Range walk error compensation for SLR using fiber-coupled SNSPDs based on differential attenuation method

Area of Science:

• Geodesy
• Photonics
• Quantum Optics

Background:

• Satellite laser ranging (SLR) applications utilize superconducting nanowire single photon detectors (SNSPDs).
• SNSPD response characteristics can introduce range walk errors, impacting ranging accuracy.
• Minimizing range walk errors is crucial for enhancing SLR precision.

Purpose of the Study:

• To propose and validate a novel method for compensating range walk errors in SLR.
• To theoretically analyze factors contributing to range walk errors.
• To improve the ranging accuracy of SLR systems.

Main Methods:

• Developed a detection probability model considering echo pulse energy, time jitter, and pulse width.
• Proposed the differential attenuation walk compensation (DAWC) method.
• Implemented experimental validation using a corner reflector and fiber optic attenuator before SNSPDs.

Main Results:

• Theoretical analysis confirmed that attenuating echo signals to the single-photon level and using differential delay can compensate range walk errors.
• Experimental results showed an enhancement in ranging accuracy by 0.14 ns RMS.
• Demonstrated an effective compensation of at least 40% for range walk errors.

Conclusions:

• The DAWC method effectively compensates for range walk errors in SLR.
• This approach offers a promising solution for improving SLR precision.
• The findings contribute to advancements in high-accuracy satellite laser ranging.