Weather balloon flights as a method to record the stratosphere

Weather Balloon Flight 3

Coming soon! Waiting for conditions in the Jet Stream to calm down. Aiming for a flight late November/early December 2019.

Weather Balloon Flight 2 – 6th October 2018.

Finally! After 6 months of delays caused by strong winds in the jet stream and the higher stratospheric winds I was eventually able to carry out a second balloon flight. As part of my research at the University of Technology Sydney I'm still attempting to place my microphones away from all sound and record a natural silence in the stratosphere using a weather balloon. This flight reached an altitude of 33.5km, just above the ozone layer, half way into the stratosphere and 1/3 of the way to space. I made some improvements based on the outcomes of the first flight (see below) with all adjustments to the payload and recording system making for an improved and great sound recording, along with some impressive visuals from a GoPro. A 360 camera was also used but stopped filming on ascent at an altitude of approximately 25km, the internal and external batteries still held plenty of charge so it’s thought the extreme cold affected the function of the camera. Nonetheless, some great 360 footage was also captured.

This improved recording raises new research questions within the weather balloon recording method and general approaches to field recording, including the notion of recording soundscapes from above as opposed to the usual within and the idea of using both free flying balloons and those tethered to the ground to do so. I am still to complete one more flight within this body of research to advance the technique further.

Below are some stills form GoPro footage that show various stages of the flight form launch, burst point and landing. These are all raw and unedited straight from the footage but you can see pieces of the balloon after burst, then an upside down shot towards space of the leftover balloon and parachute as the load begins the initial fast and violent decent, the last pic shows the parachute falling into frame about to hit the ground.

Thanks again to Robert Brand for his ballooning expertise.

Weather Balloon Flight 1 – 4th March 2017.

I wanted to place my microphones in the stratosphere to record what may or may not be happening at high altitudes, hoping to record as close to a natural silence as possible. To do this I came to the idea to use a weather balloon as a sound recording technique. To my knowledge, the use of a weather balloon flight as a recording technique using acoustic microphones had not been attempted before my first launch in March 2017.

As part of my doctorate studies at the University of Technology Sydney, I use sound recording to try and capture the most base level sonic layers in our soundscapes, independent of all the primary and obvious sounds of life. In doing so, I record the discrete and distinct acoustic properties of landscapes illuminated by only by the constant and most subtle geographic sounds that always occur. It is a sound that can only be heard in the quietest natural environments, a very rare and difficult to find sound found only in remote places that takes us back to a time before life. I invert our soundscape to look below the noise to a hidden and discrete sound that is all around us but smothered by primarily human sound.

I take the same method and approach of room tone recording for film production to our natural environments. As with a ‘clean’ room tone recording, I attempt to eliminate all Anthrophony (human sound) and Biophony (wildlife sound), and work to limit Geophony (geographic sounds of wind, rain etc.) as much as possible. To capture an uninterrupted clean recording of the sound I chase, I try to avoid even the sounds of insects and vegetation moving in the wind.

I use only standard acoustic microphones and record sound that is happening within our human hearing range.

However, this base level sound is very difficult to capture in the way I aim for on the ground because our world is a noisy place. Anthrophony is far reaching, animal sound is all around and limiting the constant natural geophony is difficult.

I then came to the idea to put microphones in the sky.

Given a weather balloon has no engine and makes no sound of note, it was thought this would allow me to record from the ground up towards a natural silence, the best method to get away form all sound on the ground and record a journey in to the stratosphere. There are numerous examples of filmed weather balloon flights using lower quality internal camera microphones where sound quality is not considered, but to my knowledge there are no attempts to record an entire flight in high definition sound using quality sound equipment.

This  flight was on the 4th March 2017, 2.5 hours long and reached a height of 33kms, a third of the way to space and well in to the stratosphere, just above the ozone layer. This flight largely functioned as a test flight and although there are aspects of the sound recording method to be improved upon, I did get some great and fascinating sound that is a big step closer to the quality I'm aiming for.

This is the most extreme, creative and expensive field recording technique I've ever used and will continue with. The next flight is March 2018.

Thanks to Matthew Stuart for his skills in designing the housing for the recorder and microphones. Thank you to Robert Brand for his weather balloon expertise.

Here is a collection of stills from a video placed on the balloon payload of various stages of the flight, including the final pieces of the balloon at burst point...