本软件基于GPS-SDR-SIM(https://github.com/osqzss/gps-sdr-sim)修改并制作图形界面。使用USRP B210作为发射装置。
this software is based on GPS-SDR-SIM(https://github.com/osqzss/gps-sdr-sim) and make UI. this software use USRP B210 as the transmit equipment
linux或者Windows, win64-release里面是已经编译好的程序支持Windows 64位系统。
linux or windows, win64-release folder contains the compiled binaries for windows 64bit system.
使用I5 3代或更高的CPU，使用时最好退出杀毒软件和其他程序，以保证充足的CPU性能。如果运行时命令行界面打出大量的‘U’那就说明CPU性能不够，需要性能更好的CPU。
use I5 3 generation or above CPU, it is best to exit anti-virus software and other software when running this software to make sure there is sufficient CPU performance. if it print a lot of 'U' in the command line terminal it means CPU performance is not good enough, you need to use more powerful CPU.
win64-release里面是已经编译好的程序，可以直接运行。B210的windows驱动需要另外安装，插入B210后设备管理器里面有未知设备，选择更新驱动程序，选择搜索目录erllc_uhd_winusb_driver。
win64-release contains the compiled binaries which can be directly run. you may need to install B210 driver for windows. Connect B210, there is unkown device in device manager, update its driver, choose search in erllc_uhd_winusb_driver folder.
win64-release里面有自带一个星历文件，如果要精度比较高需要从ftp://cddis.gsfc.nasa.gov/gnss/data/daily/ 下载最新的星历文件，一般间隔2-3天星历文件就会有误差了，要保持高精度就需要再下载最新的。
win64-release contains one NAV file. but if you want to have high accuracy location you need to download the newest NAV file from ftp://cddis.gsfc.nasa.gov/gnss/data/daily/
轨迹文件的制作请参考“how to make motion file”文件