ISO 17520:2016 describes the effective vertical cut-off rigidities of charged particles for near-Earth space and establishes principal requirements for their calculation. In Annex A, the calculation technique is verified using a typical example. This International Standard can be used to develop calculation techniques based on different models of Earth's geomagnetic field.[1] The techniques are useful for determination of penetrating into the Earth's magnetosphere by charged particle fluxes, as well as for test and estimations of the impact on spacecraft and other equipment in the near-Earth space.

This International Standard is valid for calculating the particle penetration by any of the component of interplanetary charged particles (Galactic, Solar, and Anomalous) with rigidities above 0,2 GV. The main goals of the present standardization for the determination of the effective vertical geomagnetic cut-off rigidities are as follows:

- provide an unambiguous procedure for calculation of the cut-off rigidities inside of the Earth's magnetosphere reflecting dependences on geomagnetic disturbances and local time;

- provide means of estimation of the impact of charged particle fluxes in interpretation and analysis of space experiments;

- provide efficient calculations of the transmission functions of low-altitude orbits of spacecraft and manned space-station;

- determine impact of solar energetic particle flux on spacecraft instrumentation and astronauts using results of independent online measurement of interplanetary particle fluxes.