Talk:Effects of altitude on Earth's electric field and the reception of natural very low frequency (VLF) radio events

Data and Analysis
It looks like launch time occurred at 12:10 PM, correlated with minute 39 of the audio recording.

The pod reaches a maximum height of about 20000 feet, or 6km, which means the balloon never even left the troposphere. Maximum height occurs at 13:02 PM, and it looks as if we start seeing a decline in sferic activity once the balloon pops. However, during the descent there is a large amount of NR time, corresponding to a large amount of physical noise, which would account for the inability to successfully record as much sferic activity.

The dip in sferics in the region 12:53 PM to 12:57 PM is also accompanied by a spike in NR time. However, from 12:58 PM until the pop at 13:02 PM the sferic activity is notably lower than previous readings. This could be simply a result of the variance in sferic activity (as noted by the large fluctuations in sferic readings, even during periods of calm) or it could signify that we don't have the launch time properly time stamped.

While there is a rather smooth decline in sferic activity during the descent of the pod, and it is tempting to correlate this with some sort of atmospheric effect, I am more inclined to note the high levels of NR time during the descent. Hence there is likely simply a large amount of banging around during the descent which interferes with successful sferic measurement. However, noting that the entire end of the audio file include roughly no sferics and relatively low NR time, signifying that at ground level it is difficult to detect sferics, justifying our search for the in near space.

Also, we can use the period from 12:11 PM to 12:51 PM, where there is high sferic activity and low NR time, to find some sort of average of sferic activity. This is not terribly groundbreaking data, but it gives a good base for future readings.