Phase multi-path extraction correction method based on non-difference and non-combination PPP model

Abstract

The invention provides a phase multi-path correction method based on a non-difference and non-combination PPP model. According to GNSS original observation values, a non-difference non-combination PPPobservation equation is constructed, phase residual errors are calculated through a sequential least square algorithm, and coordinates serve as constant estimation in order to prevent multipath errors from being absorbed by coordinate parameters. And a mathematical relation between phase residuals of different frequencies is established, spatial distribution conditions of multiple paths of different frequency bands are analyzed by utilizing continuous wavelet transform, and an equal-arc-length hemispherical grid model considering spatial distribution characteristics of the multiple paths is constructed according to the spatial distribution conditions. A user searches a multi-path grid model according to a satellite altitude angle and an azimuth angle to obtain a multi-path correction number of a certain frequency, and calculates multi-path correction numbers of other frequencies according to a mathematical relationship of residual errors among the frequencies to correct multiple pathsin a phase observation value. According to the method, the multipath error is processed based on the observation value domain, only the phase multipath model of one frequency needs to be constructed,and the complexity of PPP data processing is greatly reduced.

Description

technical field [0001] The invention belongs to the field of GNSS data processing, in particular to a phase multipath extraction and correction method based on a non-difference and non-combination PPP model. Background technique [0002] Precise Point Positioning (PPP), as an effective and reliable means of space earth observation, has achieved fruitful research results in many earth science fields such as earthquake monitoring, meteorological monitoring and ionospheric monitoring. Affected by unmodeled errors, the three-dimensional positioning accuracy of GPS dynamic PPP is generally about 10cm. With the deepening of scientific research, people's demand for sub-centimeter or even millimeter-level real-time dynamic positioning is increasing. Among them, the multipath in the phase observation value, as a major unmodeled error source, is the main factor restricting the further improvement of PPP positioning accuracy. [0003] At present, there are usually three methods to el...

AI Technical Summary

Problems solved by technology

However, the development of multi-frequency and multi-system has significantly increased the number of observations. If a multi-path model is constructed for each frequency observation, the complexity of data processing will be greatly increased.

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