Calibration procedure for Slocum glider deployed optical instruments.

Area of Science:

• Oceanography
• Autonomous Underwater Vehicles (AUVs)
• Sensor Technology

Background:

• AUVs are increasingly used for scientific experiments and monitoring.
• AUVs are equipped with various sensors, including optical fluorescence sensors, for real-time data collection.
• Calibration of these sensors is challenging, particularly for in-situ measurements and laboratory analysis of mounted instruments.

Purpose of the Study:

• To address the challenges in calibrating optical sensors on AUVs.
• To develop a method for precise laboratory calibration of AUV-mounted optical instruments.
• To investigate the impact of biofouling on sensor calibration.

Main Methods:

• Development of a specialized calibration chamber for Slocum glider instruments.
• Performing pre- and post-deployment calibrations for optical fluorescence instruments.
• Analysis of changes in calibration scaling factors due to biofouling.

Main Results:

• The developed calibration chamber allows precise calibration of optical instruments.
• Biofouling was found to cause significant changes in the calibration scaling factors of fluorescent sensors.
• Pre- and post-deployment calibrations revealed sensor performance variations.

Conclusions:

• Consistent and repetitive calibrations are necessary for accurate AUV data.
• The developed calibration method is applicable to AUVs and other platforms.
• Addressing biofouling effects through regular calibration is essential for long-term AUV deployments.