The Balloon Ring: A High-Performance Low-Cost Instrumentation Platform for Measuring Atmospheric Turbulence Profiles (Postprint)
Abstract
Balloons, similar to those used for meteorological observations, are commonly used to carry a small instrumentation package for measuring optical turbulence in the atmosphere as a function of altitude. Two temperature sensors, one meter apart, measure a single point of the temperature structure function. The raw data is processed to provide the value of cr2, and the results transmitted to a ground receiving site. These data are converted to the index of refraction structure constant, Cn2. The validity of these measurements depend on the correctness of a number of assumptions. These include local isotropy of the turbulence and the existence of the Kolmogorov inertial sub range, and that the data is not contaminated by the wake of these ascending balloons. A variety of experiments on other platforms, and in the laboratory, demonstrate that the assumptions upon which these balloon measurements are made are not valid for a large percentage of the flights. In order to collect data whose interpretation did not require preconceived assumptions, the balloon ring instrumentation system was developed. The ring is 28.5 meters in diameter, with a crosssectional diameter is 14 cm. The ring is hung just below the balloon, so that the wake goes through the center of the ring, and the sensors are mounted tangent to the circumference of the ring.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 22, 2009
- Accession Number
- ADA502790
Entities
People
- Alastair Black
- Demos T. Kyrazis
- Don G. Black
- Frank D. Eaton
- Wiley Black
Organizations
- Air Force Research Laboratory