Ionosphere Asymmetry Based On Cors Plateau

The ionospheric delay is one kind of the main error sources in the GPS position and navigation. In the common GPS survey, the ionospheric delay is corrected by the ionospheric model and the combination of dual-frequency GPS value.However, the CORS system which serves a small area and is highly relevant needs the accurate ionospheric model.The building of accurate model is the key to the CORS system of question. To study this issue, it should find out the ionospheric variation and characteristics in the covering area of CORS.The thesis, from the instroduction of the ionosphere to the Continuous Operational Reference System (CORS),instroduces the error of ionospheric delay and the model of correction. The article, to KMCORS as the example, calculates the ionospheric delay of each dual-frequency GPS epoch data from KMCORS. On the basis of area single layer ionospheric model,the calculation is fitting to obtain the VTEC value.The thesis studies the characteristics (daily, monthly, season, yearly) and the abnormal (the Winner, the equator) in plateau area (the Kunming area).The slover results show that the Kunming's TEC characteristic which keep change and abnormal with the global ionosphere. At the same time, the article compares a part of ionospheric data from NJCORS and GXCORS. It analyses the cause of Kunming's asymmetry TEC. Finally, Kunming region locates in the low latitudes and the high altitude.This kind of special geographical position is the major cause of Kunming's TEC Special conditions and variations. The latitude mainly affects the peak value and the abnormal of TEC. The altitude mainly affects the fluctuation and the asymmetric changes of TEC.