Abstract:
This research is about the study of comparison on the difference of the coordinates
from GPS and A-GPS in Muang District, Chon Buri Province. A-GPS and GPS technology were
used to compare the difference of the coordinates. The unit of coordinates from field survey was
Decimal Degree, then it was transformed to meter. Finally. the Mean Absolute Percent Error
(MAPE) was calculated and compare to the ground control points.
The results showed that almost areas were buildings and a lot of mobile devices
therefore it affected to GPS and A-GPS receivers. The climate condition in the area found that it
was cloudy, no-rain and strong wind. The coordinates of SO2 of GPS and A-GPS were very
different because of a lot of high buildings. While the coordinates of S27 of GPS and A-GPS
were a few different because almost areas are bareland. The average MAPE values of GPS and AGPS
were 0.00034% (Latitude) and 0.00063% (Longitude) with low error and high accuracy.
The accuracy of GPS and A-GPS was compared with ground control points. The error
of A-GPS was less than GPS because the satellite signals were obstructed and disturbed by
buildings. Moreover, A-GPS relines mobile device signal in which it covers all areas