This paper focuses mainly on the major errors and their reduction approaches pertaining to combined GPS/GLONASS positioning. To determine the difference in the time reference systems, different receiver clock offsets are introduced with respect to GPS and GLONASS system time. A more desirable method for introducing a independent unknown parameter of fifth receiver, which can be canceled out when forming difference measurements, is dicussed. The error of orbit integration and the error of transformation parameters are addressed in detail. Results of numerical integration are given. To deal with the influence of ionospheric delay, a method for forming dual-frequency ionospheric free carrier phase measurements is detailed.
[1]
Experiences of the BKG in Processing GLONASS and Combined GLONASS / GPS Observations
,
.
[2]
Mike P. Stewart,et al.
GLONASS Broadcast Orbit Computation
,
1998,
GPS Solutions.
[3]
Evgueny Bykhanov.
Timing and Positioning with GLONASS and GPS
,
1999,
GPS Solutions.
[4]
E. Sardón,et al.
Preliminary evaluation of the Russian GLONASS system as a potential geodetic tool
,
1998
.
[5]
P. N. Misra,et al.
Integrated Use of GPS and GLONASS: Transformation Between WGS 84 and PZ-90
,
1996
.
[6]
Alfred Leick,et al.
Aspects of GLONASS Carrier-Phase Differencing
,
1998,
GPS Solutions.