observing the sun



    This page has the 12meter sun observations and  tests to make sure things are linear on the sun.

Current settings to use on the sun

30nov21:current values I'm using. may not guarantee no compression.

18nov21: make a map of the sun

    On 18nov21 2 maps of the sun were made  with the 12meter and the mock spectrometers.
The setup was:

Processing the data:

Looking at strips through the center of the sun:

Map 1 strips in ra and strips in dec through the sun (.ps) (.pdf)
Map 2 strips in ra and strips in dec through the sun (.ps) (.pdf)


processing: x101/211118/stripssun.pro

24nov21:does the if/lo, mocks compress while on the sun?

    On 24Nov21 a test was done to see if the control room if/lo and mock spectrometers compress while tracking the sun. The udc was not tested (see previous udc measurements).

The setup was:

The table shows the 3 sequences that were done

mockRms with attn if2 0 0
if2pwr attn 0,0
polA , polB

off sun
50 a/d counts
-46.25, -48.15 dbm

On sun
100 A/D counts
-28.41, -29.71 dbm

On sun
200 A/D counts
-28.23 , -29.74 dbm

Previous  sun measurements used mock rms= 100counts and if2pwrMeter=-28dbm.

Processing the data

    We want a single total power values for each attenuator setting by pol and freq band.

Looking at the compression.

    If the system if/lo or mocks compressed, then the measured power step  should be less than 1db as the power increased (the attenuation decreased).

The first plot show the power vs 1db steps (.ps) (.pdf)

This showed that the attenuator steps were probably not exactly 1db.
PolB showed a decrease in step size as the attenuation approached 0db, but it showed this even off the sun when the power  was 20db lower than on the sun.

Compare Each 1 db step for the 3 mock rms levels.

 The plots compare the 1db atten steps for the 3 different rms settings. (.ps)   (.pdf)


processing: x101/211124/lintest.pro, lintest2.pro

12meter page