Reliable monitoring is the most critical aspect when considering safety in robotic operations. It involves real-time environment knowledge and hardware reliability, aspects that have been dealt at the TJO with the appropriate equipment.
Several sensors provide a reliable monitoring of the weather variables that are critical for the TJO operation safety. Redundancy is available for the majority of them (humidity, wind speed, rain detection, etc.), which guarantees safe decisions to preserve the integrity of the system.
- Previstorm. This sensor, manufactured by INGESCO, records the variations of the electrostatic field to predict thunderstorms.
- EM-Davis. It is a Davis Vantage Pro II weather station with four different nodes. One node is located outside the TJO building and it is equipped with sensors to measure wind, humidity, temperature and atmospheric pressure. The other three nodes provide temperature and humidity data. They are placed: at the TJO dome, at the ARES room and at the control room.
- EM-TFRM. It is a Vaisala weather station belonging to the Telescopi Fabra-ROA Montsec (TFRM) and located in the OAdM site.
- Rain detector. The rain detector is located close to the TJO dome. It is an IRSS88 model manufactured by Eigenbrodt.
- Boltwood Cloud sensor. The Boltwood Cloud Sensor II is located close to the TJO dome and provides differential information about the sky brightness temperature (and thus cloudiness).
- GPS. The Network Time Protocol is used, together with an on-site GPS (Garmin) antenna, for the redundant time-base determination.
The OAdM is powered by main frame power from the Endesa Company.
Several Uninterruptible Power Supply units (UPSs), using double-conversion online technology are installed at the TJO to supply power to the equipment that is very sensitive to power surges and requires electrical isolation: astronomical instrumentation, sensors, computers and dome. The use of several Power Distribution Units (PDUs) permit remote or automatic control of the power supplied to the different devices. The UPSs and PDUs distribute the energy to all devices and ensure electrical power for enough time in case of electric power cut.
The OAdM site is prone to electrical thunderstorms during Summer months. Protection against power surges is a must for the robustness of a robotic observatory such as the TJO.
The TJO facility is appropriately protected against lightning strikes and induced power surges using different kinds of filters (for Ethernet, RS232, etc). Filters for standard serial ports and network connectors are used, and opto-coupler elements (i.e., fiber optics transceivers) are implemented for the rest. Three filter classes are also used in the power distribution lines depending on the potential danger of the device to large overcurrent.
Internet communications is one more element to take into account when facing the safety of the observatory. A fiber-optics connection of 100 Mbps bandwidth is used for external communication. It connects the observatory with the Anella Científica (Scientific Ring), a high-speed communications network (2 Gbps bandwidth) managed by CSUC (Consorci de Serveis Universitaris de Catalunya), that connects universities and research centers in Catalonia. The network is connected to RedIRIS, the Spanish research network. Through RedIRIS, it reaches the most advanced international research networks. Continuous monitoring of the internet connection is done by CSUC and also by the control system of the observatory.