Performance of Real-Time Kinematic Global Navigation Satellite System Receivers on Unmanned Aircraft Systems for Precision Meteorology

Small unmanned aircraft systems (UAS), also known as drones, represent new platforms for strategically locating meteorological sensors in the lower boundary layer atmosphere. Small UAS under automated or semi-autonomous control typically use single frequency global navigation satellite system (GNSS) receivers under standard or differential fix configurations – exhibiting typical horizontal and vertical accuracies of 5 m and 15 m, respectively. The low vertical accuracy is particularly problematic for meteorological applications where barometric pressure is measured. Real-time kinematic (RTK) GNSS receivers enhance measurement accuracy to less than a few centimeters under static conditions at ground level. However, little information exists on how deployment strategies affects accuracy. This project has two main objectives. The first objective is to experimentally determine the static and dynamic accuracy of low-cost single and multi-frequency real-time kinematic (RTK) global navigation satellite system (GNSS) receivers with an emphasis on elevation measurements. The second is to prototype a custom pressure/temperature/humidity (PTH) probe and test the system against a benchmark Mesonet tower. Both objectives incorporate training opportunities for a PhD student under supervision of a faculty mentor and professional staff. The student will gain experience in embedded systems design and fabrication, sensor calibration and validation, and small UAS operations. Anticipated outcomes of this work include quantification of how accurately elevation of small UAS can be measured when profiling the lower boundary layer atmosphere, a custom PTH probe that is designed specifically for small UAS operations, and a PhD student trained in an experiential learning environment.