Comparing Performance of Two Generations of Radiosondes in a Tethersonde Application

The Student Operational ADRAD Project (SOAP) is a summer undergraduate research class focusing on observation technologies and their application to research problems. In Summer 2011 a tethersonde capability was developed utilizing the iMet 1 radiosonde and an iMet 3150 ground system. In Summer 2012, a number of surplus Vaisala RS-80 sondes were obtained as well as a Vaisala PP-11 radiosonde processor. Using a readily available ham radio receiver covering the nominal 403 MHz frequency of the sondes, and interfacing the radio to the PP-11, a ground capability has been developed suitable for tethersonde usage. The simultaneous usage of iMet 1 and RS80 sondes provides an opportunity to compare the performance of these two systems separated by approximately two decades in technology in the parameters of temperature, humidity, and pressure. Further, it provides an opportunity to explore some of the common behaviors seen in tethered applications, including the difference of values obtained in ascent vs. descent even in rapid cycling of the tethered blimp. This behavior was noted in the initial deployment of the 2011 system to the Texas A&M Cloud Forest REU in Costa Rica. Intercomparison findings are given, as well as information on the possibilities for developing an inexpensive tethersonde system based around surplus Vaisala RS-80 sondes which are frequently available on sources such as Ebay. Such a capability could have usage not only in research and higher education, but also in stimulating Science, Technology, Engineering, and Mathematics (STEM) activities in K-12 settings.