Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.astro.louisville.edu/software/xmtel/xmtel-7.1/DOCUMENTATION Дата изменения: Thu Jun 18 19:34:27 2015 Дата индексирования: Sun Apr 10 02:18:17 2016 Кодировка: Поисковые слова: ngc 4303

XmTel
-----

XmTel is a Motif-based telescope control program developed by John Kielkopf
(kielkopf@louisville.edu) to operate a telescope connected to a Linux computer
system. The most recent version should be available from

http://www.astro.louisville.edu/software

XmTel is offered under the MIT License without warranty of any kind. See the
files LICENSE and COPYRIGHT for the details. Because unattended operation of a
telescope could inadvertently damage it, we urge you to be very careful when you
use this software. Exercise the software thoroughly before trying to use it in
the dark, or from the warm comfort of your computer console when the telescope
cannot be directly observed.

The default installation assume /dev/ttyS0 serial port telescopes. In the
present version, you have to change this at compilation time for another port.
See INSTALL for more information about insuring the permissions for the serial
device driver are set properly.

If your telescope is connected to the computer you are using as a console,
simply start xmtel and xephem on the command line

xmtel &
xephem &

You may also a standalone daemon rather than a graphical user interface (GUI)
by running xmtel with the command line

xmtel -d &

which may be convenient for remote operations or for automation through scripts.
If you are running remotely see REMOTE for more information on how to use xpa
for command line operation.


When xmtel is launched you will see a control panel with the following
functions:

"File" offers the option of new Log and Queue files, and the usual Exit.

"Edit" enables editing Log and Queue files.

"Pointing" has radio button selections to enable pointing corrections.

"Reference" allows you to set the offsets based on the present Target.

"Telescope" is for focus, image rotation, and thermal control if available.

*Guide *Center *Find *Slew radio buttons select the speed for the NSEW
buttons. Slewing operations will always be at slew speed.

NSEW buttons move the telescope as long as the button is depressed. The
coordinate display updates when the button is released.

Telescope and Target RA and Dec display the coordinates of the telescope and
the most recently selected target. A click on the Epoch entry will toggle it
from "Now" to "2000". This is for display purposes only and does not affect the
actual pointing. You may enter a target from the keyboard by clicking on the
entries for RA or Dec for the Target field.

Target entries may be more conveniently handled from the GUI by using XEphem.
Right click on the object of interest, select Telescope GoTo, and the target
field will be filled in for you. For planets, comets and asteroids
click on the closest star/

Target entries may be filled in from a queue file. If a new queue is selected
the names of its entries will appear in the scrollable display panel at the
center of XmTel. Just click on one and its coordinate entry will be transferred
to the Target field. A convenient way to make a queue list is to copy the
information from the catalog entry for XEphem, using XEphem's format. See note
about orbital objects above.


Below the queue field there are eight buttons that control telescope functions:

Save puts the contents of the telescopes current location in a log file and
pushes into a ring memory buffer. You can use this to return to a particular
position.

Recall will take values from the memory buffer and put them in the target field.

Meridian will load the target field with the coordinates of the meridian at the
present declination.

Zenith will load the target field with the coordinates of the zenith.

Pole will load the target field with the coordinates of the pole at the present
hour angle.

Track will start tracking if, for some reason, it has been disabled.

Stop will stop sidereal rate tracking. It may also stop a slew in progress, but
this is not guaranteed. (See the main README for cautions.) A master stop or
power switch near the keyboard, indepenent of xmtel, is recommended
just in case.

A message field appears at the bottom of the control panel.


About Epoch
-----------

XmTel assumes that the telescope is set to "Epoch of Date", which means that it
is using ideal celestial coordinates precisely aligned today. The correction
routines make adjustments for refraction, flexure, and mechanical misalignments
of the mounting telescope. The protocols which are provided here for use with
XmTel operate on this principle. The LX200 and NexStar telescope operating
systems use an approximate Epoch of Date. The differences between the two
systems should be far less than the pointing error after corrections are
applied.

Coordinates which are displayed on the console also may be in an Epoch 2000.
XmTel assumes that target coordinates entered from the keyboard are in the
Epoch that the telescope coordinates are currently displayed in.

Coordinates which are transferred from XEphem may be in another Epoch, depending
on the catalog selected and the internal operation of XEphem. XmTel precesses
catalog entries to epoch of date, and allows for proper motion if known.


About Time
----------

XmTel requires an accurate system time. It is advisable to either set the
system clock using the NIST website, or to use NTP services to maintain an
accurate system clock. Without an accurate time, XmTel will have errors in RA
of the order of the error in system time. These errors may be cancelled by
using an offset correction, but the best solution is to have the right time to
minimize the need for offsets.