Development and evaluation of windscreen designs for high altitude balloons

Wind noise significantly limits the use of infrasound for ground-based remote sensing, but this problem is mitigated with the use of high altitude solar balloons due to the balloon drifting with the local air. However, to resolve the direction of arrival a long flight line is required to create sufficient separation between sen- sors, which increases the relative speed for the lower sensor. This method is currently being considered as a means for exploring the interior of Venus, which the higher shear and air density will amplify this noise. Consequently, the current work reports on the development and evaluation of compact, lightweight wind- screen designs for use on high altitude solar balloons. This paper presents laboratory, ground-based field testing, and a preliminary flight test of three new windscreen designs. Their performance is quantified with a measure of their wind noise reduction and attenuation of coherent sounds.