GPR Processing
PolarWave can process Ground-Penetrating Radar (GPR) scan files. Upload your file and the platform handles everything automatically — you go straight from upload to an interactive visualization.
Uploading a GPR file
Go to GPR under Instruments in the left navigation, then click Select File or drag-and-drop your GPR file. The platform recognizes GPR files automatically.
GPR files can be large. Upload time depends on your connection speed. Processing typically completes within 10–60 seconds — refresh the table if the scan still shows as "Processing".
Viewing GPR data
GPR scans support the same three views as magnetometer scans:
1D — Depth profile
Shows a single scan line. The horizontal axis is the along-track distance and the vertical axis is signal amplitude vs. depth. Strong reflectors appear as peaks.
2D — Radargram
The classic GPR view:
- Horizontal axis — along-track distance
- Vertical axis — depth (two-way travel time)
- Color — signal amplitude
Buried objects appear as hyperbolic reflections.
3D — Volume slice
The radargram data rendered as a 3D surface. Rotate and zoom to inspect depth layers.
Interpreting GPR data
Hyperbolic reflections
The most recognizable GPR signature is a hyperbola. As the antenna passes over a buried object, the radar pulse travels an increasing path length, producing a characteristic arc in the radargram. The apex of the hyperbola marks the horizontal position of the object. Depth is estimated from the apex timing and the propagation velocity of the ground.
Estimating depth
Depth (m) = (two-way travel time in ns × propagation velocity) ÷ 2
Typical propagation velocities:
| Material | Velocity |
|---|---|
| Dry sand | ~0.15 m/ns |
| Moist soil | ~0.08 m/ns |
| Clay | ~0.06 m/ns |
| Concrete | ~0.12 m/ns |
Applying filters to GPR data
| Filter | Recommended use |
|---|---|
| Decimation | Speed up display of large files |
| Amplification | Boost deep reflectors weakened by signal attenuation |
| Smoothing | Reduce background clutter |
| Detrend | Remove horizontal banding from the direct wave and ground wave |
| Baseline Removal | Zero-center each depth slice to improve contrast |
Common artifacts
| Artifact | Cause | How to identify |
|---|---|---|
| Direct wave | Air/ground coupling at the surface | Strong horizontal band at the very top of the radargram |
| Ringing | Multiple reflections between antenna and ground | Repeating horizontal bands at regular intervals |
| Migration smearing | Unprocessed hyperbolas | Broad arc shapes instead of tight point reflectors |
| Clutter | Surface objects or reinforcement mesh | Many overlapping arcs |
Exporting data
From the scan toolbar you can download your processed data for use in other software.