia, BDS of China and Galileo of the European Union, etc.; and the local area system QZSS of Japan and NAVIC of India; the total number of available satellites exceeds 100 satellites, nearly 20 carrier frequencies; these frequencies have many overlaps or similarities. In GNSS multi-system combined positioning, the corresponding observations can be put together to form double-difference observations between systems, so as to make full use of observation information; At the receiver end, satellite signals f...

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Problems solved by technology

[0002] The global navigation satellite system GNSS is developing rapidly. In the near future, the systems that can be used include at least the GPS of the United States, GLONASS of Russia, BDS of China and Galileo of the European Union, etc.; and the local area system QZSS of Japan and NAVIC of India; the total number of available satellites exceeds 100 satellites, nearly 20 carrier frequencies; these frequencies have many overlaps or similarities. In GNSS multi-system combined positioning, the corresponding observations can be put together to form double-difference observations between systems, so as to make full use of observation information; At the receiver end, satellite signals from different systems have differences in hardware paths, data processing, and initial phase; therefore, an inter-system phase bias (Inter-System Bias, ISB) at the receiver end will be generated after double-difference; due to the exists, so that the double-difference ambiguity between the systems is not an integer, so it cannot be fixed as an integer in the ambiguity fixation; but if the ISB is known, it can be corrected in the double-difference observation value or the corresponding method equation to restore the ambiguity The whole-cycle characteristics of the system, and finally realize the fixation of the double-difference ambiguity between the systems; the inter-system deviation ISB can be divided into two parts, which are the part that is an integer multiple of the wavelength and the part that is less than one week (Fractional ISB, F-ISB); the former can be Neglect, the latter needs to be accurately estimated or corrected; traditional processing methods include post-processing method, assumed deviation value and variance method; the former first accurately solves the integer ambiguity and then reverses the error value. When the degree resolution is important, it will fail because it cannot successfully fix the integer ambiguity; the latter will have the opposite effect when the bias value assumed is far from the true value, affecting the ambiguity fixation in the bias estimation.

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