The Rise and Fall of the Jimsphere: A Historical Perspective and a Look Forward

Development of the Jimsphere wind sensor began in early 1960s when it was realized that the Rawinsonde technology as well as the “ROSE” balloon were aerodynamically unstable in supercritical Reynolds regimes, and could not provide accurate measurements of small-scale motions.

Over the next few decades, the radar-tracked jimsphere combined with the Rose data processing program evolved as the standard for making high-resolution wind profile measurements in support of national programs including space shuttle and other space and missile launches. During this period, wind profile climatologies were developed that are still used for vehicle performance analyses as well as new design evaluations.

With the advent of GPS based tracking, the quality of the data produced by the jimsphere systems no longer deteriorated with range. Until recent years, jimspheres were in wide use to support space launch operations. Recently, however, new developments have indicated such high resolution measurements by balloon systems have limitations, and more course measurements made directly overhead such as those provided by Radar Wind Profilers are more representative of the actual conditions a launch vehicle experiences. This is especially true considering the Wind Profiler can provide measurements in just several minutes.

This presentation will examine the performance of modern GPS jimsphere and GPS rawinsonde technology; and, contrast those with the performance of the NASA 48 mHz wind profiler that has been in operation since 2014 at Kennedy Space Center.