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GNSS observation procedures

Satellite measurement technology works with an accuracy range of within a metre. To achieve accuracy in the centimetre range, differential methods are applied.

Global Navigation Satellite Systems (GNSS)

GNSS observation procedures
With GNSS, it is possible to determine three-dimensional positions worldwide.

With GNSS, it is possible to determine three-dimensional positions worldwide with an accuracy range of 5 to 10 metres using simultaneous observations with 4 GNSS satellites. All that is required is a GNSS receiver, which is available on the market in various versions and with varying accuracy ranges, or is integrated into all mobile phones.

Differential GNSS (DGNSS)

DGNSS observation procedures
The accuracy of GNSS may be increased considerably through the use of a reference station.

The accuracy of GNSS may be increased considerably through the use of a reference station (a GNSS receiver at a location with known coordinates). In the post-processing method, the observations of the rover (a mobile GNSS receiver) are then adjusted so that, depending on the type of receiver, accuracies to within a few decimetres or centimetres can be attained. This differential method may also be carried out in real time. It requires a communication link (radio, mobile phone, etc.) between the reference station and the rover. Depending on the type of GNSS observation (code or carrier phase), the method is referred to as differential GNSS (DGNSS) with accuracy in the metre range, or real-time kinematics (RTK) with accuracy in the centimetre range.

With its swipos product, swisstopo offers DGNSS and RTK positioning services for all of Switzerland, thus rendering the use of personal reference stations obsolete.


Federal Office of Topography swisstopo Seftigenstrasse 264
P.O. Box
3084 Wabern
Tel.
+41 58 469 01 11

E-mail


Relevant authority

Geodesy and Federal Directorate of Cadastral Surveying
E-mail

Federal Office of Topography swisstopo

Seftigenstrasse 264
P.O. Box
3084 Wabern

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