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KeplerBoy 1 days ago [-]
Obviously insanely impressive, but I have some doubts about the actual pervasiveness of recorded aircraft noise in casual videos.
The example with two prop planes seems a bit contrived (not that it wouldn't work with jets, they are usually just much higher up and have less distinct fundamental frequencies). Having two planes within audible range (stated at ~10 km slant range in the video) is a pretty rare event for a lot of places, even in the US with widespread general aviation.
mikewarot 20 hours ago [-]
I took a video I shot back during Covid, stripped the audio, and threw it into a quickly composed GNU Radio flowgraph, and it sure looks like there are a few doppler curves in it, and you can almost hear a propeller plane around 150 seconds in... I live near a small airport, it was a nice sunny day, so someone surely was out flying.
I need a better spectrograph to be sure.
xpct 7 hours ago [-]
This showed up on my YouTube feed.
One thing I think is still true, is that you can't completely algorithmically automate this and will have to extract the doppler curves manually from more noisy spectrograms, using your own judgement on what counts as a proper signal or not.
Would be curious to hear from someone who does similar audio analysis.
The example with two prop planes seems a bit contrived (not that it wouldn't work with jets, they are usually just much higher up and have less distinct fundamental frequencies). Having two planes within audible range (stated at ~10 km slant range in the video) is a pretty rare event for a lot of places, even in the US with widespread general aviation.
I need a better spectrograph to be sure.
One thing I think is still true, is that you can't completely algorithmically automate this and will have to extract the doppler curves manually from more noisy spectrograms, using your own judgement on what counts as a proper signal or not.
Would be curious to hear from someone who does similar audio analysis.