SDRangel screenshot controlling one of our 26 meter antennas during the solar eclipse

[Lamar Owen]

So as to not continue hijacking the focus thread, here's a new one for
the subject of using SDRangel, specifically for how I am using SDRangel.

Attached is a screenshot of all three monitors of my S-band SDR system
that was controlling our 26 West antenna on April 8.  I was wanting to
do some analysis of the raw data before posting this, but it seems timely.

The three monitors are set up in a upper left, upper right, and lower
right pattern, with the lower left not being occupied.  So the
screenshot looks a little odd.

Going over the screenshot, the upper left monitor has our site webcam
view on it, showing the 26 West antenna's position.

The upper right monitor has a remote desktop session to a control PC
located at the antenna that is running the Yaskawa SigmaWin 7 program to
monitor the four drive servos (two on the lower X axis and two on the
upper Y axis).  Behind the remote desktop session is a terminal running
my Python rotcld server code that is logging output of commanded and
current positions with timestamps along with internal PID motor control
data points; I save this log as a CSV for later analysis of pointing
error and tracking oscillation.  The desktop background image is from
the HI4PI 1.42GHz all-sky survey; https://arxiv.org/abs/1610.06175,
specifically the top image in the webpage at
https://www.mpifr-bonn.mpg.de/pressreleases/2016/13 (note that full
datacubes of this survey are available for download!).

The lower right monitor shows the SDRangel program. The subwindows in it:
1.) Upper left: basic SDR frequency and parameter control;
2.) Upper middle: FM demodulator plugin that I use to listen to GPS
COSPAS/SARSAT subcarriers (listening to Radio Algeria International over
a GPS satellite transponder when the satellite is over the Carribean is
a trip; you can listen to this yourself at
https://nebula.pari.edu/index.php/s/sJW9YfrXG5fCKTW if you're so inclined);
3.) Right hand subwindow, behind the Radio Astronomy channel plugin: the
raw SDR spectrum and waterfall;
4.) Right hand subwindow in foreground: the Radio Astronomy channel
plugin, with the spectrometer graph collapsed and the radiometer graph
expanded.  The secontions of the radiometer graph reflect, in order from
left to right, gong to cold sky near the north celestrial pole, going to
Cygnus A, slewing over to the Moon, then the Sun, then the Moon, then
the Sun again, then through the Moon to cold sky and Cygnus A, back to
the Sun, then the Moon, then the Sun, then the Moon, cold sky and Cygnus
A, back to the Moon (got a brief glimpse of the Sun), a last calibration
against cold sky and Cygnus A, then the Sun during the eclipse up to the
time of maximum eclipse.  The graph has a distinct knee in ti due to the
beamwidth being smaller than the Sun (0.359 degree 3dB BW) and the radio
Sun not being a circle; as the moon obscured the Sun and the resulting
crescent appeared to rotate, the flux change reflects the presence of
the crescent; again, I've not fully analyzed this data, nor have I had
opportunity to fully calibrate the plugin, which has a lot of controls
I'm not yet using....;
5.) Lower left subwindow: the Startracker feature plugin, showing the
track of the Sun across the sky;
6.) Last by not least, partially obscured by the Startracker, is the
rotator control feature plugin subwindow showing its settings.

The SDRangel documentation for each of these plugins:
Radio Astronomy channelrx:
https://github.com/f4exb/sdrangel/blob/master/plugins/channelrx/radioastronomy/readme.md
Rotator Controller:
https://github.com/f4exb/sdrangel/blob/master/plugins/feature/gs232controller/readme.md
Star Tracker:
https://github.com/f4exb/sdrangel/blob/master/plugins/feature/startracker/readme.md
Satellite Tracker:
https://github.com/f4exb/sdrangel/blob/master/plugins/feature/satellitetracker/readme.md

Building SDRangel on Linux from source:
https://github.com/f4exb/sdrangel/wiki/Compile-from-source-in-Linux

Brief overview of the interface and quick start:
https://github.com/f4exb/sdrangel/wiki/Quick-start

Note that I have ZERO experience building or using SDRangel on Windows
or Mac; I'm using it on Linux only.

[Marcus D. Leech]

I'm hoping to do a write-up of our control system in the next month or
two.    A requirement was scriptability, so GUI bits have
  been slow to emerge.   I did "abuse" Gnu Radio to build a little app
for manual jogging, that uses the polar-plot widget to
  show az/el.    Actually, similarly, I built a Gnu Radio app to
monitor the power consumption of the motors -- I've got a current
  probe on each of the 240VAC power feeds to the motors, and these are
"read" with a cheap USB audio dongle -- these current
  probe clamp-ons were terminated in a 3.5mm audio plug, so, I thought
"what the hell, let's try this".  Works like a charm!

The piece of code that interfaces to the motors directly is a server,
necessarily written in C++, because the library provided
  by TekNic is a C++ library.  That server is "dumb".   It knows
nothing.   The actual applications are written in Python, and I'm
  considering writing yet-another domain-specific language for doing
the dish-motion side of observations.    Right now,
  we only have the two applications--the manual jogging app, and a
"slew-to-and-track" app.  But there are other observing
  doctrines that one might contemplate, so I want do do a big step back
to see what the best approach is.