REAL TIME KINEMATIC (RTK)

RTK (Real Time Kinematic) is a service that allows users to receive corrections to measurements and establish position with centimetre accuracy in real time by using a GNSS receiver and a SSPP Permanent stations network. The service is available to any user who has a GNSS receiver capable of receiving RTK corrections via a GSM/GPRS connection of the mobile network operator or other communication channels that provide access to the Internet.

RTK corrections are generated by Leica GNSS Spider software and can be provided in the following ways:

Virtual Reference Station (VRS);

Flachen-Korrektur-Parameter (FKP) - area corrections method;

Master-Auxiliary corrections (MAX) - based on the MAC (Master Auxiliary Concept);

Individual MAX (i-MAX).

RTK corrections are transmitted as standardized messages in various formats: RTCM v2.x, v3.x, Leica, Leica 4G, CMR, CMR+, NMEA etc. Transmission is provided by NTRIP (Networked Transport of RTCM via Internet Protocol).

 

 

Real-time kinematic (RTK) positioning

 

Operating principle of BelarusVRS (step by step):

1. The Permanent Stations network equipment continuously receives signals from various Global Navigation Satellite Systems (GNSS) with an information recording interval of 15 seconds.

2. User switches on the RTK receiver (rover).

3. When the connection is established, the receiver sends the navigation coordinates to the data centre server via GPRS modem.

4. The network RTK software calculates the virtual base and correction for user's receiver in relation to the Virtual Reference Station. In cases where there is no possibility of forming a Virtual Reference Station and at a distance of 5 km to the Permanent Station, the SSPP Data Centre software automatically redirects the user to receive corrections from a physical reference station.

5. The RTK correction is sent to the user's receiver.

6. The user starts working with an accuracy in the centimetre range.

 

         Operating principle of NEAR

Operating principle of NEAR

1. The Permanent Stations network equipment continuously receives signals from various Global Navigation Satellite Systems (GNSS) with an information recording interval of 15 seconds.

2. The user switches on the RTK receiver (rover).

3. When the connection is established, the receiver sends the navigation coordinates to the data centre server via GPRS modem.

4. The network RTK software calculates the distance to an active permanent station, selects the nearest permanent station to operate and the correction for the user's receiver relative to the active reference station.

5. The DMA correction is sent to the user's receiver.

6. The user starts working with an accuracy in the centimetre range.

Description of NTRIP Protocol

Description of RTCM format

 

POST-PROCESSING MODE

 

Measurement method can be chosen by user.

For operation in post-processing mode, interval files of permanent (base) stations observations are generated in RINEX v.2.11 format. This data can be used by the user by selecting the data from the FTP-server of the SSPP after signing an agreement and receiving account data for operation.

The angle of satellites elevation relative to a permanent station is 5 degrees.

Satellite measurement recording interval (reception and recording discreteness) for post-processing mode is 15 seconds.