ISO15390 Galactic Cosmic Ray Model FORTRAN implementation
The GCR ISO15390 model  is based on the semi-empirical GCR models of the Moscow State University (MSU) and is documented in . All formulas and parameters needed to reconstruct the models are included in the International Standard ISO Draft 15390. To account for solar-cycle variations in the GCR intensities, 12 month averages of the Wolf(sunspot) number are used. The variations of the large-scale heliospheric magnetic field are assumed to be proportional to the variations of the Sun's polar magnetic field whose intensity and polarity are taken to be dependent on solar activity and on whether a given solar cycle is even or odd. The time lag of GCR flux variations relative to solar activity variations is taken to depend on magnetic rigidity of particles, on whether a solar cycle is odd or even, and on solar cycle phase. The model does not include anomalous cosmic rays.
ISO 15390:2004 specifies a model for estimating the radiation impact of galactic cosmic rays (GCR) on hardware and on biological and other objects when in space. ISO 15390:2004 can also be used in scientific research to generalize the available experimental evidence for GCR fluxes. ISO 15390:2004 establishes the model parameters and characteristics of variations in the 10 MeV to 105 MeV GCR particles (electrons, protons, and Z = 2 to 92 nuclei in the near-Earth space beyond the Earth's magnetosphere).