Michael, Krishna

There has been very little wind since we have had BRS-2 up and running so I'm posting some interesting data from the earthquake last night. The attached ASD plot, shows the spectra from the Mag 6.0 earthquake in Japan last night. The data set was about 10k secs and centered around peak of the earthquake.

The first blue line is the BRS-2 raw rX data showing the resonance at 7.6 mHz. The green line shows the BRS rX OUT from the filter banks. The third shows the ground seismometer's Y measurement showing the big peak at 50 mHz from the earthquake. Notice that there is absolutely no such signal in the BRS-2 output. This is because the acceleration coupling is very small as shown by the fourth line. Also, the real angular signal expected from the surface waves from this earthquake were not big enough to be resolved by BRS-2. We need a bigger earthquake to resolve the angular motion of the ground from them.

I've also attached the matlab code for this data set.