Gps L3 test 23sep08

18jan09

There was a gps L3 test on 23sep08. During the test the L3 signal was left on continuously. Time domain (voltage samples) were taken with the mock spectrometer during the test. The setup was:

mock spectrometer run at 172.032Mhz with a decimation of 21 giving a bandwidth of 8.192 Mhz
I,Q, 12 bits samples, 2 polarization data taken for about 60 seconds.
telescope sitting at az=285, za=10.
alfa beam 0 used. 1379 Mhz was the center of the rf band.
16K power spectra were computed and averaged to 40 milliseconds. 800 averaged spectra (32 seconds) were used for the plots/images.

Average spectra (32 seconds) (.ps ) (.pdf):

The top plot is polA, the bottom plot is polB
the freqeuncy resolution is 500 Hz.
The spectra is the median of the 800 spectra computed.

Dynamic spectra of polA (.gif):
Dynamic spectra of polB (.gif):

Each 16K spectra was smoothed and decimated down to 1024 pnts (8 KHz resolution).
The median bandpass was divided into each of the 40 msec spectra to flatten the image. The image shows changes from this average bandpass.
The solid horizontal lines in polA spaced every 12 seconds are a radar.

Processing: x101/080923/gps.pro

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