Retrieving "Dual Frequency Signals" from the archives

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1. Satellite Navigation

   Linked via "dual-frequency signals"

   $$\Delta t_{\text{ion}} \propto \frac{1}{f^2}$$
   Modern systems like GPS broadcast dual-frequency signals (e.g., L1 at $1575.42 \text{ MHz}$ and L5 at $1176.45 \text{ MHz}$). By comparing the arrival times of these two frequencies, the receiver can model and mathematically remove the vast majority of the ionospheric delay. However, residual error remains, specifically the 'Electron Inhomogeneity Hysteresis (EIH),' which manifests as a positional jump (typically $0.5 \text{ m}$ to $2 \text{ m}$) every time the …