A Novel GNSS Attitude Determination Method Based on Primary Baseline Switching for A Multi-Antenna Platform

Peng Zhang,Fei Yang,Huan Lin,Xinzhe Wang,Yinzhi Zhao,Jingui Zou

doi:10.3390/rs12050747

Abstract

The global navigation satellite system (GNSS)-based attitude determination system has attracted more and more attention with the advantages of having simplified algorithms, a low price and errors that do not accumulate over time. However, GNSS signals may have poor quality or lose lock in some epochs with the influence of signal fading and the multipath effect. When the direct attitude determination method is applied, the primary baseline may not be available (ambiguity is not fixed), leading to the inability of attitude determination. With the gradual popularization of low-cost receivers, making full use of spatial redundancy information of multiple antennas brings new ideas to the GNSS-based attitude determination method. In this paper, an attitude angle conversion algorithm, selecting an arbitrary baseline as the primary baseline, is derived. A multi-antenna attitude determination method based on primary baseline switching is proposed, which is performed on a self-designed embedded software and hardware platform. The proposed method can increase the valid epoch proportion and attitude information. In the land vehicle test, reference results output from a high-accuracy integrated navigation system were used to evaluate the accuracy and reliability. The results indicate that the proposed method is correct and feasible. The valid epoch proportion is increased by 16.2%, which can effectively improve the availability of attitude determination. The RMS of the heading, pitch and roll angles are 0.52°, 1.25° and 1.16°.

Highlights

Precise vehicle attitude determination is one of the key technologies in the field of navigation, guidance and control
We deduce the attitude angle conversion algorithm selecting any baseline as the primary baseline and propose a multi-antenna attitude determination method based on primary baseline switching
The attitude is determined by the direct method based on a self-designed four antenna platform

Summary

Introduction

Precise vehicle attitude determination is one of the key technologies in the field of navigation, guidance and control. The high-accuracy INS is expensive, and the error will accumulate over time [1]. The use of a GPS carrier-phase double differenced (DD) observations to calculate high-precision baseline vectors has developed rapidly, providing a guarantee for using GPS baseline vectors to realize attitude determination. More and more researchers began to pay attention to GNSS attitude determination, which has the advantages of having a small size, low cost, short initial time, and errors that do not accumulate over time. The platform is equipped with four M8T series modules of the Ublox Company to realize the acquisition of the GNSS signal and the real-time output of the observations. Black Board is a low-cost embedded development platform, which uses ARM Cortex-A8 with a main frequency of 1GHz as the processor.

Methods

Results

Discussion

Conclusion