What is a virtual reference station?

What is a VRS?

A virtual reference station (VRS) provides centimeter-level positioning accuracy for GPS receivers, without the need for your own physical base station. The VRS draws data from a massive network of reference stations to calculate a localized correction signal rather than a single base station operated by the user. In other words, VRS technology allows users to collect highly precise GPS data points without having to purchase, manage, or set up their own base station.

How does a virtual reference station work?

An RTK network is served by a spread of physical base stations across the coverage area. These base stations are linked to a central computation server. The server aggregates the raw data from the entire network of base stations and uses that data to correct for atmospheric conditions at each point throughout the network, ensuring accurate data.

To create a VRS, the network uses data from multiple fixed base stations to calculate corrections with a near-zero baseline, directly on top of where the rover is at any time. The result is centimeter-accurate data, exactly where the receiver is located, and real-time corrections.

For a more technical explanation, read this article > 

VRS vs. Physical Base Stations

Both virtual reference stations (VRS) and physical base stations offer advantages, depending on the application.

For small surveying projects, a single base station and a receiver can certainly get the job done with minimal setup. As long as the receiver stays within range of the base station, you can count on accurate positional data.

However, if the area being surveyed is too large and the receiver has to go more than 20 or 30 kilometers away from the base station, accuracy starts to slip. You need to add more base stations to ensure correct coordinates, which requires more financial investment and more time spent on location research and setup.

At this stage, it often makes more sense to subscribe to an established RTK network with a robust spread of base stations and the capacity to generate a VRS. This gives you centimeter-level accuracy without the need to purchase and maintain your own base stations. Plus, depending on which network you choose, you can tap into a much larger coverage area.

Plus, a VRS can offer better positional data when contending with challenges such as bad weather, tree cover, and other obstructions, and a lack of dedicated base stations within range.