GnssLogger App

GnssLogger App by Google is the professional-grade GNSS data logging tool designed for engineers, researchers, and location technology enthusiasts who need raw satellite positioning insights. Capture, analyze, and visualize every aspect of your device's location data in ways standard maps cannot.

Take command of comprehensive data logging from day one. Control raw GNSS measurements, GnssStatus updates, NMEA sentences, navigation messages, sensor fusion data, and RINEX files—all from an intuitive Home Tab. Start, stop, or schedule logging with precision using timed sessions, and manage your files directly within the app. The Log Tab gives you complete visibility into every measurement your chipset collects, enabling deep dives into positioning accuracy and consistency.

Visualize your location story across multiple perspectives. The Map Tab renders GPS, Network Location Provider, Fused Location Provider, and Weighted Least Square computed positions on Google Maps, letting you compare methods side by side. Switch between map views to understand how different positioning sources align or diverge. For signal analysis, the Plots Tab displays signal strength, pseudorange residuals, and pseudorange rate residuals over time—critical metrics for diagnosing reception quality and multipath interference.

Explore satellite constellations with technical precision. The Status Tab presents detailed information about all visible GNSS satellites, including GPS, Beidou, QZSS, Galileo, GLONASS, and IRNSS systems. The Skyplot Tab visualizes satellite geometry and signal strength distribution, showing both average CN0 across all satellites and those actively used in position fixes. For advanced testing, the Assisted-GNSS Tab lets you experiment with A-GNSS functionality to optimize cold and warm start performance.

Gain mathematical insight into positioning accuracy. The WLS Analysis Tab computes Weighted Least Square position, velocity, and uncertainty estimates directly from raw measurements, then compares results against your chipset's reported values. This direct comparison reveals where your device's algorithms succeed and where they might struggle.

GnssLogger App extends beyond phones to Wear OS 3.0 smartwatches, delivering real-time chipset status monitoring and CSV and RINEX file logging on wrist-worn devices. Whether you're validating location services, conducting field research, or optimizing GNSS performance across your product line, this app provides the transparency and control professional development demands.