Quick Guide for Dummies - The novice 30m user

Howto observe ?

Getting started

A typical observing session: PaKo

Displays

Computer System

What are all the screens for ? Network topology or entering the unknown

mrt-lx1 is the name of the workstation to run the observations. This is the central machine, the observer is using for running PaKo. The online data processing software Odp is running on mrt-lx3. During observations it is continuously transferring IMBfits raw data from mrt-lx1 to mrt-lx3. The observer should use mrt-lx3 (or mrt-lx2) for offline data processing.

My machine is called mrt-lx18. Now what ? Software

Machines with larger numbers than 4, are small PCs used as terminals. Not much software is installed on these PCs and the user may want to quickly change to one of the main workstations described above, e.g. via ssh -X mrt-lx3.

Details like telescope and instruments

Data

Online data processing (Odp)

The Odp creates calibrated spectra online during the observations, stored in the so-called 30m files, and readable by class. In most cases, the observer works offline only with these files. However, in case of problems with the data, e.g. calibration issues, the observer needs to know to some extent what Odp is doing.

During observations, the backends take data and save them in streams in FITS format. These streams are merged with streams from other parts of the system, e.g. antenna mount drive, and also with messages, to be included in IMBFits raw data files. These are then combined by mira/odp to create calibrated spectra, usually on the antenna temperature scale TA*, and saved as 30m files. These in turn can then be read offline with class by the observer. Mira, class, greg are part of the GILDAS software package. Astronomical data therefore is created in several levels: level-1 are the streams, level-2 are the IMBfits files, level-3 are the 30m files. In case of calibration or other problems, it is possible to recalibrate data using MIRA, or even to recreate data from the streams.

Where are my data ?

• On the observers project account,

  • 30m data are found here: ~/observationData/mira. One file is created per backend and per day, e.g. FTSOdp20120105.30m

  • IMBfits raw data are found here: ~/observationData/imbfits. Their file name gives date, scan-number, backend, e.g. iram30m-fts-20120107s167-imb.fits.

What happens to my data ? Backup, Storage

How can I safe my data ? Use rsync, stupid !

Next steps: user dp

Howto work with spectra: CLASS

Howto work with data cubes: GREG

Whom to complain to ? Help needed

Don't be afraid of "silly" questions, please!

This page is maintained by CK. Any comments are welcome.