Balloon Borne GPSsondes that Enable Simultaneous Multi-Point Atmospheric Sensing with a Single Ground Station

Balloon-borne radiosondes provide measurements of in-situ atmospheric data such as wind velocity, temperature, and pressure, amongst many others. The Space and Atmospheric Instrumentation Laboratory at Embry-Riddle Aeronautical University has developed low cost (\u3c $150, all inclusive) GPS-enabled radiosondes that are capable of having multiple balloons simultaneously in the air communicating to a single omni-directional ground station antenna. Each GPS-sonde is equipped with a GPS Module for zonal and meridional winds, thermistor for in-situ temperature, and a pressure sensor. Slant range of greater than 120km is achieved through low-cost LoRa radio modules. Interference-free transmission timing between multiple payloads is done by time division multiplexing. The current design allows for up to six payloads to be simultaneously airborne and transmit live atmospheric data through one ground station. A higher number of simultaneous transmissions are also possible, albeit with a minor hit to spatial resolution. We present the system design, complete with hardware and software details, as well data from our current test flights and plans for future development