Alfa (p2030) 12 second compression is faa radar.


     The alfa pulsar search (p2030) saw strong 12 second periodicity's on 01aug05.  They sample data at 64 usec using 100 Mhz (1370 to 1470)  with 256 channels. They add the polarization's before storing the data. I looked at one of the 2 gb files (about 130 seconds of data) where the problem was the worse: p2030.G35.21+01.00.N.wapp1.53584.0004. This contains pixel 0 and pixel 1 (i ignored pixel 1 since pixel 1b is dead). The plots show the total power versus time (.pdf):

The next plot shows that the baseline change is across the entire 100 Mhz band.:     This data was taken at an azimuth of 340 degrees and a za of 16.6 degrees. This is one of the azimuth's that showed a large compression when azimuth swings were done to check the  azimuth dependence of the compression in the alfa receiver caused by the faa radar (description of the test, plots of compression vs az (.ps) (.pdf) )
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