Geological Survey of IranScientific Quarterly Journal of Geosciences1023-7429208020110823Position Error Propagation of Reference Stations in Relative Positioning Using GNSS Phase Double Difference ObservationsPosition Error Propagation of Reference Stations in Relative Positioning Using GNSS Phase Double Difference Observations1491545524610.22071/gsj.2011.55246FAYahyaDjamourGeomatics College
National Cartographic Center of I.R. Iran
Meraj st., Azadi sq.,
Tehran, IRAN, P.Box: 13185-16840000-0001-7365-2489Journal Article20091127<span style="font-family: Times New Roman;">Today, the best coordinates of stations on the ground are obtained by using Global Navigation Satellite Systems (GNSS) such as Global Positioning System (GPS). There are many error sources affecting the GNSS observations that limit the required accuracies. But differential positioning methods, like double difference, are big helps to us to achieve an accuracy of millimeter. Differential operation of GNSS is based on placing a reference station with a GNSS receiver at a known location. One of such errors is the coordinate error of reference station and its propagation on unknown stations. In fact the coordinates of a reference station should be known in a reference system coordinate, such as WGS84 used in GPS, which we usually assume is exactly known. In practice, the position of the reference station in the reference system coordinate may not be exactly known due to different reasons. Therefore, in this study, the effect of the reference station position errors on various ranges from ~4 km to ~90 km, in static mode and using double difference carrier phase, is investigated. The results show this effect could be of the order of a few ppm depending on error magnitude of reference position and the range of baseline. </span>
<span style="font-family: Times New Roman;"> </span><span style="font-family: Times New Roman;">Today, the best coordinates of stations on the ground are obtained by using Global Navigation Satellite Systems (GNSS) such as Global Positioning System (GPS). There are many error sources affecting the GNSS observations that limit the required accuracies. But differential positioning methods, like double difference, are big helps to us to achieve an accuracy of millimeter. Differential operation of GNSS is based on placing a reference station with a GNSS receiver at a known location. One of such errors is the coordinate error of reference station and its propagation on unknown stations. In fact the coordinates of a reference station should be known in a reference system coordinate, such as WGS84 used in GPS, which we usually assume is exactly known. In practice, the position of the reference station in the reference system coordinate may not be exactly known due to different reasons. Therefore, in this study, the effect of the reference station position errors on various ranges from ~4 km to ~90 km, in static mode and using double difference carrier phase, is investigated. The results show this effect could be of the order of a few ppm depending on error magnitude of reference position and the range of baseline. </span>
<span style="font-family: Times New Roman;"> </span>http://www.gsjournal.ir/article_55246_c3470e3d2ed0b82043cf38f0a4e86a02.pdf