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New Control System (NCS) in Operation at the 30-Meter Telescope

In November 2005 the control system for the 30-meter telescope was changed to new hardware and software, built on the VME and Linux standards. This step was the result of several years of development by an NCS core team with eight members at IRAM Granada and Grenoble, as well as related work on data processing software.

For early observations, only a limited set of features was supported. More have been added in the meantime or will be in the near future. Since December 2005, observations have been possible with the single-pixel heterodyne receivers and the bolometer. The 4MHz and 1MHz filterbanks and VESPA (autocorrelator) are supported as well as the continuum backends, including ABBA for the bolometer.

All four standard ``switching modes'' can be used, i.e. Total Power, Beam, Wobbler, and Frequency Switching. Supported observing modes are Calibration for heterodyne receivers, Pointing, Focus, Tip (for the bolometer), Track (single position with frequency switching), ON-OFF, and On-The-Fly (OTF) maps.

Only observations of planets and sources in the Equatorial J2000 system are well tested up to now, with offsets in the radio projection, in true-angle horizontal coordinates, and in the Nasmyth system, i.e., for receiver pixels that are offset from the main axis.

The observer interacts with the NCS through a new command-line interface nicknamed ``paKo'' using the usual SIC interpreter. Most paKo commands are similar to those in the old control system, but already prepared for additional flexibility. The full paKo program can run detached from the rest of the NCS, e.g. for preparing and testing source and line catalogs and scripts for the setup of hardware and observing modes.

Most data are acquired continuously in independent data streams, which are then automatically combined into raw data files in FITS format. For heterodyne and spectroscopy data, new software (MIRA) can read data from these FITS files and analyze and plot calibration, pointing, and focus measurements. MIRA also applies calibration results to the data to plot calibrated spectra and write them to files in CLASS format for further processing. Up to now MIRA has been used manually, but for standard observations it will be automated in the near future. For bolometer data the MOPSIC software plays a similar role.

Up-to-date news and notes about the NCS are available to visitors on a set of dedicated web pages at the observatory.

Support for HERA and WILMA, more observing modes, and other coordinate systems will be added in early 2006, as well completely new options and observing modes.

Information about the NCS, including the user manual, is available at:


next up previous
Next: Scientific Results in Press Up: IRAM Newsletter 65 (February 2006) Previous: Call for Observing Proposals