3-D visualization of electrostatic fields on a helicopter in flight

Aircraft in flight typically charge via electrostatic processes; this charge is the source of measurable electric fields. Nearby objects may perturb this field, so there is interest in developing electrostatic sensors that can sense nearby objects like power lines by measuring their effects on the field. A major obstacle to developing these sensors is that there are often large variations in the field due to other causes. The problem is particularly difficult for helicopters where the rotating blades cause large periodic variations in field intensity. The Army Research Laboratory (ARL) has developed a model that predicts these self-generated variations so they can be cancelled out and the smaller variations from other objects can be seen. A new code is presented that was developed at ARL for visualization of the complex fields present on helicopters. The fields are different on virtually every part of the aircraft and vary with both the main and tail rotor positions. The code combines a large number of different quasi-static calculations in a single animated display where field strengths are "painted" as textures on the aircraft model. The code allows the user to view the time variations from any viewpoint in stereo. The stereo viewing is very important for clear and easy interpretation of the complex field patterns produced by the models.