UAV-Based Demonstration of Alternative PNT at X-Band

<title>Abstract</title> This paper presents an experimental alternative positioning, navigation, and timing system for ground users, implemented at X-band, and demonstrated using a formation of four small unmanned aerial vehicles. The experimental system is designed to support stand-alone ground user positioning at the few-meter level within 30 s and to study the features and characteristics of X-band for this purpose. The payload that creates the X-band transmissions (8.52 GHz) and the user receiver are both based on commercial-off-the-shelf components and a software-defined radio architecture, enabling the study of various signal designs and receiver acquisition and tracking strategies. Horizontal positioning at a level of 1.5 m (root mean square) is demonstrated for both static and moving receivers. Examples of the tracking performance and multipath effects on individual signals highlight the effectiveness of the signal design and the payload and receiver implementations.