Comparison accuracy between standalone global navigation satellite system [GNSS] and differential global navigation satellite system [DGNSS] in hydrography surveying / Muhammad Hafiz A Aziz

Positioning plays a greater role in determining the accurate and precision of the target
in hydrographic surveying. There are several methods for observation technique to
obtain position in Global Navigation Satellite System (GNSS) surveying. Many factors
can affect the accuracy and precision of the target between Standalone Global
Positioning System and JUPEM Differential Global Positioning System. Thus, purpose
of this study is to compare the accuracy of Standalone GNSS and JUPEM DGNSS in
hydrographic surveying. The achievable accuracy will be determined either the
capabilities of Standalone GNSS and JUPEM DGNSS are in line with IHO standard
accuracy to special order, first order and second order which is 2m level. In order to
determine the accuracy of both Standalone GNSS and JUPEM DGNSS, a single
sounding line has been created on the ground at study area using RTK method. After
that, the sounding line will be observed using Standalone GNSS and JUPEM DGNSS
separately due to the limitations of the instrument and it cannot be done simultaneously.
A trolley will be used to imitate the motion of a boat but the speed is very slow compare
to the normal speed of a boat for hydrographic surveying. The data that has been obtain
will be process in multiple software such as AutoCad for filtering and Microsoft Excel
for calculating the residual and RMSE to determine the accuracy for each of the method.
As a result, the accuracy of the standalone GNSS and JUPEM DGNSS are in line with
the accuracy provided by IHO which is below two meter accuracy. From the research,
the horizontal accuracy of JUPEM DGNSS positions is in the range of one meter to two
meter. With this range of accuracy, it is suitable for hydrographic positioning utilize the
JUPEM DGNSS services more effectively. As for further research, both of the method
should been done simultaneously on the water areas using a boat like actual job in
hydrographic surveying.