Navigation Through Fog: A Mathematical Analysis of Folder Path Propagation
Abstract
The problem of navigation through fog was brought tragically to the fore during the summer of 1999 when John F. Kennedy Jr.'s plane crashed into the Atlantic off the coast of Martha's Vineyard. The key factor here was the inability to determine the vertical direction due to the lack of visual cues. Less catastrophic, but of more concern, are frequent delays caused by fog at America's major airports. It is estimated that one major air package carrier alone incurs yearly costs measured in millions of dollars due to delayed or rerouted flights caused by airport fog conditions. Such delays would not be necessarily if alternatives to the current methods of handling fog conditions were available. The current method of coping appears simply to involve reducing the rate of aircraft arrivals and departures such that collisions are avoided. However, such an approach does not avoid the problems encountered by John Kennedy Jr., nor does it curtail the possibility of collision with obstacles on the runway. (Incidences of wildlife appearing on runways under low visibility conditions have also been noted in the past.) Though several methods for improving the ability to see through fog have been attempted, the one of interest in this case involves the use of stereoscopic vision devices coupled with laser illumination and realtime image deblurring software. But a fundamental question remains as to the capabilities of this technology when confronting real world fog environments. While models of fog scattering properties exist, the propagation models for use of these models have often relied on Monte Carlo analysis of scattering by fog particles. This analysis is usually incomplete - it cannot adequately address the spatial and angular structure of the radiation that reaches objects within the fog volume and the return signals from objects in the fog. In particular, if corner reflectors were mounted at the sides of the airways, could such reflective objects be viewed through the f7
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2002
- Accession Number
- ADA423580
Entities
People
- David H. Tofsted
Organizations
- United States Army Research Laboratory