Hurricane navigation with a small UAV: Practical experience and future strategies

The Aerosonde UAV was conceived with the idea of penetrating a tropical cyclone (aka hurricane / typhoon). Since 1995 it has participated in a number of field trials with the goal of penetrating tropical cyclones (1998 and 2002 Australia, 1999 and 2001, Japan, 1999-2005 Taiwan, and 2001, 2005 Wallops Island Virginia). Over the years improvements were made in engine reliability, satellite communications, and navigation software, but the right opportunity had not presented itself. Finally in 2005 there were two spectacular successes. NOAA and NASA launched an Aerosonde from Wallops Flight Facility into Tropical Storm Ophelia. The aircraft navigated through the core of the tropical cyclone and returned safely. Just a month later an Aerosonde penetrated the eye of a category 4 typhoon near Taiwan. The aircraft performed semiautonomous navigation into and out of the storms. Some navigation results are presented along with possible future directions.