azswing 800 Mhz rcvr 29nov10

29nov10: az swing looking at 700-800 Mhz band (top)

2 az swings were done on 29nov10 looking at the 700-800 Mhz band.
The setup was:

Processing the data:

The .1 second spectra were averaged to 1 second.
The azimuth positions were interpolated to the center of each avg spectra.
A median spectra was computed for each swing. The total power for each spectra was computed and then the lowest most 20% was used to compute the median.
A robust polynomial (1st order) and harmonic (43 terms) fit was done to the 700-800 Mhz data. This fit was then used to normalize each spectra of the az swing.
The rfi peaks were selected interactively by over plotting all the spectra for a swing.

dynamic spectra show the spectra power vs azimuth position. Pol A and pol B have been averaged together.

The black trace at the bottom of each image is an overage spectrum over the entire swing.

The second set of plots show the azimuth dependence of individual interference (.ps) (.pdf):
A list of the frequencies are:

Freq	Peak Val(Tsys)	inside Dome	Notes
736.96	5.	no	this is the 734.7-793.3 Mhz rfi It is part of the FCC block B lower 700 Mhz band auctioned off on 18mar2009. see: 700Mhz band auction for PR
740	0.05	no	Not a large az dependence, but the CW, CCW bumps track exactly so this is outside of the dome.
744.54:	0.1	yes	Constant with no azimuth dependence.
747.08	0.2	no	CW,CCW swings overlay each other so outside the dome
750	0.8	no	probably the DC spike from the mock complex sampling.
754.03	.04	?	does not repeat in azimuth but is probably time variable so can't say if in or out of the dome.
775.22	0.15	no	CW,CCW swings overlay each other so coming from inside the dome.
789.25 793.74	4.5	no	This is the video and audio carriers for analog tv channel 67. This was seen after the low power station in pr turned off. It may be from the Dominican republic. The azimuth peak has changed: 29nov10 about az=0 25aug09 -46deg az So maybe we have something different.
791.37	0.15	no
801.24	0.08	no

The alfa motor controller and the cameras were probably on for this test. I don't know if they were causing problems at this time.

chan 67 analog is still present although it's direction has changed since aug09
The 734.7-793.3 rfi is lower block B. Probably should see if this is coming from prt in san juan.

processing: x101/101129/800azswing_wb.pro