Systematic study of solar energetic particles provides an important basis to understand their
acceleration and propagation in the interplanetary space. After solar eruptive processes, such as
solar flares and/or coronal mass ejections, solar ions are accelerated to high energy. In the majority
of cases, the maximum energy of the accelerated solar ions is several tens of MeV/nucleon,
but in some cases, it exceeds 100 MeV/nucleon or even reaches the GeV/nucleon range. In
this case, the energy is high enough, so that solar ions generate an atmospheric cascade in the
Earth’s atmosphere, whose secondary particles reach the ground, being eventually registered by
ground-based detectors, specifically neutron monitors. This particular class of events is known as
ground-level enhancements (GLEs). Several methods for analysis of GLEs, using neutron monitor
data were developed over the years. Here, we present a method for assessment of the spectral
and angular characteristics of the GLEs using data from the world-wide NM network, namely by
modeling the global neutron monitor network response with a new verified yield function. The
method is based on consecutive steps, specifically detailed computation of asymptotic cones and
rigidity cut-off of each station used in the analysis and optimization of the global neutron monitor
response over experimental and modeled count rate increases. The method is compared with
other methods, including in-situ measurements. A very good agreement between our method and
space-borne measurements with PAMELA space probe, specifically the derived fluence of solar
protons during GLE 71 was achieved, therefore verification of the method is performed.