ARK Electronics G5 RTK GPS

The ARK G5 RTK GPS from US maker ARK Electronics is a compact RTK-capable GNSS module for medium-class multicopters. Its receiver is the Septentrio mosaic-G5 P3. The unit is built in the USA and, according to the manufacturer, is NDAA compliant, which matters mainly for buyers bound by US federal procurement rules.

The receiver works in four frequency bands and handles GPS, GLONASS, Galileo, BeiDou, QZSS and NavIC, plus the Galileo High Accuracy Service (HAS). Several bands let the receiver remove the ionospheric delay, so the RTK solution arrives sooner and holds up better in poor reception. The manufacturer describes the RTK accuracy as centimetre class. Position is output at 20 Hz, meaning 20 times per second, enough for fast flight and tight control loops. A magnetometer, the ST IIS2MDC, sits in the housing; the module connects through two CAN ports, UART or USB-C. It weighs 13 g without antenna and 43.5 g with antenna.

The rules apply to the aircraft, not the module: the EU classes C1 to C3 (take-off mass below 900 g, 4 kg and 25 kg) require geo-awareness and direct remote identification, and both draw on the GNSS position. RTK makes that position more accurate but replaces none of these duties. Correction data can come from your own base station, over a radio link, or from an NTRIP service over the mobile network, for example from national survey authorities (SAPOS in Germany, ASG-EUPOS in Poland).

Mounting is decided by the antenna: a clear view of the sky, distance from the video transmitter, telemetry and power leads, and a conductive ground plane beneath the antenna. The compass is calibrated after installation and checked after any large change of location. Before take-off the autopilot shows whether the RTK status is fix or only float; the centimetre class applies only at fix. Antenna connectors wear under vibration; receiver and autopilot firmware need updates.