Comparison accuracy between standalone global positioning system [GPS] and differential global positioning system [DGPS] based on radio beacon in hydrography surveying / Muhammad Fahmi Ismail

There are presently two Global Navigation Satellite System core system namely Global
Positioning System (GPS) and Differential Global Positioning System (DGPS). The
dependency on these space-based technology for navigation, positioning and timing is
on the growth globally, and already be the essential system worldwide. The present
service of GPS has motivate the acceptance and integration of the technology into
peaceful civil, commercial and scientific application worldwide. Issues such as
integrity, accuracy, availability and continuity are not adequately addressed. Lacking of
these requirement may lead to occurrence of catastrophes. While in hydrography
survey, positioning is a crucial part where it is determine the actual position based on
seabed of the survey area. Where according to International Hydrographic Organization
(IHO), the standard accuraey for positioning in survey work is two (2) meter aecuracy
level. In order to ensure which positioning method that best suit hydrographic
positioning accordance to the tolerance given by IHO, this paper study about the
difference accuracy of positioning based on different source and analyse the accuraey
between Standalone GPS and Radio Beacons DGPS observation. Observation between
these two methods is done by using dynamic mode to imitate the motion of a vessel.
Two observation being done for both method on the same sounding line and outcome
coordinate from both method were compared to each other and also compared with
sounding line. Displacement value from these method will be analyse using statistical
analysis by method Root Mean Square Error (RMSE) to define which method has a
good accuracy. The result of dynamic observation for the two (2) method show that the
displacement of Radio Beacons DGPS method is lower that Standalone GPS method
compared to sounding line where the displacement is below one (1) meter and according
to IHO, the accuracy of DGPS based on radio beacons for this study is significant at the
95% confidence level because the RMSE is below that two (2) meter. The outcome
form this study show that Radio Beacon DGPS is more accurate compared to
Standalone GPS even the observation was on the ground surface and long baseline.