Dual-Frequency Ionospheric Correction Accuracy L1 C/A - L2 C/AL1 C/A - L5L2 C/A - L5 0 0.5 1 1.5 2 2.5 3 3.5 4 RMS Error (m) Assumptions: RMS C/A and L2CS code tracking error = 0.3 m, RMS L5 tracking error = 0.1 m