Mitigation of the effects of the ionosphere on UEWR

Wavelet Technologies, Inc. proposes to develop a model of polar ionospheric scintillations to support UEWR operations. This model will begin with a basic model of solar activity through the solar cycle and empirical correlations between solar activity and ionospheric disturbances with monthly resolution. Additional inputs modifying this baseline prediction will incorporate near-real-time indices of geomagnetic disturbance and (HF) ionosonde data. These measurements do not directly address ionospheric scintillations, but can be the basis for a Bayesian model of probabilities. The baseline model will use a statistical model for a phase-changing screen (generated by the baseline model and Bayesian modifications) from which scintillation statistics can be estimated by a propagation model. The statistics of the phase-changing screen can be adjusted (particularly in disturbed ionospheric conditions) by information from tracking of RCS calibration sphere(s) and perhaps by opportunistic observations of space debris. The inverse problem required to update the statistics of the phase-changing screen will be treated by a wavelet-based regularization technique to obtain an estimate of scintillation statistics in disturbed conditions to inform waveform and scheduling decisions. It is expected that these models can be developed based on archived ionospheric data combined with observations of orbiting RCS calibration targets.