The Usability of the ASCOM in Remote Control of a Site-Survey Telescope

Site surveys for potential astronomical observing stations are generally in rather remote places with very harsh living conditions. The remote telescope-control technology can greatly reduce the requirements of on-site operations and improve the quality of observation data, so it is important for the astronomical site testing. Based on the ASCOM standard, we have designed and implemented a prototype remote telescope control system. In this paper, we introduce the details of the system design, including those about the service end and client end. On the service end there are four steps, i.e. selecting a device, starting listening, establishing client connection, and responding to the client request. On the client end, there are also four steps, which are connecting to the server, setting up the timer, receiving information, and sending commands. The connection between the client and the server has two types, command line and GUI. All commands can be split into two parts, the command name and the command parameters. After the connection is built, RA, DEC, Az, and Alt are displayed in real time on the client end, while the telescope and CCD can be controlled on the GUI. This includes inputting a new diretcion (RA and DEC) to point the telescope, and clicking mouse buttons to track targets, park/unpark the telescope, enter CCD exposure time, and set image directory/file name. We tested the prototype on a narrow-band dial-up network and controlled a real remote telescope successfully. The result shows that it not only is an effective system to control a remote telescope and other devices, but also has the advantages of short and easy deployment. It also meets the requirements of the telescope remote control of a site survey.