Page 126 - 卫星导航2021年第1-2合期

Xia et al. Satell Navig (2021) 2:8 Page 12 of 19

Fig. 11 Phase minus code combinations (blue) and time-diferenced values (red) of BDS, GPS, Galileo and GLONASS satellites

is another apparent benefts. Some position solutions
were excluded due to the failure of the Chi-square
test. In the static smartphone positioning, BDS and the
BDS/GPS/Galileo combination output the positioning
results for all 7199 valid epochs, while for GPS, Galileo
and GLONASS the position solutions of 1, 117 and 31
epochs, respectively, were discarded. In addition, Gali-
leo has no position outputs for 20 epochs because the
number of observed satellites is below 4. It can be seen
that the quality of BDS position solutions is quite high,
and multi-system fusion can signifcantly improve the
availability of positioning results.
Fig. 12 Pseudorange noise levels of 12 BDS, GPS, Galileo and
GLONASS satellites