A robotic telescope is an astronomical telescope and detector system that makes observations without the intervention of a human. In astronomical disciplines, a telescope qualifies as robotic if it makes those observations without being operated by a human, even if a human has to initiate the observations at the beginning of the night, or end them in the morning.
A robotic telescope is distinct from a remote telescope, though an instrument can be both robotic and remote. Robotic telescopes are complex systems that typically incorporate a number of subsystems. These subsystems include devices that provide telescope pointing capability, operation of the detector (typically a CCD camera), control of the dome or telescope enclosure, control over the telescope's focuser, detection of weather conditions, and other capabilities.
Frequently these varying subsystems are presided over by a master control system, which is almost always a software component. In Ikarus Observatory, Ekos Scheduler serves as the master control system. One observations are scheduled, the Ekos Scheduler can be started in completely autonomus mode.
Robotic telescopes operate under closed loop or open loop principles. In an open loop system, a robotic telescope system points itself and collects its data without inspecting the results of its operations to ensure it is operating properly. An open loop telescope is sometimes said to be operating on faith, in that if something goes wrong, there is no way for the control system to detect it and compensate. A closed loop system has the capability to evaluate its operations through redundant inputs to detect errors. A common such input would be position encoders on the telescope's axes of motion, or the capability of evaluating the system's images to ensure it was pointed at the correct field of view when they were exposed. Most robotic telescopes are small telescopes. While large observatory instruments may be highly automated, few are operated without attendants.