Target intensity correction method based on incidence angle and distance for a pulsed Lidar system.

Area of Science:

• Geospatial Science
• Optical Engineering
• Remote Sensing Technology

Background:

• Pulsed light detecting and ranging (Lidar) systems provide distance and intensity data for target characterization.
• Intensity data is crucial for target reflectivity but is affected by incident angle and distance, necessitating calibration.
• Existing methods lack comprehensive correction for these influential factors in Lidar intensity measurements.

Purpose of the Study:

• To develop and validate a target intensity correction method for pulsed Lidar data.
• To address the limitations of incident angle and distance influencing intensity measurements.
• To improve the accuracy of target identification using corrected Lidar intensity data.

Main Methods:

• Derived a pulse echo signal equation incorporating an improved tail model for target detection.
• Established a target echo intensity correction model to normalize intensities to the normal direction.
• Validated the approach through simulations and practical experiments on a pulsed Lidar system.

Main Results:

• Incident angle correction achieved mean absolute errors (MAEs) within 0.04 V, reducing cystosepiment error by 96%.
• Error standard deviations (ESDs) for all corrections remained at or below 0.03 V, demonstrating stability.
• Distance correction under normal incidence yielded MAE and ESD within 0.05 V for various targets.

Conclusions:

• The proposed method effectively corrects pulsed Lidar intensity data for incident angle and distance variations.
• A reflectivity lookup table combined with corrected intensity enables accurate target identification.
• This calibration significantly enhances the reliability and applicability of pulsed Lidar for 3D imaging and analysis.