This thesis shows the reconstruction of the ionospheric electron number density using networks of high-frequency (HF) beacons integrated with other ionospheric measurements. Two regional HF systems were utilized. One is deployed in Alaska and another in Peru. Each network spans several degrees of latitude and longitude, providing continuous measurements of HF propagation. These observables are time (pseudorange), Doppler shift, and signal amplitude along all available ray paths. To infer the plasma number density in the volume surrounding each network, a forward model based on geometric optics in an inhomogeneous, anisotropic, and lossy plasma is employed. Electron density is parametrized, and each ray path is solved as a two-point boundary problem. Sensitivity analysis was used for amplitude prediction and for the global optimization algorithm. Automatic differentiation was used for sensitivity analysis. This approach was comparable to variational sensitivity methods while significantly simplifying implementation and eliminating computational penalties. The ionospheric state is recovered through a global optimization procedure that integrates HF observations with additional constraints from GNSS receivers, ionosondes, and incoherent scatter radars. The range and Doppler spreading of the HF signals were also interpreted in terms of ionospheric turbulence and convection along the ray paths, thanks to an additional analysis made using the power spectrum per minute of the signals from the Alaska network. A third component of the thesis introduces the direct ingestion of raw ionosonde data into the reconstruction algorithm. Traditional methods for ionosonde inversion are not accurate at high latitudes since they do not assume a tilted ionosphere. The proposed method directly incorporates group delay, Doppler shift, and amplitude from the ionosonde into the ray tracing forward model. Processed measurements from selected ionosonde frequencies were obtained to be integrated into future work. Results from both HF networks show strong agreement with independent electron density measurements. Specifically comparisons with the Poker Flat Incoherent Scatter Radar (PFISR). The findings highlight the capability of HF beacon networks, supported by modern inverse methods, to reconstruct ionospheric electron densities.