RTCM

RTCM (Radio Technical Commission for Maritime) is a protocol that supports transferring a variety of correction messages from a base station to a rover (or in our case a drone). In an RTK-enabled GNSS system, RTCM data must be regularly generated/transmitted by the base station and received by the rover to attain cm-level accuracy. Data is sent at roughly 1 Hz, or once per second. If an RTCM stream is lost, GNSS accuracy will degrade until standard 3D-Fix is reached (~3 meters). This is well beyond the inter-drone distance used during show design, so a loss of RTCM can result in collisions.

If you've ever seen a drone show look "fuzzy" or chaotic, then it is most likely due to a loss of RTCM.

Data Transfer

In Verge Aero's system, RTCM data is transmitted via LoRa radio. As this is the only data stream that is absolutely necessary during an active drone show, LoRa maximizes the likelihood of successful reception. RTCM data is also optionally sent over the AT86, however it requires that a Verge Aero Console be connected and active. Having multiple radio paths improves the system's robustness.