3 THE OBSERVING PROCESS

After the submission of project information is complete, an APEX staff astronomer is assigned to each submitted project as Local Contact. This person is responsible for all matters regarding this project.

1 Project accounts

For each APEX project for which project information has been successfully submitted, a project account is created. The creation of a user account in the APEX computer network is a sensible issue in terms of security, thus the account has to be created manually by the APEX staff. With the creation of the project account, a few other tasks are performed automatically, among them:

• All files generated during project submission which were not handled by associated programs (see Section 2.4) are copied into the project account home directory.
• Directories are created on the data reduction computer and the archive computer to store the MBFITS raw data files and (in case of heterodyne projects) the calibrated CLASS format spectra.

Before an observation session is started, the APEX staff performs another task manually: the verification (and adjustment, if necessary) of the previously created and copied setup and observe macros. With this step, the project is ready to be observed.

2 Servers and clients

From the observers point of view, the APEX Control System (APECS) is composed of a server level and a client level. Actually, APECS contains many more aspects, which are of minor interest here[2]. The servers contain the main functionality of APECS, they run on three computers which are located in the telescope itself or the control building nearby. The clients can run on any computer within the APEX network; they provide the main interface for the observer and run under the project account. One of them, the APECS command line interface (APECS CLI), provides a scripting language to set up the system and run the observations. The macros created by the project submission system are executed under this scripting language.