Aerial Tracking and GNSS-Reference Localization with a Robotic Total Station

Precise navigation for small unmanned aerial systems is of high interest for disaster scenarios and many other tasks. Advanced navigation technologies for future low-altitude applications in completely or partly unknown environments are carried out by DLR's Unmanned Aircraft Department in cooperation with the Institute of Flight Guidance from the Technical University Braunschweig. This paper describes the usage of a robotic total station as a reference localization system in order to benchmark current and developing satellite, inertial, and optical navigation techniques. Such devices perform laser-based distance measurements to the aircraft and track the moving vehicle. Since total stations are not mainly designed for aerial applications, the paper includes the description of some required extensions like faster automatic targeting and time synchronization. The paper concludes with the analysis of helicopter flight tests, where satellite-based localization results from different receivers are compared with the total station reference measurements