ARK Electronics MOSAIC-X5 RTK GPS

The ARK MOSAIC-X5 RTK GPS from US maker ARK Electronics is an RTK-capable GNSS module for heavy multicopters. It carries the Septentrio mosaic-X5 receiver, talks DroneCAN to the flight controller and records data to a microSD slot in the unit itself.

The receiver covers the L1, L2 and L5 bands and handles GPS, GLONASS, Galileo, BeiDou, QZSS, NavIC and SBAS. Three bands allow a clean correction of the ionosphere, even with an unfavourable satellite geometry. The accuracy figure belongs to the chip, not to the module maker: for the mosaic-X5 in RTK mode Septentrio states 0.6 cm + 0.5 ppm horizontally. The 0.5 ppm means 0.5 mm of added error per kilometre of distance from the base; what reaches the aircraft depends on antenna and installation. At 100 Hz the module produces very dense position data. A magnetometer, the ST IIS2MDC, is built in; the unit connects through two CAN ports, the GPS port (UART or I2C) or USB-C. It weighs 21 g.

Heavy multicopters quickly exceed the 25 kg limit of the open category; above it the specific category applies, with an operational authorisation. For photogrammetry with georeferencing, 100 Hz and the onboard log provide the basis for reducing ground control points; check points remain useful for verification. Correction data come from your own base, a radio link or an NTRIP service, in Germany for example via SAPOS, in Poland via ASG-EUPOS.

For selection, what happens to the logs matters: post-processing (PPK) needs base data from the same period, and the card must be properly formatted and have enough space before take-off. On the CAN bus, clean harnesses and correct bus termination are part of upkeep, and for firmware updates the autopilot and the module should be considered together. The compass is calibrated after installation; the antenna needs a clear sky view and a ground plane.