This paper proposes vision-based techniques for localizing an unmanned aerial vehicle (UAV) by means of an on-board camera. Only natural landmarks provided by a feature tracking algorithm will be considered, without the help of visual beacons or landmarks with known positions. First, it is described a monocular visual odometer which could be used as a backup system when the accuracy of GPS is r...

The consideration of safety issues in the operation of helicopters involves the capability to perform emergency descending maneuvers through the autorotation principle when the engine is no longer supplying power. When comparing manned and unmanned helicopters, the lower rotor inertia of UAV configurations makes this functionality even more challenging for the pilot since more accurate timing a...

The palace of Ibn ‘Abbād has long been the subject study by numerous specialists, amongst whom its possible location considered to be current site Reales Alcázares Seville (Royal Palace and Fortress Seville). results derived from archaeological interventions carried out in several sectors this palatine complex have led us undertake a review all those studies that dealt with issue, which we must...