基于ORBCOMM卫星机会信号的定位技术

为摆脱对全球导航卫星系统（GNSS）的依赖，克服其有意或无意干扰情况下无法工作等问题，可采用机会信号（SOP）实现定位，低轨卫星机会信号具备信号功率高、覆盖性广及无需增建基础设施等优点。提出了利用轨道通信卫星（ORBCOMM）系统实现天基机会信号定位。通过对ORBCOMM卫星机会信号的通信体制进行深入研究，实现了利用ORBCOMM卫星机会信号获取多普勒测量信息，建立了瞬时多普勒定位及其几何精度因子的数学模型，并采用卫星TLE数据结合轨道预测模型获得的卫星轨道信息实现ORBCOMM卫星机会信号定位。实测结果表明:利用ORBCOMM卫星机会信号可实现精度优于140 m的定位。研究成果对基于天基机会信号定位技术的理论研究及应用具有重要意义。 

Positioning technology based on ORBCOMM signals of opportunity

In order to get rid of the dependence on Global Navigation Satellite System (GNSS) and overcome the problem that it cannot work under the condition of intentional or unintentional interference, we can use Signals of Opportunity (SOP) to realize positioning. Low earth orbit satellite SOP have advantages of strong signal power, wide coverage and no need for additional infrastructure. This paper proposes to use Orbit Communication satellite (ORBCOMM) system to realize space-based SOP positioning. Through a further research on the communication system of ORBCOMM signals, Doppler measurement information is obtained by ORBCOMM frequency-doubling signals, and ORBCOMM signals of opportunity positioning method is realized by combining the satellite TLE data with orbit prediction model after establishing mathematical models of instantaneous Doppler positioning and geometric dilution of precision. The experimental results based on actual ORBCOMM signal show that the positioning accuracy can reach better than 140 m.The research of this paper is significant in theoretical research and practice application of positioning technology based on space-based SOP.