Both during and after Hurricane Bonnie's onslaught, analysis of the storm was extensive; it was deemed the most observed hurricane in history. When examined with Tropical Rainfall Measuring Mission (TRMM) satellite imagery, it was discovered that peak cloud tops surrounding the eyewall rose into the atmosphere, twice as tall as Mount Everest. This was the first time that TRMM had observed such a tropical cyclone structure, according to co-developer of the Saffir-Simpson Hurricane Scale, Bob Simpson. The storm was also used for collection of tropical cyclone research data. For the first time in the Atlantic, a fleet of aircraft investigated the storm's upper-levels, while other aircraft flew into the low- and middle-levels. A record of over 500 parachute sensors were dropped into the storm while it was active. Each costing $600 (1998 USD), they sent storm data to research centers via Global Positioning System.