F35 Takeoff Noise at Winooski Post Office

   These two screenshots are from the same measurement of four F35s taking off, measured at the Winooski Post Office at the top of the traffic circle.  The ‘headline numbers’ are 114dB-C and 108dB-A.  The noise exceeds 100dB-C for about 15 seconds per jet at this downtown location.  The first screenshot is zoomed in on the 4 jets, I caught the first jet mid-flight at the beginning of the plot.  The first three jets were taken with C-weighting, the fourth with A.  You can see the rumble is attenuated following the peak of the A-weighted jet. 

   The second screenshot is the full plot that includes the vehicular noise of the traffic circle.  Where the noise rises and drops ten decibels is my switching from A to C to A weighting to illustrate the effect on lower frequencies that traffic generates. 

   The little 90dB 'triangle' around 14:44 is a commercial regional jet following the same flight path as the F35s, although apparently quite a bit higher elevation.  Why would a small regional jet attain a greater altitude over Winooski than powerful F35s??

Click on each screenshot to enlarge.