Good To Know



RTK, GPS and GNSS… the precise guidance brings with it a lot of technical terms. Reason enough to take a closer look at the most important terms and to learn more about the themes and background relating to our correction data service FarmRTK.

General Terms

With FarmRTK AXIO-NET GmbH provides correction data services in Germany, but also in Great Britain, Denmark and the Netherlands. Correction data are calculated by means of reference stations that are available nationwide. These correction data are transmitted via mobile telephone to the GPS system of the machine, thus enabling a centimetre-exact position and guidance of the machine. Similar services have been provided by AXIO-NET for several years in the areas of land survey and construction.

FarmRTK provides via mobile telephone correction data for satellite-based guidance systems which enable the agricultural machines to be guided easily and simply with an accuracy of up to 2 centimetres.

Precision Farming
Precision Farming means that, when tilling the field, the farmer adopts to the differences of the soil and to the different yields resulting from this. Once mapped the field, he is able to register and document to a square metre accuracy the places where are the strengths and weaknesses of the field. Afterwards, he will sow the seed as well as the fertilizers and pesticides exactly according to the needs instead of distributing them evenly.

The farmer can e.g. drive the tracks, record the exact positions and put every single track next to the previous one with centimetre accuracy in order to avoid the omission of a line or the duplicate passes on o
verlapping lines. This process works even on fields with serpentine lines and is exactly repeatable year by year thanks to FarmRTK.

Satellite Systems

The Global Positioning System is the satellite positioning system of the USA. 32 satellites are circling the earth on 6 orbits and make possible global positioning around the clock. FarmRTK provides correction data using this established system.

Global Navigation Satellite System is the Russian positioning system and an equivalent to the US-American GPS. The fundamental principles are the same; however, a major difference is that every satellite is sending out signals on its own frequency. When using t FarmRTK services you are able to receive GLONASS data along with GPS.

Galileo is the name of the European satellite navigation system and is currently in the construction. It is based on 30 satellites (27 + 3 substitutes) that orbit the earth at a height of 24,000 km. They are controlled by a network of ground stations. In contrast to the US-American GPS and the Russian GLONASS, Galileo is constructed for civilian purposes only and is not submitted to a national military control.

Global Navigation Satellite System – the general term for all current satellite-based positioning systems in use. GNSS usually includes GPS and GLONASS and in the future GALILEO, too.

Data Transmission

Is the abbreviation for General Packet Radio System and is a service based on GSM, which enables the supply of correction data in the form of data packets via the internet.

Is the abbreviation for Global System for Mobile Communication and comprises the whole infrastructure that is necessary for a communication made by cell phones. GSM is mainly used for telephony.

DGPS (differential GPS) is the general term for GPS measuring methods with reduced accuracies, i.e. accuracies in the submetre range. In this procedure two or more GPS receivers are used. The accuracy of DGPS systems is 1-5 metres.

Reference Station
Reference stations whose positions are determined for millimetre-level receive permanently signals transmitted from the navigation satellites. All stations are connected via a data line with a computing centre from where a computer permanently and at one-second intervals, receives and updates the data from all reference stations. Finally, the data are converted into correction data.

Atmospheric Errors
They are errors that distort the satellite signals due to atmospheric turbulences before they reach the receiver. When calculating the correction data of FarmRTK, the atmospheric errors are taken into account and the accuracy of the signals is enhanced.