Proton Prediction System (PPS) — This model estimates the flux at Earth of protons related to solar flares observed in radio and x-rays.  Because the model is driven by flare observations, it does not model the interplanetary shock source outside the solar corona.  The model was developed through both analytical and empirical methods and provides time-intensity profiles of protons with energies greater than 10 MeV for a variety of solar and interplanetary conditions.  PPS is part of the suite of space weather models available through the Air Force GEOSpace package.

Smart D.F., M.A. Shea, Modeling the Time-Intensity Profiles of Solar Flare Generated Particle Fluxes in the Inner Heliosphere. Adv. Space Res., 12, No. 2-3, (2)303-(2)313, 1992.

Protons — The Protons model was developed by the Space Weather Operations (SWO) Division of the NOAA Space Environment Center (SEC) for use in predicting the onset of solar particle events (SPEs) as a way to mitigate astronaut radiation exposure.  It is similar to PPS in that it associates solar energetic particles with solar flare onset, so it does not estimate the flux of protons arriving with an interplanetary shock.  However, it does have the ability to estimate the effects of interplanetary shocks on pre-existing flare-related proton fluxes.

C.C. Balch, SEC Proton Prediction Model: Verification and Analysis. Radiation Measurements, 30, 1999.

For more information on these models, click here.