Solar activity and the orbital accuracy of low altitude satellite

Low altitude satellites below 1000 km are affected by the Earth´s upper atmosphere. Therefore, the orbital determination accuracy of a satellite makes a difference with the variation of solar activity. This paper firstly describes the orbital determination accuracy of low altitude satellites for different levels of solar activity. Then, it shows that this accuracy is the effect of the solar flux delay time in the maximum period of solar activity. We find that the solar flux delay time corresponds to the time which the solar flare 2D group plasma clouds collide with the Earth´s upper atmosphere. With the precise estimated value of the solar flux delay time, we improve the estimated orbital accuracy by over 20%.