===== Telescope information =====

The ARC 3.5m telescope is controlled using the [[https://www.apo.nmsu.edu/mainpage/tui/tui_intro/|TUI software]],
which is software written in Python using a Tk graphical interface.

The telescope can also be controlled with command line commands and scripts, which
can be run through TUI. TUI includes some built-in scripts, but users can also provide
their own.

==== How To Track Solar System (Or Otherwise Moving) Objects ====

Steps 1 and 2 are advance preparation before your observing run.

1) Get raw ephemerides from JPL Horizons.  These are more accurate than our in-house ephemeris program can provide.  Go to the [[http://ssd.jpl.nasa.gov/horizons.cgi|JPL Horizons web interface]] and get these data for each target of interest: timestamp, astrometric RA and Dec (airless, in decimal degrees, J2000.0), RA and DEC rates. You can get additional info if you want, but those are the ones that we really need.  Example settings for JPL ephemeris:
    * Ephemeris Type [change] : OBSERVER
    * Target Body [change] : Saturn [699]
    * Observer Location [change] : Apache Point [705] ( 254°10'45.9E, 32°46'49.8N, 2891.2 m )
    * Time Span [change] : Start=2008-04-24, Stop=2008-04-25, Step=1 h
    * Table Settings [change] : QUANTITIES=1,3; time digits=SECONDS; angle format=DEG; refraction model=REFRACTED; skip daylight=YES; extra precision=YES
    * Display/Output [change] : default (formatted HTML)

Then Generate Ephemeris, which outputs something like:

<code>
Date(UT)HR:MN:SS R.A._(J2000.0)_DEC. dRA*cosD d(DEC)/dt
$$SOE
..... Daylight Cut-off Requested .....<
2008-Apr-24 02:00:00 C 154.3057447 12.5867617 -2.52 0.61
2008-Apr-24 03:00:00 A 154.3050264 12.5869290 -2.52 0.60
2008-Apr-24 04:00:00 154.3043103 12.5870917 -2.51 0.58
...
..... Daylight Cut-off Requested .....<
$$EOE
</code>

2) Write a script to convert the ephemeris numbers into the correct command
syntax. The BIG, IMPORTANT difference is that JPL gives dRA and dDec in
arcsec/hour, whereas our software wants deg/sec. That means YOU HAVE TO
DIVIDE THE SPEED BY 12960000 or you will get no data and track the
telescope into the ground.  It's useful to make a file with multiple commands, each one marked by a
timestamp so as to pick a command depending on what time one actually
issues the slew command. Here's some example slew commands:

<code>
tcc track 136.72666,  17.43467, -0.00000146,  0.00000046 Fk5=2000.0 /Rotangle=0.0 /Rottype=Object
tcc track 136.72666,  17.43467, -0.00000146,  0.00000046 Fk5=2000.0 /Rotangle=108.5 /Rottype=Object
tcc track 136.72478,  17.43524, -0.00000146,  0.00000046 Fk5=2000.0 /Rotangle=0.0 /Rottype=Object
</code>

where the first four numbers are:  RA(decimal degrees),  Dec (decimal degrees), dRA (degrees/sec), dDec (degrees/sec), and rotation can be specified with the /Rotation=rotation, where rotation should be calculated as 90 - PA, where PA is measured N thru E.

From the JPL ephemeris example above, one line would convert to:
<code>
2008-Apr-24 04:00:00 154.3043103 12.5870917 -2.51 0.58
tcc track 154.3043103, 12.5870917, -0.000000194,  0.000000047 Fk5=2000.0 /Rotangle=0.0 /Rottype=Object
</code>

3) Slew to the planet with desired rate and rotation.
Notify the observing specialist that you are about to issue a
non-sidereal tracking rate to the telescope and get their permission to
do so before doing the following. If the slew rate is wrong it can cause
the telescope to slew too fast, and the observing specialist can stop
the telescope before it goes out of control. The telescope will not
automatically check your numbers! If in doubt, ask the observing specialist to
double check your numbers and they can issue the tcc track command for
you as well.

Paste your pre-prepared commands into the TUI Log window. When in doubt
about anything (if your offsets get tangled up, for example), reslew.
This is the motivation for making all those pre-prepared commands. They
**will** come in useful.

4) Take images often to see what's going on. This is just generally good policy. It should be safe to run the guider
even if you have a non-stellar tracking rate.

==== Some useful observing object catalogs ====


====  Exposure time calculators ====

[[https://github.com/jradavenport/jradavenport_idl/blob/master/apoexpcal.pro | Rough IDL exposure time calculator]]

Other exposure time calculators for the 3.5m? 

==== Useful Observing Resources ====


[root@astronomy pages]# vi start.txt
[root@astronomy pages]# vi 3.5m.txt 
[root@astronomy pages]# vi tui.txt 

==== TUI information ====

Some (probably obsolete!) information about building TUI from source
on a Linux machine.

=== Python dependencies for linux users ===

TUI has strict python dependencies.  Many linux users have problems
displaying guider or slitviewer images because they have the wrong
version of one or more packages.  Even if TUI is built correctly,
running it from the wrong directory might result in a different
package being loaded.  Since individual linux and python setups can
vary widely, the same solution might not work for everyone.  But
here are some solutions that have worked for some people.

=== Pre-built TUI 2.6.0 ===

Download a copy of TUI pre-built for linux as of December 2017 at

http://www.apo.nmsu.edu/35m_operations/TUI-images/files/tui-centOS.tar.xz

Future TUI versions will be linked from the TUI-images web page so
be sure to check there also.

=== Install from the ground up ===


  - install miniconda2 using the usual installer
  - in miniconda2/bin do ./conda install python=2.7.12 to revert to python 2.7.12
  - create a file "pinned" in miniconda2/conda-meta with the line python ==2.7.12
  - in miniconda2/bin do "./conda install numpy=1.8.2" to install numpy 1.8.2
  - add line "numpy ==1.8.2" to "pinned"
  - in miniconda2/bin do "./conda install matplotlib"
  - in miniconda2/bin do "./conda install Pillow"
  - in miniconda2/bin do "./conda install astropy"
  - in miniconda2/bin do "./pip install pygame"
  - in miniconda2/bin do "./pip install RO==3.6.9”


=== Forcing package version at runtime ===