ARK Electronics RTK GPS

The ARK RTK GPS from US maker ARK Electronics is a DroneCAN RTK GNSS module for medium-class multicopters. It is based on the u-blox ZED-F9P and adds an IMU, a barometer and a safety switch to the receiver. The module supports heading determination by moving baseline.

The standard model receives GPS, GLONASS, Galileo and BeiDou on L1 and L2; a variant with the ZED-F9P-15B uses L1 and L5 instead. The 1.0 cm figure comes from the chip maker, not the module maker: for the ZED-F9P u-blox states 0.01 m + 1 ppm as CEP, the radius containing half of the measurements. 1 ppm is 1 mm per kilometre of distance from the base. In normal operation the module outputs 10 Hz, in moving-baseline operation 5 Hz. The compass is a Bosch BMM150; connection is through two CAN ports or the second UART of the F9P. The weight is 16 g.

Moving baseline means two receivers work out the aircraft's orientation from the separation of their antennas, without relying on the magnetic compass. That helps on frames with a lot of current and metal around the compass. Only the L1/L2 model offers this function. Legally the aircraft is what counts: the EU classes C1 to C3 require geo-awareness and remote ID, both rely on the GNSS position, and RTK improves the position but removes no duty. Corrections come from a base station, a radio link or NTRIP.

For selection the variant decides: L1/L2 for heading by moving baseline, L1/L5 when the newer signals are wanted. Anyone who needs both output rates plans for 10 Hz in normal operation and 5 Hz with heading. The safety switch belongs to arming and should be placed within reach at installation. Upkeep includes compass calibration after installation, CAN node firmware matched to the autopilot version, and a look at the antenna connectors after hard landings.