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

Incredibly feature-rich app in an incredibly small package. VERY accurate GPS positioning, altitude and compass! I just wish my Google Pixel 9 Pro XL could use its engine for storing picture GPS location instead of the camera's built-in engine, which is extremely inaccurate (it wanders all over the place and can be off by hundreds of feet even outside)

Good app! But I have a question, why is there a difference between weighted least squares solution and GPS provider? Whereas GPS system uses WLS. Maybe there are corrections (using sensors and Wi-Fi for example) but in this case, what is the difference between fused location and GPS provider? Thanks

App broken, was good before the option to download the data jumped from sending emails to wanting to uselessly text the large datafiles. There is no way to reset this, even uninstalling and reinstalling keeps this setting which means it is impossible to use the program for any serious testing. Even before this very serious bug getting the data out was flakey as it was easy to press wrong part of screen, loose the option to download and have to repeat the experiment. UPDATE, reset apps and fixed.

What’s new

• Log game rotation vector sensor - Uses accelerometer and gyroscope for orientation (no magnetometer, so reference is not north).
• Settings screen on watch - Turn on and off various settings similar to the phone app.
• Map screen on watch - Shows real-time chipset GNSS position on map.