Inconsistent GNSS Data Accuracy with External Sensors

[bovovnausard]

Hello

I have been facing inconsistent data accuracy when using an external GNSS sensor with Harry's LapTimer. During high-speed laps; the location precision occasionally drops significantly; even under clear sky conditions. This leads to inaccuracies in lap timing and GPS traces; affecting overall reliability.

I am using a Qstarz BL-1000GT GNSS sensor; with all settings configured according to the user manual. I have checked viewforum.php?f=19msbi guide for reference .

Could this issue be related to sensor compatibility, firmware configuration, or possible interference from nearby devices? Additionally; would adjusting the GNSS update rate (e.g., from 10 Hz to 5 Hz) or tweaking phone settings improve stability?


I would appreciate any advice to optimize the performance of my setup.

Thank you !

[Harry]

The most frequent reason GPS accuracy drops in certain areas is about the place the sensor is installed. Ideally it has a free view to the sky. With an external GPS, you may try taping it to your car's roof. Most Qstarz GPS suffer from CPU overload when running them at high update rates. In particular, DGPS (differential GPS to improve accuracy) may be turned off at high rates. Please check for your model.