Complexes of functional additions by the size of the territory of action can be classified into local (150 km), regional (1000 km), wide-band (up to 5000 km).
An example of a wide-band system of functional additions is the system of differential correction and monitoring of radio navigation fields (SDCM). The Russian SDCM is a functional addition to the GLONASS and GPS satellite navigation systems, which improves their characteristics for solving tasks requiring high accuracy and reliability.
The SDCM includes a measurement collection complex, including measurement collection stations on the territory of the Russian Federation and abroad, a SDCM center and a complex for delivering information to consumers.
The primary measurement information is sent to the SDCM center, where it is processed in order to clarify ephemeris-time information, determine the integrity parameters of the navigation-time field and form a message for the consumer.
SDCM messages will be delivered to consumers via satellite and terrestrial data transmission channels. The basis of the orbital grouping (OG) SDKM will be the spacecraft of the multifunctional space relay system «Luch» in geostationary orbit.
The SDCM orbital grouping will ensure guaranteed delivery of corrective information to consumers almost throughout the Earth, with the exception of the polar regions and the North American continent.
Simultaneously with the creation of space channels for the delivery of SDCM information, a website providing operational and a posteriori data for monitoring the state of GLONASS and GPS navigation and time fields was put into trial operation. The SDCM information transmission system is being tested over ground communication channels. This will allow you to work out, check and confirm the characteristics of the information generated by the SDCM, without waiting for the launch of the Luch spacecraft.
The commissioning of the SDCM significantly increases the accuracy of navigation definitions. So, if the accuracy of determining the coordinates by the consumer in units of meters is provided in offline mode, then when using information about the SDCM, the accuracy reaches a centimeter level.
In addition, the SDKM will allow solving the tasks of monitoring road transport, drivers’ compliance with traffic rules, boarding and disembarking passengers of a public transport port in designated places. With the help of SDCM, the tasks of monitoring the location of railway trains on adjacent tracks, optimizing the management of shunting locomotives in the areas of marshalling yards and railway junctions will also be solved at a new qualitative level.