Influence investigation on ranging performance for range-gated Geiger-mode avalanche photodiode ladar

Area of Science:

• Optics and Photonics
• Laser Technology
• Signal Processing

Background:

• Geiger-mode avalanche photodiode (Gm-APD) ladar performance is typically assessed by range accuracy and precision.
• Existing methods struggle to comprehensively evaluate parameter influences across the entire detection gate due to stochastic target echoes.
• Theoretical calculations may not fully capture real-world ladar ranging performance.

Purpose of the Study:

• To develop a novel theoretical framework for objectively evaluating Gm-APD ladar ranging performance.
• To analyze the impact of key operational parameters on ladar accuracy and precision.
• To provide practical recommendations for optimizing Gm-APD ladar systems.

Main Methods:

• Application of the central limit theorem, assuming Gaussian distribution for target positions within the gate.
• Integration of the Gm-APD triggering probability model with the proposed mean ranging accuracy and precision theory.
• Combination of the developed theory with the standard ladar ranging equation.

Main Results:

• Identified that high laser transmitting energy, narrow gate width, short target range, and low noise intensity lead to lower mean ranging accuracy and precision.
• Determined that narrow pulse width decreases mean ranging accuracy but increases mean ranging precision, while wide pulse width has opposite effects.
• Established that a pulse width between 10–30 ns is optimal for balanced ranging performance.

Conclusions:

• The proposed mean ranging accuracy and precision theory offers an objective method for evaluating Gm-APD ladar performance.
• Parameter optimization, including reducing gate width, increasing laser energy, and using narrowband filters, is crucial for enhancing ladar ranging.
• The findings provide significant guidance for experimental parameter selection in Gm-APD ladar development.