Preparing observations

Observations with the Effelsberg dish are easy and straightforward. However you must well prepare the observations, be strict with typing the operational command and know what you are doing. All the settings of the telescope receivers, specifications of the observing area on the sky etc. can be done with a few files. The files should be prepared on the VAX computer standing on the right of the operating console.

What you need

1.      The position of the target (e.g. IC2574) in B1950 coordinates

2.      The size (in arcmin) of the area on the sky you want to map. Single map, so called scan, consist of several subscans which correspond to single telescope azimuthal scanning of the sky area. At 6cm the standard step between subscans (e.g. in elevation) is 1’. For example the scan 45 x 36 will be done in 37 subscans with 1’ separation.

3.      The name of your amplitude calibrator. Take 3C286 if visible above the horizon or 3C138 (they are almost on the opposite sides of the sky so always one of them is visible).

4.      The name of your pointing calibrator. Find a nearby strong radio source close to your target in the so called “Helmut" catalog (Kuhr). It is the green book in the operating room in Effelsberg. The important is the “SNAME" of the source, because it is recognized by the operating program. An example of SNAME: 3C231.0. You use this name during observations.

Needed files:

obsein.pro                             - files with aliases for setting the receiver and the mod

                                                 of observations - already prepared by R. Beck

6back.obs                             - backend settings - already prepared

6point.obs                             - settings for cross-scan observations (for pointing) of

- the amplitude or pointing calibrator -prepared

6caldh.obs                            - parameters for making a small map of the amplitude

  calibrator - prepared

IC2574.obs                           - parameters for a map of your target (IC2574 in this

  case) - you must prepare it

On the VAX machine eff100 prepare the observing file (ic2574.obs):

login: observer

password:                                                    ask the operator

set def  [observer.kont.6]                             change directory to 6cm

dir   (or ls)                                                    list the directory (ls also works)

dir *.obs                                                      list files

type obsein.pro                                            list the file obsein.pro

print obsein.pro                                            print obsein.pro

copy n6822.log  ic2574.log                        copy file

purge ic2574.obs                                        delete file

edit ic2574.log                                             start editing ic2574.obs

            use arrows for movements

            bckspace

            ‘           - delete

            PF4 -delete line

            ctr-Z  and exit  -  to exit editing with saving