1. McNeese LA-ACES Group Sound Experiment
Columbia Scientific Balloon Facility
Palestine,Tx May 2007
Results
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2. Overview Flight Objectives Results Conclusion Special Thanks Velocity
Tropopause to Stratosphere information
Spectrograms
Stratosphere information
Conclusion
Special Thanks
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3. to measure the wavelength of the sound wave.
There is an arrival time LAG between the two microphone, that we can use
to measure the wavelength of the sound wave.
Sound with a simple sinusoidal signal
With a fixed frequency of 500 Hz
Microphone 1
Left channel
Microphone 2
Right channel
9 cm
Speaker
MP3
Digital Recorder
Stereo HQ
(44100 Hz Sampling Frequency)
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4. Results from our experiment (room temperature, 21 Celsius, sea level)
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5. Flight Objectives Primary Objectives Secondary Objectives
Record environmental noise
Measure the velocity of sound as a function of altitude
Design a payload that will run and protect our experiment
Secondary Objectives
Finish extracting and examining our data
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6. Velocity
The standard atmosphere data curve is based on calculations using average atmosphere temperatures (v=( T)m/s)
In Tropopause T is constant (-57C)
Sources of error for our experiment could be that the tropopause is not an ideal gas or our experiment was not reliable in this area of the atmosphere.
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7. Tropopause to Stratosphere Transition
The sounds are from the Stratosphere to Tropopause descent.
The waveform shows the entire Tropopause to Tropopause ascent and descent.
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8. Spectrograms BLayer
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9. Spectrogram Stratosphere
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10. In the Stratosphere
After zooming in on the sound in the stratosphere we see a nearly perfect sine wave with little or no other noise.
This tells us that there really is no wind at that height.
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11. Conclusion The experiment ran almost exactly as we predicted.
The measured velocity followed closely the theoretical model up to the tropopause.
The tropopause was the only section where we could not figure out what happen, because it didn’t follow the model or our predictions.
The experiment ran the duration of the flight and lost no data.
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12. Special Thanks Dr. Santostasi Mr. Archer NASA Staff La-ACES groups
LSU organizers
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