Observation HOWTO

What is this document?

This is page is intended to be a quick instruction on how to do observations using the SCRT. This HOWTO assumes that you are familiar with how to log on to a linux system. If you are not, or if you are using Windows, please consult the Log-on HOWTO.


Before using the telescopes can be used of observations they must be unstowed manually at AlbaNova. Also the control box must be switched on. If nobody is doing this for you, and you have not done it before please check the instructions.

Logging on

Log on to scrt03.astro.su.se with your provided user name and password. If you are unfamiliar with this, please consult the Log-on HOWTO.

Starting qradio

The telescope control software is called qradio and is run by typing qradio east or qradio west. This text will only give a brief introduction to how to use qradio, for details please consult the qradio manual (not yet available). If everything is working you should see the following.

If the telescope has been unstowed and the control box switched on by clicking the offline button you should get control of the telescope, and the butten should turn green and the text changes to online.

FITS directory

The directory where the data files will be stored can be specified by going to the File and choose Fits dir.


Specifying the source

To move the telescope go to the Edit menu and choose Source, which will open a dialog window which is more or less self explanatory. You can specify the name of the source, and select in which coordinate system you wish to specify the target. The coordinates are given as:


If you wish to study the Milky Way, the equatorial to galactic coordinate conversion diagram below, could be of use. This is also available as PostScript and PDF for high quality printing.

The shaded grey region shows the area that is out of range for the telescope.

Once the position has been entered and the dialog window is closed the commanded position in the choosen coordinate system will bi showed at the bottom of the main window under the label position. The very same position expressed in the horizon system is shown under the label cmd, and act shows the current position of the telescope.

Moving the telescope

Make sure that the elevation in cmd is greater than 10 degrees, before pushing the button parked. This will make the telescope start slewing towards the commanded position and the movement can be followed in the act field. When the target is reached the text in the parked button will change to tracking, and the movement across the sky of the object will be followed by the telescope. If you wish to increase the hands-on feeling, you may watch the movement of the telescope using our Live WebCam.


To take a radio spectra, first choose mode switched, and change switching to freq switch.

The signal and reference gains should also be edited. A good start is to put both to something like 8.5. The best way is then to take a test integration and then change the gain iteratively in order to get a zero lag close to 2.9. The value of the gain will change depending on the altitude of the object, the time of the day, your shoe size, and so on.

The actual integration is started by pressing the idle button, and the result is displayed in the main window, and stored in two files the specified Fits dir (default is the directory where you started qradio). Two files are saved for each integration, one for the signal and one for the reference. Your screen should look like this

Finishing up

When all observations are complete, the telescope should be put in its parking position which is specified on the index page.

Finally the telescope should be stowed. If nobody is doing this for you, and you have not done it before please check the instructions.

Logging off

Log off from scrt03.astro.su.se. If you do not know how, consult the Log-on HOWTO.