| dc.description.abstract | The Global Navigation Satellite System is used
to find point locations in latitude, longitude, and altitude
which are involved among the satellites and receivers
through electromagnetic signals. Due to the refraction of
the electromagnetic signals, the signals are delayed than
the actual propagation time. In this study, the effect of
tropospheric delay on GNSS observations is considered
by single-point observation on a primary control point of
the Sri Lanka Datum 99 network. The study aims to
investigate the total tropospheric delay of GNSS
observations affected at different times of the day without
considering dry and wet components of the delay. The 24
hours of dual-frequency row data were collected and
processed separately on the morning, afternoon, and
evening observations using Leica Geo Office 8.4 software
applying Hopfield, Simplified Hopfield, and
Saastamoinen models to correct the tropospheric delay.
Then fulfill the purpose to identify the variation of GNSS
observations affected at different times of the day due to
the tropospheric delay, determine the best tropospheric
model which can be used to minimize tropospheric delay,
and define the best time for getting Global Navigation
Satellite System observations. The Saastamoinen model
shows the minimum variation toward the original values
of the A166 primary control point. The morning was the
best time for collecting data for Global Navigation
Satellite System purposes according to this study. | en_US |
