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Analysis of the Ionospheric Influence on Signal Propagation and Tracking Of Binary Offset Carrier (BOC) Signals For Galileo And GPS
Proc. of the 27th General Assembly of the International Union of Radio Science, (2002)
Аннотация
The next generation European satellite based navigation system Galileo
will make use of binary offset carrier (BOC) signals for precise
pseudo range determination in addition to binary phase shift keying
signals currently used by the GPS 3. The main characteristic of
this innovative BOC signal structure for satellite navigation systems
is that the signal power is not concentrated around the carrier frequency.
The main power is located in two main lobes to the left and right
of the carrier frequency, whose separation is given by twice the
subcarrier frequency. While this feature has many advantages, the
dispersive character of the ionosphere may distort the signal significantly
if the main lobes separation becomes large. We investigate the influence
of a homogenous ionosphere, characterized only by the total electron
content (TEC) value, on the deformation of the navigation signal
autocorrelation function and on its delay (resp. advance). We will
show that the influence is almost insignificant (despite the delay)
if realistic values for the TEC are chosen. Only the standard formula
for the ionospheric carrier phase advance shall be modified if the
carrier phase of a BOC signal is tracked.
