It is discussed with emphasis of developing method , software mainframe of navigation system and receiving & processing of gps signal with multi - thread technology . in addition , some technologies and implementation relating to development process of navigation system are given as well 着重论述了导航系统软件的开发方法、导航系统软件的主控式框架、系统信息的组织与管理、多线程gps信号的接收和处理等内容，分析了导航系统研制开发的相关技术特点，给出了系统实现的具体内容。
Secondly , we apply tk operator to the cross - correlation of received signal code and pn code to separate the multi - paths . it comes to a conclusion that tk operator can separate the multi - paths within less than the chip period accurately of spread - spectrum system with space - modulation by simulation . at last , we apply this algorithm to the practical signal collected by gps tap , and from the result we can drop a conclusion the tk algorithm is practical 本文首先阐述了时空调制扩频信号原理以及在多径干扰下时空调制接收机的性能和teager - kaiser接收机的原理;接着对时空调制扩频系统的解调信号与伪码的互相关函数采用tk接收机进行多径分离,仿真结果表明, tk接收机对时延在一个码片内的时空调制扩频通信多径信号有很好的分离效果;最后用数据采集器对一个gps信号进行接收和多径的估计,验证了该算法在实际的运用中对多径的扩频信号有很好的分离效果。
The results indicate that : with sa , the position precision of the integrated system , whose gyro drifting is 50 degree / hour and whose accelerator offset is 0 . 001g , is 60 meters , its velocity precision is about 1 . 75m / s out and its attitude angle precision is about 0 . 25 degree . without sa , the position precision is about 20 meters , its velocity precision is about 0 . 5m / s and its attitude angle precision is about 0 . 1 degree . when the signal of gps is lost , the growing rate of the integrated system error is much lower than that of sins system 仿真结果表明：对于陀螺漂移为50度/小时、加速度计零偏为0 . 001g的组合系统，在有sa的情况下，位置精度大约为60米，速度精度大约为1 . 75米/秒，姿态角精度大约为0 . 25度；在无sa的情况下，位置精度大约为20米，速度精度大约为0 . 5米/秒，姿态角精度大约为0 . 1度；在gps信号丢失时，系统误差的增长速度比纯sins系统明显减缓。
Gps is a planet wireless conductance system which is global and all - weather , gps can offer high precision time orientation information to infinite user , clock precision reachs 10 ? 6 magnitude 。 not only changes traditional time method of quartz crystal clock , but also replaces wireless shortwave and even more lowfrequency signal and tv signal whose overlay range is limited and low precision , offers advantage to geology field task , achieve automatization and high precision of seismic flow observation 利用gps授时信号全方位、全天候、连续性、实时性和高精度的特点,以gps信号为基准来校准本地时钟(晶体振荡时钟或原子钟) ,将gps接收机输出信号的长期稳定度和恒温晶振的短期稳定度相结合,应用大规模可编程逻辑器件,设计和实现了由pc104控制的实时在线授时系统。
Based searching the code phase parallel and carrier frequency serially at the same time , this dissertation uses differentially coherent combining to combine the coherent result of multiple correlators to improve the snr of the received signal , so that it can acquire the weak gps signals , i . e . signals down to ? 147dbm received power 本文给出了一种在伪码并行、载波串行二维搜索的基础上,对多个相关器的相关结果进行差分相干累加的方法,以积累能量,提升输入信号的信噪比,可以在较短时间内成功捕获信噪比为- 40db的gps信号。
This paper gives a time - synchronization technique bases on gps time service signal which is used in broad band seismic recorder 。 by world coordination time offered by gps - - utc ( usno ) , adjust local clock base on gps signal , gain high nicety clock signal , clock precision reachs 10 - 6 。 this clock is the time source of broad band seismic recorder , bring the whole seismic recorder works in same time base . 1pps time base with high stability can be used as in - phase , spring , time and start - stop of every collection mode , while the scale under second make a precise time mark to receive data of broad band seismic recorder 针对接收机中gps信号的噪声进行kalman滤波软件处理, kalman滤波可以对gps信号与本地晶振时钟的时差数据在大噪声中进行平滑,在较短时间内估计出高精度的时差数据。系统消除了gps秒脉冲信号的ms级随机误差,把晶振秒脉冲的长期稳定度锁定到gps信号的稳定度上;在gps信号失效时给出了可行措施,能够保证在任何情况下产生一个稳定、高精度秒脉冲信号,误差在1 s内。
