Instructions for using Xephem

Updated 061006 / alien

• Log yourself to antimatter (ssh)
• Create yourself a directory called XEphem

• Start xephem
• The window that opens is the so called main window. First choose the right location (if Metsähovi isn't default yet): Click button Chicago, Illinois and find Metsahovi from the list.
• Choose from the main window "Looping" (down right), click the button "Now".
• Click "update".
  (Now the program is looping in real time and the LST -clock is working etc.)
• Go to "View" -menu and choose "Sky View"
  (Now the window that shows all stars etc. appears)
• Go to the "Data" -menu (main window) and choose "Load/Delete local files".
• Choose "Control" -menu from that window and then "Delete" and "Yes..delete all". Now all the objects from your Sky view disappeared.
• Then choose from that window button "Shared Dir" and from the above box "gix_new.edb". Then choose the button "Load".

Now the Sky View shows all objects from our sourcelist that can be currently seen.

• Go to Sky View window and choose "Control" -menu and there "Options..."
• Choose "Grid control": "Alt-Az" and button "grid".

Now you can see the elevation and azimuth -lines

• Then close the Options window (if you don't want to try something else, for ex. remove the lines from constellations)

Now you have made all the important settings and can see our sourcelist in the Sky View window. The big yellow dots are calibration sources DR21, 3C84 and 3C274. The big red dots are priority 1 sources, which mean that they must be observed everytime possible and usually many times a day. The middle-sized yellow dots are standard and pointing sources, the middle-sized red dots are GPS and CSS sources. The small red dots are monitoring sources from lists M1 and M2, the small blue dots are the BLO sources and the small yellow sources are everything else. Then there are the sun and the planets.

When you click the right mouse button above a dot, you can see the information of the source. For example the name and the coordinates and its elevation etc. The type of the source is wrong (star), because other classes are harder to define.

How can the program help with the observations:

• You can see where the sources are and then observe them at their best position. For example the altitude of the source is important. Usually you don't want to observe sources below 20 degrees unless they are very southern sources and are culminating.
• It is easier to choose sources from same direction to put into an autofile.
• You can check which sources can be seen at a certain time.

Obs: South is az= 180, and the zero is at north, so there is no negative azimuth. You can also change the azimuth position of the map with the scrollbar, so there can be confusions. You can also use the elevation scrollbar, for example to change the horizon to 20 degrees ( to make sure you don't observe sources below 20 degrees).

When you end the observations, you can save your settings so that Metsahovi is the default location.

Last modified: Mon Sep 6 11:25:35 EEST 2004