Small unmanned aircraft system (sUAS), as defined by the FAA, refers to a small unmanned aircraft weighing less than 55 pounds on takeoff, and its associated elements that are required for the safe and efficient operation of the small unmanned aircraft in the national airspace system. The unmanned aircraft system (UAS) traffic management (UTM) system is envisioned by NASA to enable civilian low-altitude airspace and UAS operations by providing services such as airspace design, corridors, dynamic geofencing, severe weather and wind avoidance, congestion management, terrain avoidance, route planning and rerouting, separation management, sequencing and spacing, and contingency management. Trajectory modeling and prediction methods are foundational capabilities in support of UTM to achieve its goals. This paper presents a framework for the development and validation of trajectory modeling and prediction methods for diverse types of sUASs under nominal environment and under a variety of realistic potential hazards, including adverse environmental conditions, and vehicle and system failures. Results from initial analysis of major components of the framework are also presented. Detailed results from the development and validation will be reported in subsequent papers as the research progresses.

Most of airborne cameras usually have two actuation axes(roll and pitch) to stabilize and point LOS(Line Of Sight) to a desirable direction. This two-axis structure makes LOS become vulnerable to angular rate disturbance around yaw(heading) axis of aircraft and allows camera to obtain images of only strip vicinity of target instead of rectangular coverage around the target even in moderate pitch lead/lag angle direction. These shortcomings, however, can be supplemented through the implementation of proper LOS scanning scheme suggested in this paper. Airborne EO/IR camera(AEI) is designed to obtain images of large area. Generation of pitch reference angular rate command considering predetermined trace of LOS projected on target(earth surface) and rotation of LOS from LL(Local Level) to gimbal coordinates can make sure LOS to scan properly. Simulation results show that the new scanning scheme ensures robust scanning even under aircraft heading disturbances and lead/lag pitch angle direction. This paper describes the new scanning scheme along with overall but brief introduction to the system formation of AEI, as well as simulation which enables us to verify and assess the effectiveness of the new scanning scheme.

No abstract

No abstract

No abstract