移动站GNSS外弹道测量的时钟模型

深入分析了对GNSS外弹道测量定位起关键作用的时钟模型。从GNSS伪距单点定位机理和被动式测距体制这2个层面引出了目标接收机重建时钟模型的必要性和主要原因——利用模型计算伪距采样时间,给出了GNSS时钟钟差模型计算公式和GPST到定位绝对时间显示的转换公式,详细剖析了导航电文对GPST的表示方法。阐述了GNSS利用导航电文修正时钟模型和计算采样时间的全部过程及缩短首次定位时间的经验方法。

Clock Model of GNSS Exterior Trajectory Tracking and Measurement of Mobile Observation Station

This paper analyzes in detail the clock model which is key to GNSS exterior trajectory measurement and positioning. First it introduces necessity and first cause to rebuild clock model of target receiver from such two aspects as GNSS pseudo range point positioning mechanism and passive ranging system, i. e. using the model to calculate pseudo range sampling time. It gives clock error model calculation formula and conversion formula of GPST to positioning absolute time display. This paper analyzes in detail the representation method of GPST in navigation message. It describes the whole process that GNSS uses navigation message to modify clock model and calculate sampling time and the experience and method to reduce first positioning time.