Development and Calibration of Pressure-Temperature-Humidity (PTH) Probes for Distributed Atmospheric Monitoring...

Area of Science:

• Atmospheric Science
• Meteorology
• Unmanned Aircraft Systems (UAS) Technology

Background:

• Small unmanned aircraft systems (UAS) offer potential for distributed atmospheric monitoring.
• Payload limitations on UAS restrict the deployment of sophisticated meteorological sensors.
• Accurate measurement of barometric pressure, temperature, and relative humidity is crucial for atmospheric studies.

Purpose of the Study:

• To develop a miniature, lightweight, and low-power pressure-temperature-humidity (PTH) probe suitable for integration into UAS.
• To calibrate and validate the performance of the developed PTH probes for meteorological measurements.

Main Methods:

• Fabrication of eight miniature PTH probes with mass < 4 g and power consumption < 1 mA.
• Automated calibration and validation using an environmental chamber across various temperature and humidity setpoints.
• Application of linear regression for temperature and relative humidity calibration, and a 1-point offset for barometric pressure calibration.

Main Results:

• Calibrated PTH probes exhibited minimal significant differences in measurements.
• Root Mean Square Error (RMSE) after calibration was < 31 Pa for pressure, < 0.13 °C for temperature, and < 0.8% RH for relative humidity.
• Data transmission at 1 Hz via TTL UART in ASCII format.

Conclusions:

• The developed miniature PTH probes are suitable for UAS integration, overcoming payload constraints.
• Calibrated probes provide accurate and reliable measurements for lower atmospheric boundary layer monitoring.
• These probes will enhance the capability for quantifying ambient condition variations during coordinated multi-UAS flights.