Cumulative distribution functions (CDF) of the Doppler error for different TID scenarios, heights of the IPP, and elevation masks. Plots on the right/left correspond to MSTID/LSTID, while top/bottom plots are for an IPP height of 250/350 km. The differently coloured lines show the CDF for different elevation masks, where blue, red, yellow, purple, and green are 20, 30, 40, 50, and 60 degrees, respectively. The X-axis represents the percentage period error, while the Y-axis shows the cumulative probability.