Effect of incidence angle on laser scanner intensity and surface data
Antero Kukko1, Sanna Kaasalainen, Paula Litkey
1Department of Remote Sensing and Photogrammetry, Finnish Geodetic Institute, P.O. Box 15, FIN-02431 Masala, Finland. antero.kukko@fgi.fi
Applied Optics
|March 4, 2008
Summary
Laser intensity measurements show a significant angle of incidence effect, especially for bright targets. This study provides crucial data for laser scanning and airborne laser scanning (ALS) calibration.
Area of Science:
- Geospatial Science
- Remote Sensing Technology
- Laser Physics
Background:
- Laser intensity is crucial for accurate remote sensing data interpretation.
- Understanding the influence of surface properties on laser returns is essential for calibration.
Purpose of the Study:
- To experimentally investigate the relationship between laser intensity and the angle of incidence.
- To compare terrestrial and airborne laser scanning (ALS) data.
- To identify factors influencing laser intensity variations.
Main Methods:
- Laboratory measurements using a Nd:YAG laser and terrestrial laser scanner.
- Comparison of brightness scale data with airborne laser scanning (ALS) data.
- Analysis of various target surfaces, including gravel samples.
Main Results:
- A clear dependence of laser intensity on the angle of incidence was observed for all targets.
- The effect becomes significant for angles greater than 20 degrees and is more pronounced for brighter surfaces.
- Surface properties like roughness also influence laser returns.
- Gravel samples exhibited a minor incidence angle effect up to 40 degrees.
Conclusions:
- The angle of incidence is a critical factor affecting laser intensity measurements.
- The findings offer valuable reference data for full-waveform processing and ALS intensity calibration.
- Surface characteristics can mitigate or exacerbate the incidence angle effect.
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