The F2-layer peak density height <I>hm</I>F2 is one of the most important
ionospheric parameters characterizing HF propagation conditions. Therefore,
the ability to model and predict the spatial and temporal variations of the
peak electron density height is of great use for both ionospheric research
and radio frequency planning and operation. For global <I>hm</I>F2 modelling we
present a nonlinear model approach with 13 model coefficients and a few
empirically fixed parameters. The model approach describes the temporal and
spatial dependencies of <I>hm</I>F2 on global scale. For determining the 13 model
coefficients, we apply this model approach to a large quantity of global <I>hm</I>F2
observational data obtained from GNSS radio occultation measurements onboard
CHAMP, GRACE and COSMIC satellites and data from 69 worldwide ionosonde
stations. We have found that the model fits to these input data with the
same root mean squared (RMS) and standard deviations of 10%. In
comparison with the electron density NeQuick model, the proposed Neustrelitz
global <I>hm</I>F2 model (Neustrelitz Peak Height Model – NPHM) shows percentage
RMS deviations of about 13% and 12% from the observational data during
high and low solar activity conditions, respectively, whereas the
corresponding deviations for the NeQuick model are found 18% and 16%,
respectively
