LOIS - Lowell Observatory Instrumentation System: A modular control system for astronomical instrumentation

Abstract

The Lowell Observatory Instrumentation System (LOIS) is the control system for a series of new instruments at Lowell, including the SOFIA first light instrument, HOPI. Since these instruments will incorporate various detector systems and will be used with several telescopes, the concept of a loadable modular based design was developed. The fundamental idea is to view the telescope, camera, and other instrument components as separate, interchangeable entities. This interchangeable module system is based on the scripting language Tcl/Tk, using the extensibility of the language to change the hardware functionality of a command without changing the command. This provides a means to structure a set of static commands for different hardware systems. Using the same series of scripts and commands, HOPI and other instruments can maintain a library of observation programs to be utilized at different observatory sites. LOIS also provides an interface for control by a high-level external program to implement semiautonomous or robotic system operation. LOIS provides the flexibility to add new instrument, telescope, and camera interfaces without changing any other aspect of the main program, analysis, or image display functions, and provides a static and consistent interface for observers using the different camera systems and telescopes. It is already operating several CCD cameras at Lowell, another system at NASA Ames in support of the Kepler mission technology demonstration, and is being used to test the SOFIA mission control software system's instrument interface. Show more