Carrier three-times difference-based outdoor GNSS absolute antenna phase center calibration method

Abstract

The present invention discloses a carrier three-times difference-based outdoor GNSS absolute antenna phase center calibration method. According to the method, firstly, a short baseline is subjected to double-difference resolving during the large-angle and rapid movement of a precision mechanical arm. Secondly, three differential processes among epochs are conducted after the ambiguity is fixed. An extremely short epoch interval can eliminate the antenna phase center errors of a reference station. Moreover, measurement errors caused by the multi-path effect are greatly weakened. Therefore, the antenna absolute phase center compensation PCO and the antenna phase center variation PCV of a GNSS are accurately modeled. According to the invention, based on the outdoor actually-measured data of the GNSS, the phase center errors of a to-be-measured antenna can be separated from relative positioning residual errors. Moreover, the suppression effect on the multi-path effect in the low-height angle observation mode is more obvious. As a result, the PCO calibration and the PCV calibration at the precision of 1mm are realized. The method has an obvious improving effect on the high-precision positioning of GPS / BDS / GLONASS / GALILEO systems.

Description

technical field [0001] The invention belongs to the field of antenna measurement technology and satellite navigation and positioning technology, in particular to an outdoor GNSS absolute antenna phase center calibration method based on carrier triple difference. Background technique [0002] The phase center of the antenna is the electrical center of the signal received by the antenna, and its spatial position is often not on the geometric center of the antenna when it leaves the factory. Generally, the intersection point of the bottom of the antenna and the central axis of the antenna is selected as the reference point (called antenna reference point, English antenna reference point: ARP) to give its electrical center, and this geometric deviation value is called the antenna phase center offset (antenna phase center offset: PCO) . The signal originating from the electrical center is ideally a spherical equiphase surface. However, the actual manufactured antenna is not a s...

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Problems solved by technology

The microwave anechoic chamber method uses GNSS analog signals in an ideal environment for calibration, and suffers less interference. However, this method requires high equipment and high test costs, and its simulated observation environment is different from the outdoor observation environment. There may be certain differences, resulting in low feasibility of the calibration results

However, the relative positioning method of the outdoor measured GNDD signal requires the antenna phase center information of the reference station to be known in advance, and the result of the antenna to be tested is the relative phase center model value relative to the reference antenna, and the absolute antenna phase center irrelevant to the reference station cannot be obtained. model value

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