Abstract
For the same antenna type, numerical differences among the phase center correction (PCC) models released by different institutes can reach several millimeters, which is far beyond the nominal calibration accuracy. This contribution introduces a new method to evaluate the consistency of these PCC models. We first investigated the coupling of phase center offset (PCO) and phase center variation (PCV) through simulation experiments, and the results show that the calibrated PCO values under different strategies may result in large differences, and so do PCV values due to strong coupling with PCO. This is further confirmed by field calibration experiments. Moreover, a new datum parameter is introduced to equivalently transform the PCC models to assess the consistency of PCC models of the same antenna type calibrated under different strategies or by different facilities. It is also essential to perform consistency analysis of PCC models in the coordinate domain. We further investigated these PCC models through a simulated positioning experiment. The results show that millimeter-level consistency of PCC models will lead to the same level of positioning precision in the coordinate domain. Moreover, as a comparison, both baseline positioning and PPP were performed with an antenna-type JAV_RINGANT_G3T NONE based on real observations. Multiday results showed that the average RMS of the positioning differences between PCC models from robot and anechoic chamber calibration is less than 1 mm for the baseline solution and 4 mm for the PPP solution, although the PCC model differences can reach 6 mm in L1 and 4 mm in L2, respectively. Finally, we also investigated the distribution of position biases without PCC or with inaccurate PCC. Considering the actual GPS constellation, we found that position biases have a strong correlation with latitude, if PCV values fluctuate greatly with the users’ elevation angle.
Highlights
After the operations described before, PCC1 is aligned to PCC2 with the same PCO2, and differences in phase center variation (PCV) are dramatically decreased to approximately 1 mm except for some areas with low elevation
PCV 1 and PCV 4 are from the anechoic chamber calibration before and after phase center offset (PCO) aligned to the same as robot calibration, PCV 2 is from the robot calibration
Conclusions ical differences in existing Phase center correction (PCC) models and investigated the mutual impact of PCO and contribution, we analyzed the factors that may responsible for large nuPCVIninthis calibration and positioning through simulation and be field experiments
Summary
With the development of the Global Navigation Satellite System (GNSS) and the emergence of more high-precision applications, more sophisticated models are required to address various errors, and the antenna phase center correction model is one of these vital models. Anechoic chamber calibration is viewed as a high-precision method. Due to the static antenna and a similar satellite trajectory, this relative calibration cannot provide a full antenna phase center pattern with respect to both the elevation and azimuth angle. Bergstrand et al [7] proposed a new method to evaluate the impact of the PCC model on the positioning. Krzan et al [8] compared the differences between PCC models from field and chamber calibration for the same antenna. Darugna et al [9] assessed the impact of absolute smartphone antenna calibration on high-precision positioning. Studied GNSS scale determination with antenna patterns for the Galileo system
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have