In this study, a location and altitude-based warning and collision awareness and advisory prototype was designed and two functional prototypes were developed to reduce the risk of collisions that may occur when hot air balloons cannot see each other in the air. Each prototype used a Raspberry Pi-4, 7-inch touch screen, LoRa communication module, BMP180 pressure sensor, MPU6050 accelerometer, and a GY-GPSV3 NEO-8 M Global Navigation Satellite Systems (GNSS) module. The balloons’ location, altitude, and speed information were mutually broadcast via the LoRa module; the data of the intruder balloon located within a horizontal 500 m radius was visualized with an interface similar to the Traffic Alert and Collision Avoidance System (TCAS) in aircraft. The system offers a resolution advisory (RA) at distances of 100 m and closer. It produces a traffic advisory (TA) at distances between 100 and 200 m. In the tests carried out on the ground and in the hot air balloon, the system’s location detection accuracy, the functionality of the warning algorithms, the detection of flight phases, and the information levels in the designed interface were analyzed. The findings have shown that this system, which leverages low-cost GNSS technology for cooperative awareness, is open to development and represents a novel application of positioning technology to fill a gap in preventing accidents that may occur after balloons come into contact with each other, making a contribution to the hot air balloon industry.