NAVCAST

NAVCAST is a high-accuracy GNSS correction service from Spaceopal GmbH, the Galileo service operator set up as a joint venture of DLR GfR and Telespazio. Standalone Galileo and GPS positioning is limited by errors in the broadcast satellite orbits and clocks. Precise Point Positioning (PPP) removes these errors without local reference stations, provided precise satellite orbit and clock corrections are available.

NAVCAST takes observations from more than 100 Galileo and GPS receivers worldwide and computes real-time orbit and clock corrections with the RETICLE algorithm developed by the German Aerospace Center (DLR). It adds code and phase biases, including GPS L5 code biases. Corrections cover Galileo E1, E5a and E5b and GPS L1 and L2 and are referenced to ITRF2014. They are encoded in RTCM 3 and streamed worldwide to registered users over NTRIP 2.0, with clock updates every five seconds and orbit updates every 30 seconds. Users apply them to their own raw Galileo and GPS measurements through an NTRIP client and a PPP engine. Spaceopal gives typical accuracy at the 20-centimetre level, converging to centimetre level, for navigation, surveying, machine guidance, sensor geo-referencing and scientific geodesy. Its published benchmarks against IGS products from CODE and GFZ show orbit errors below 5 cm RMS and clock errors below 0.2 ns RMS.

A companion desktop tool, 3PNg, is available to registered users on request and post-processes RINEX observations to give static or kinematic PPP. In 2020 Spaceopal also released 3PGo, an Android app that runs PPP on smartphone raw measurements and exports tracks as KML. Spaceopal describes NAVCAST as a prototype service. It launched in October 2018, and by October 2020 it had users in more than forty countries.