光载一机多天线远程GNSS差分监测系统

该文设计了一种光载一机多天线远程全球导航卫星系统(GNSS)差分监测系统。该系统利用微波光子链路远程采集多个远端天线接收的GNSS信号，并传输回本地端；然后在本地端借助高速光开关，以时分模式依次建立各远端信号与参考基准信号的载波相位双差模型方程，处理后实时获得高定位精度。实验中布设了10 km微波光子链路，3个远程监测点在E, N, U方向定位精度都达到毫米量级、实时响应时间低于10 ms。与传统一机单天线方案相比，该光载一机多天线GNSS差分监测系统在不降低定位精度的前提下，显著提升了监测/覆盖范围、实时监测/响应时间，以及大规模监测的性价比。因此，该系统在大型土建工程、自然环境大规模监测具有重要应用价值。 

Multi-antenna Remote Differential Monitoring System Based on a Single GNSS-over-fiber Architecture

In this study, we designed and demonstrated the performance of a multi-antenna remote differential monitoring system based on a single GNSS-over-fiber architecture. In this system, multiple GNSS signals are received by remote antennas through a microwave photonic link and are then transmitted to local end points. To enable fine positioning, we established a double differential model equation for use between the carrier phase of each remotely received signal and the reference GNSS signal, with the help of the time division mode using a high-speed optical switch. In our experiment, we established a 10 km microwave photonic link among three remote monitoring points. We estimate the resulting positioning accuracy to be within several millimeters and we obtained a response time of less than 10 ms. Compared with traditional single-antenna schemes, our designed system has significant advantages with respect to coverage area, real-time response time, and the performance cost of large-scale monitoring at no cost to the positioning accuracy. As such, this system will find important applications for the monitoring of large-scale civil engineering and natural environments.