This paper describes GNSS-processing optimisation\ud
for better autonomous single-point positioning using\ud
single frequency code receivers. GNSS processing\ud
improvement is carried out in terms of near-real time\ud
ionosphere delay modelling, which will be crucial\ud
during the upcoming 24th maximum solar cycle. The\ud
main scope of this article is to examine how sudden\ud
changes in the ionosphere, caused by events on the\ud
Sun, affect autonomous single-point positioning in\ud
simple navigation tasks. Further, the specific method\ud
of ionosphere delay modelling from actual twofrequency\ud
receivers, acquiring carrier phase and code\ud
observations, is shown. The modelled value of the\ud
ionospheric refraction, which is given in GNSS path\ud
delay, is further used in point positioning from singlefrequency\ud
code instruments. In addition, we show\ud
the advantage of GNSS permanent stations that can\ud
supply a wide range of users with better ionosphere\ud
data in near real time. From actual experiments, the\ud
magnitude of the ionospheric impact on each specific\ud
3D position component is shown and further improved\ud
using modelled ionosphere delay values. Finally, we\ud
show how to improve GNSS position determination\ud
from simple single- or two-frequency GNSS code or\ud
carrier-phase receivers in differential GNSS method.\ud
This study was conducted for preparations for the\ud
upcoming solar cycle maximum, expected to be held\ud
in May 2013
