The ALIS control centre

The ALIS control centre (CC), is located in the optical laboratory of IRF in Kiruna (Figure 2.6).

Figure 2.6: The ALIS control centre at the optical laboratory as it looked around 1993. To the left are workstations and the station computer for the Kiruna station. The station overview map and console for the HP-755 workstation are seen in the center-right part of the photo. The two racks to the right contains monitors for the low-light TV-cameras, video recorders and timing systems.

In the CC there are computers for controlling ALIS, communication equipment (e.g. modem pools for dial up connections) and workstations for running ALIS (Figure 2.7).

Figure 2.7: Block-diagram of the ALIS control centre (CC) at the optical laboratory, IRF Kiruna. The control centre consists of the gateway for dial-up access to the remote stations (octopus.irf.se) and its modem-pool. ALIS is controlled from the main computer (www.alis.irf.se) which also contains the web-server for ALIS. GOSSIP is a status display showing status and alarm information from the stations on a map [Tornéus, 1992]. The operations centre (OC) was initially located at the CC, but was later moved to Knutstorp (see text). It consists of a PC workstation and two X-terminals. Supporting optical instruments, for example low-light TV cameras, are also available at the OC. ALIS station 1 is located at the same site as the OC and they are both connected to the IRF LAN over a microwave link.

In 1999, as ALIS station (1) Kiruna was moved (Section 2.1.2) a secondary point for controlling ALIS, an Operations Centre (OC) was established at the same place as station 1 (Figure 2.8). This was done in order to minimise disturbances from

Figure 2.8: The ALIS operations centre that was established at Knutstorp (close to the EISCAT-site in Kiruna) in 1999. Two low-light TV-cameras (one with all-sky, and one with $\approx 40^{\circ}$ field-of-view) are used to give the operator a real-time display of the sky. These images are displayed on the monitors in the upper left part of the photograph. Below are two video tape recorders. The six ALIS stations are monitored and controlled from the computer terminals below, and some quick-look images from ALIS are seen on the screens.

construction work at the CC. It is desirable to be able to run supporting low-light instruments and to make visual observations when running ALIS. While most ALIS operations have been undertaken from the CC or OC, it is worth noting that ALIS can be controlled from almost any computer with a suitable Internet connection. During unattended operations, a pager call can be used to alert the operator on duty of abnormal conditions. The pager is also used for alarm messages (for example fire, trespass, power-failures, etc.) from the housekeeping units at the stations during non-measuring periods.

In the beginning, there were many technical requirements on the CC [for example Steen, 1989; Steen et al., 1990]. As ALIS evolved the requirements on the CC were relaxed, and if, all stations obtain high-speed Internet connections, it will be completely superfluous, at least from a technical point of view. On the other hand, experience has shown that a dedicated centre for running ALIS campaigns, where scientists and staff can gather and run the observations, review results as well as solve problems, yields far better results as compared to if one single person runs ALIS from home or an office. Therefore it is probably important to have a dedicated operations centre for ALIS, despite the fact that ALIS can be run from almost anywhere.