GeigerGPX is an Android application designed to simultaneously record GPS tracks and dose-rate data from a Geiger counter.
Currently, RADEX RD1008 (РАДЭКС РД1008) and RADEX RD1224Si are supported.
No hardware modifications are required; the app records signals directly via the microphone (an external wired microphone is recommended). To use the app, simply enable audio output on your device:
- RD1008: Switch to "search" mode, set the threshold to zero, and turn on the sound.
- RD1224Si: Enable "quantum sound."
- Audio pulse detection: Utilizes three Goertzel filters (tuned to 3276.8 Hz for the RD1008, plus two witness filters) alongside a pulse duration filter for accurate detection.
- GPS & dose recording: Records your geographic position and overlays dose-rate data onto the track timeline.
- GPX export: Saves tracks in GPX format with custom extensions for dose-rate data. (Standard GPX viewers will display the path but not the dose information.)
- Dose-aware mapping: Visualize recorded tracks on a map using color-graded lines or generate heat maps from multiple tracks.
- Real-time dose rate preview: Displays a fast, real-time dose rate estimate based on the last 10 detected pulses.
- Confidence interval calculation: Automatically calculates confidence intervals (CIs) using χ² quantiles at a 95% confidence level.
- Long-term measurement mode: Useful for long-duration sampling in low-background environments.
- Measurement results export: Saves detailed measurement results to a separate GPX file using tags that include descriptions, coordinates, timestamps, dose rates, and CI data.
- Dose rate plots: View dose rate plots for recorded tracks with adjustable averaging windows (fixed-duration or Epanechnikov kernel estimator).
- Track editing: Crop the start or end of a track, split tracks, or flag specific points as "bad" to exclude them from map visualizations.
- Bluetooth audio (experimental): Supports audio capture via Bluetooth headsets, though stability and quality are currently lower than wired or built-in microphone input.
Note: At high dose rates, the dosimeter may not audibly emit every pulse, so phone-side estimates can be biased low.
