10jan19:327 hires azimuth swings


Processing the data
Dynamic spectra of the azimuth swings
Average/PeakHold spectra for each az swing:
The azimuth dependence of all the birdies
birdies with no az dependence (coming from dome)
birdies with common az dependence
look for ionosonde transmissions in 327 receiver,.,
Previous 327 azswings:

Introduction (top)

    It's been almost 3 years since a hi res azimuth swing has been done with the 327 MHz receiver to check for rfi. Two azswings  (cw then ccw) were done on 10jan19 starting around 15:20. The weather was clear during the swings (no lightning).

The setup:

Processing the data: (top)

Dynamic spectra of the azimuth swings:  (top)

    Dynamic spectra were made for each of the  azimuth swings showing spectral density plotted against azimuth and frequency. The plots were aligned so that azimuth always increased bottom to top (so the swings from 270 to -90  were flipped). At the bottom of each image is a peak hold spectra (maximum in each frequency channel) for the entire spin. 

CW spin
CCW spin

Plots of the rfi

Average and peak hold spectra:

The first plots show the average and peak hold for each azimuth swing (.ps) (.pdf)

Azimuth dependence of individual rfi frequencies.

The second set of plots has the azimuth dependence of 143 different rfi frequencies (.ps ..12Mbytes) (.pdf 4.7Mbytes)

Rfi with no az dependence (from azArm, or dome):

The third set of plots shows rfi that has little azimuth dependence (.ps) (.pdf)

Rfi with common azimuth directions.

The 4th set of plots shows rfi that has a common azimuth direction:

Combs seen in the 327 band:

Average spectra versus freq with combs flagged (.ps) (.pdf)

ionosonde transmitting (top)

    The ionosonde was transmitting on 15 minute intervals during the 327 Mhz azimuth swings.
A third clockwise swing was running when the 16:00 ionosonde  ran.  The ionosonde transmissions are:

    The azimuth was moving clockwise at .4 deg/sec.

    How fast was the ionosonde frequency stepping at 325 MHz? If via harmonics

Depending how the harmonics are created, there could also be other freq steps.

A dynamic spectra was made for the time around 16:00  (.png)

Looking at 10 seconds after 16:00 there seems to be something from 309 to 322 Mhz, but the spacing is less than a Mhz.
To Get a better idea whether the ionosonde causes trouble in the dome receivers, we should probably dump data fast, and look for the 140 usec rf pulse repeating itself at the 25 ms ipp.

processing: x101/190110/azswing327/ionosonde.pro

Summary (top)

processing:  x101/azswing327/190110/327azswing.pro