Risk Assessment and Experimental Light-Balloon Deployment of a Stratospheric Vertical VLF Transmitter

Abstract

This paper discusses the risks associated with an aerostat-supported stratospheric (unanchored) balloon mission equipped with a long vertical antenna and a very low frequency radio transmitter. The risks have been grouped into four main types and applicable mitigation methods have been presented to provide a sufficient level of safety and reliability to such a balloon mission. An experimental mission consistent with this analysis, based on the described theoretical VLF propagation approach, has been prepared and launched, and is operating at 14.2 kHz with a vertical antenna of a total length of 400 m and a total payload of max. 4 kg. The maximum altitude reached 29,164 m. The experiment’s signal has been registered in numerous locations in Europe; the results are compared with numerical analysis employing a hypothesis of an apparent transmitting frequency decrease with the rise of the transmitter’s altitude. The numerical analysis explains the behavior of the experimental signal and remains generally consistent with the hypothesis.

Insights on Polar Day Antarctica Radio Propagation Using Amateur Radio Beacons on Circumnavigating Balloons

“…Balloons have also been recently used to understand very low frequencies (VLFs) and their apparent frequency changes with changing altitudes [16]. While the utilization of pico balloons carrying WSPR transmitters has gained popularity among balloon and amateur radio enthusiasts in recent years [17,18], there is a lack of published literature on the propagation results obtained from these balloon flights.…”