Weather Avoidance Sensor Systems for Unmanned Aerial Systems

This research program will demonstrate the feasibility of enhanced approaches to unmanned aircraft weather avoidance using a combination of organic weather radar and electro-optics. In manned aviation, the pilot with his eyes in the cockpit complements Fleet Numerical Meteorology and Oceanography Center - provided weather products by considering visual cues along with the information provided by the onboard weather radar. Visual cues are vital tools for pilots especially when cross verification a radar and evaluating hazard clearing maneuver options. Weather radar has limitations due to resolution, ambiguities, shadowing, and the inability to detect ice or clouds. It is only capable of detecting precipitation droplets, e.g., rain, wet hail, wet turbulence, and to a lesser extent dry hail, ice crystals, and dry snow. It does not detect fog, clouds, clear air turbulence or wind shear, sand storms, or lightning. Weather radar displays depend on signal returns, and heavy precipitation may conceal weather behind an intervening cell due to signal attenuation. Areas behind closer strong precipitation may be misinterpreted as clear areas. For this reason, the weather radar by itself should only be considered as a tool to be used for weather avoidance and not weather penetration