GnssLogger App

Developed with Google

About this app

GnssLogger by Google enables in-depth analysis and logging of all types of location and sensor data such as GPS (Global Positioning System), network location and other sensor data. GnssLogger is available for phones and watches. It comes with the following features for phones:

HOME TAB:
● Control various data logging such as raw GNSS measurements, GnssStatus, NMEA, navigation messages, sensor data and RINEX logs.

LOG TAB:
● View all location and raw measurement data.
● Control offline logging using 'Start Log', 'Stop & Send' and 'Timed Log'.
● Enable specific items to be logged using corresponding switches in Home Tab.
● Delete existing log files from disk.

MAP TAB:
● Visualize on GoogleMap, the location provided by GPS chipset, Network Location Provider (NLP), Fused Location Provider (FLP), and computed Weighted Least Square (WLS) position.
● Toggle between different map views and location types.

PLOTS TAB:
● Visualize CN0 (Signal Strength), PR (pseudorange) Residual and PRR (pseudorange rate) Residual vs time.

STATUS TAB:
● View detailed information of all visible GNSS (Global Navigation Satellite System) satellites such as GPS, Beidou (BDS), QZSS, GAL (Galileo), GLO (GLONASS) and IRNSS.

SKYPLOT TAB:
● Visualize the data of all visible GNSS satellites using a skyplot.
● View the average CN0 of all the satellites in view and the ones used in fix.

AGNSS TAB:
● Experiment with Assisted-GNSS functionalities.

WLS Analysis TAB:
● View the Weighted Least Square position, velocity and their uncertainties computed based on raw GNSS measurements.
● Compare the WLS results to the GNSS chipset reported values.

It comes with the following features for watches running Wear OS 3.0 and higher:

● View real-time GNSS chipset status information.
● Log various GNSS and sensor data to CSV and RINEX files.

Ratings and reviews

Edit: version 3.0.6.1 fixes the problems I had, everything works great now. Thanks for the communication, devs! Original review below: Signal strength plot doesn't seem to work at all. Yes, I've tried it outside. Status and Skyplot tabs show satellites, Map shows my location. The problem is with the Plots tab not displaying any graphs, only an empty white area, with the text "No Measurement has been received yet. Please turn on Measurement and Location in Home tab." Yes, they are both enabled.

I am getting much better performance after the recent update. Now that it works, I am very happy with this app. It is great for GNSS analysis. My two only gripes. I can not figure out how to log sensor data. When I check Log Sensor on the main screen, nothing additional shows up in the log. And my second gripe is that the log clears everytime I go to another screen, even with the app running in the background, so I can't log data while using Google maps to navigate.

This app is amazing, thanks a lot for developing it. But, there are still gaps into the raw measurements, it is something like it freezing after one hour, or two. After a freezing of approximately 3 hour, it starts again to measure which is very uncomfortable. (all battery optimization options are disable for this app). Thank you so much!

What's new

• Now available for WearOS - Download GnssLogger for Android smartwatches from Google Play!
• Measurements tab - See a real-time snapshot of raw measurement details, including code type, measurement state, and ADR state.
• Spoof/Jam tab - See a real-time plot of automatic gain control (AGC) and related analysis.
• RINEX log enhancements - RINEX v4.01 support, ADR/Carrier Phase is now aligned.