180727-180803 looking at the sun

Jul18

background
What we did
Making the plots and dynamic spectra
the plots and dynamic spectra
Measuring S11 from the hfCtrl room.
Summary


Background:

    There is an interest in developing a solar radar at AO. This could possibly use the highest band of the hf transmitters (20+Mhz). A test was done to see if we could detect the sun using the 8.175 MHz dipoles.

What we did:

Making the plots and images:

The dynamic spectra and plots:

date
Dynamic
spectra
Plots
description
180727
18:30-24:00
(.png)
27_30 (.ps) (.pdf)
  • telescope moving the entire times
  • median noise floor about -85 dbm in 10KHz rbw
  • plot notes:
    • page 3: red * show where azimuth was not moving. n spectra for entire set
180728
00:00-24:00
(.png)
180729
00:00-24:00
(.png)
180730
00:00-08:24
(.png)
180731
09:55-13:00
(.png)
31Jul18 (.ps) (.pdf)
  • telescope stationary for most of run.
  • median noise floor all data:-82dbm
  • median noise floor 11.3 to 11.56: -90dbm
  • plots:
    • page 1: avg and median bandpass
      • all data (black,red)
      • 11.3 to 11.56 (green,blue) when rfi was lowe
    • Page 3. az pos,torques
      • at 11.5 motor currents low for 15 minutes.
      • 100KHz totPwr -75dbm -> -90dbm .. but doesn't got all the way down to -105dbm (value at 10.7 hrs).
180801
11:20 - 13:20
(.png)
01aug18 (.ps) (.pdf)
  • telescope stationary till 13:12
  • median noise level (-87dbm @ 8.175Mhz)
  • Plots:
    • Not sure what caused the power drop around 12.7 hours
180802
11:15 - 13:15
(.png)
02aug18 (.ps) (.pdf)
  • telescope stationary for entire time
  • median noise level (-87 dbm @8.175Mhz)
  • extra noise present for entire time
180803
11:05 - 13:00
(.png)
03aug18 (.ps) (.pdf)
  • telescope stationary during transit
  • median noise level (-105dbm @ 8.175MHz)
  • Used emergency stop button to try and keep warming current off. Looks like it worked
  • Plots:
    • page 2: the purple trace shows the bandpass shape when the strong motor rfi was present.
      • The fwhm of the trace is about 100KHz.
      • The signal is centered around 8.29 Mhz rather than 8.175 MHz.
      • it falls off by 10db in about 3 octaves
  • The last page shows the azimuth dependence of the motor interference
    • the radial dipole is at an az of 60 (or 240) deg.
    • The minimum coupling is when the azimuth is aligned with the dipole.

Measuring S11 from the hf ctrl room

    On 02aug18 S11 for the 8MHz radial dipoles was measured from the hfctrl reflected power panel (The signal output)

the Plots show the S11 results (.ps) (.pdf)


Summary:

processing: x101/180728/hfsun.pro, 180731,0801,0802,0803/hfsun.pro


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