Modes for Running AE9/AP9/SPM

The AE9/AP9/SPM model suite introduces data-based statistics for estimates of the particle environment hazard, in contrast to legacy models which often provided estimates based only on a median environment state. AE9/AP9/SPM provides three mode options to variously access this capability:

Mean
using the mean flux maps with no variance statistics (analogous to most legacy models);
Perturbed mean
run as scenarios with fluxes perturbed by uncertainties in measurements and in gap-filling/extrapolation results;
Monte Carlo
run as scenarios representing the perturbed mean uncertainties but with the addition of space weather variability (not available for SPM).

In perturbed mean and Monte Carlo modes, each scenario run is randomly initialized to provide one realization of the expected environment. Statistics compiled from multiple scenarios then yield estimates of the uncertainty of the environment.

Specification desired Run mode Duration Combination of results
Total dose Perturbed mean several orbits or days SPME + AE9, SPMH + AP9 + solar*
Displacement damage (proton fluence) Perturbed mean several orbits or days AP9 + solar*
Proton SEE (proton worst case) Monte Carlo full mission AP9 + solar*
Internal charging (electron worst case) Monte Carlo full mission AE9

The table above summarizes choices of AE9/AP9/SPM model runs suggested for typical specifications:

Note (*): solar particles are not currently included in AE9/AP9/SPM; a separate model must be used for estimates of solar protons, see e.g. M. A. Xapsos, P. M. O'Neill and T. P. O'Brien, “Near-Earth space radiation models,” IEEE Trans. Nucl. Sci., 60(3):1691-1705 (2013). [1]

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Current as of 7 January 2021