About GNSS Calculator

GNSS Calculator is a free, open-source tool for GNSS engineers and anyone working with satellite navigation data. Convert timestamps, transform coordinates, inspect NMEA logs, browse RINEX observations, connect to NTRIP casters, and explore GNSS signal spectra — all in the browser, with nothing to install.

Why I built this

During my years working with GNSS — first at GMV, then at Airbus Defence and Space, and later as a Product Engineer at Leica Geosystems — I found myself constantly jumping between scattered scripts and outdated web tools to do everyday calculations. I wanted a single, fast, reliable place to do them all. So I built one.

This is a spare-time, one-person project. I design, build and maintain everything myself. If you find it useful, that means a lot.

About me

I'm Miguel González, an aerospace engineer based in Madrid. I hold a BSc in Aerospace Engineering (Air Navigation Systems) and an MSc in Signal Theory and Communications. After several years in the GNSS and space industry I moved into data science and machine learning, and I currently work as a Senior LLM Engineer at A5 Labs.

You can find out more about me at miguel.es, or reach out on LinkedIn.

Open source

The full source code is available on GitHub. Contributions, bug reports and feature requests are welcome.

Tools

• GPS Time Converter — convert between GPS, Galileo, BeiDou, UNIX, UTC, Julian Date and more
• Positioning Calculator — ECEF, geodetic, UTM, AER, ENU, distances and bearings
• RINEX Viewer — multipath, cycle slips, completeness, C/N0, sky plots and DOP
• NTRIP Client — browse casters, view mountpoints on a map, monitor RTCM streams
• Broadcast Ephemeris — live satellite health and orbital parameters from the IGS
• NMEA Log Viewer — parse GGA/RMC sentences, view tracks on a map
• Signal Spectrum — interactive PSD chart of all GNSS L-band signals
• ANTEX Antenna Viewer — phase center offsets and variations for receiver and satellite antennas