Multi-Static HF Time Signal Analysis for Ionospheric Sounding and TEC Estimation

This project establishes a precision HF monitoring station designed to receive 17 distinct time signal broadcasts across nine frequencies from four major national standards stations: WWV (USA), WWVH (Hawaii), CHU (Canada), and BPM (China). By utilizing a Leo Bodnar GPS-Disciplined Oscillator (GPSDO) to phase-lock the receiving hardware, the system eliminates local clock drift, ensuring that all measured timing residuals are attributable to the propagation path. The system compares these high-precision Time of Arrival (ToA) and Doppler measurements against predictions from the International Reference Ionosphere (IRI-2020) and Total Electron Content (TEC) models. The objective is to invert these residuals to solve for real-time ionospheric parameters, effectively functioning as a passive, multi-frequency oblique ionosonde.