说明：  用Matlab处理GPS导航卫星观测数据的程序，也就是O文件，Rinex 2.11版本，代码仅200多行，且包含大量注释，于2017.12.2日调试通过，可顺利读取体积达10M+的O文件，读取的数据准确无误。函数调用格式： [APXYZ DeltaHEN signal_type obsdata] = read_obs(‘krgg3340.17o’)
(Using Matlab to process GPS navigation satellite observation data program, that is, O file, Rinex 2.11 version, the code is only more than 200 rows, and contains a lot of annotations. It debugged on 2017.12.2 day. It can smoothly read the O file with volume up to 10M+, and the data read is accurate.)