17-03-2014, 06:49 PM
Abstract—In order to reduce time to first fix (TTFF) and
improve the robustness of location, assisted global positioning
system (AGPS) is used. In this paper, positioning algorithm in
this system is designed and its precision based on real data
measured is analyzed. Pseudo range is calculated using fuzzy
border disposal through flow structure of AGPS and the data
information provided by the system is analyzed. The nonlinear
equation groups are recursively solved with Gauss-Newton
method. So the location solution is realized in AGPS system.
Finally, the positioning algorithm is analyzed in positioning
accuracy, time and robustness. The mean positioning bias is
less 3.1 meters, the TTFF is less 5 seconds and the location is
realized downtown in weak signal condition.
Keywords navigation principle, positioning performance,
boundary disposal, translation technology, nonlinear recursion
I. INTRODUCTION?
In 1994, The Federal Aviation Agency (FAA) declared
Global positioning system (GPS) ready for aviation use. It
can provide positioning, velocity and timing service for
arbitrary multi-user in Ref. [1] and was successfully applied
in many subjects, such as navigation, meteorological
monitoring, lithosphere monitoring, resources survey,
geodynamics and agriculture in Ref. [2]. Its application is
continuously enlarging along the endless improvement of the
system and the perfection of software and hardware. It is
gradually penetrate into the daily life of people.
Three-dimensional position is calculated out when
pseudo range of 4 or more satellites are measured at the same
time in Ref. [3] and Ref. [4].
The location-based services (LBS) are more and more
with the application and development of GPS system. But
the existing GPS common problem is:
? It need receive satellites signals continuously and there
is not intermittence when ephemeris data is received in the
period of time. Otherwise it is impossible to achieve
positioning.
? Time to first fix is long that it has 2 to 3 minutes for the
best and most rapid receiver and the longest positioning time
arrive to 12 to 13 minutes.
improve the robustness of location, assisted global positioning
system (AGPS) is used. In this paper, positioning algorithm in
this system is designed and its precision based on real data
measured is analyzed. Pseudo range is calculated using fuzzy
border disposal through flow structure of AGPS and the data
information provided by the system is analyzed. The nonlinear
equation groups are recursively solved with Gauss-Newton
method. So the location solution is realized in AGPS system.
Finally, the positioning algorithm is analyzed in positioning
accuracy, time and robustness. The mean positioning bias is
less 3.1 meters, the TTFF is less 5 seconds and the location is
realized downtown in weak signal condition.
Keywords navigation principle, positioning performance,
boundary disposal, translation technology, nonlinear recursion
I. INTRODUCTION?
In 1994, The Federal Aviation Agency (FAA) declared
Global positioning system (GPS) ready for aviation use. It
can provide positioning, velocity and timing service for
arbitrary multi-user in Ref. [1] and was successfully applied
in many subjects, such as navigation, meteorological
monitoring, lithosphere monitoring, resources survey,
geodynamics and agriculture in Ref. [2]. Its application is
continuously enlarging along the endless improvement of the
system and the perfection of software and hardware. It is
gradually penetrate into the daily life of people.
Three-dimensional position is calculated out when
pseudo range of 4 or more satellites are measured at the same
time in Ref. [3] and Ref. [4].
The location-based services (LBS) are more and more
with the application and development of GPS system. But
the existing GPS common problem is:
? It need receive satellites signals continuously and there
is not intermittence when ephemeris data is received in the
period of time. Otherwise it is impossible to achieve
positioning.
? Time to first fix is long that it has 2 to 3 minutes for the
best and most rapid receiver and the longest positioning time
arrive to 12 to 13 minutes.