Implementation of Multimodal Tracking Capabilities for High-Altitude Ballooning

Successful ballooning tracking is a challenging task for many ballooning teams. Several methods of ballooning tracking are known to the ballooning community. In this paper, we present a concept of dual-modal tracking payload integrating an RF radio operating at ~900 MHz and a cellphone-based tracking system operating at ~2 GHz. In particular, we describe how we combined the RF-based and cellphone-based methods to function properly as an integrated module. As part of the implementation details, we also present a processing mechanism implemented on a microcontroller to detect when the payload has landed and turn on the cellphone after landing.