The arcus operations simulator: a general tool for observation planning

Abstract

Arcus is a proposed pointed x-ray and UV Probe mission which will observe targets across the sky for extended periods of time. Total observation times for targets range from a few ks to 2 Ms, nearly all of which can be performed in a series of discontinuous exposures throughout the mission. The mission is also designed with a requirement to respond to Target of Opportunity (ToO) triggers within four hours. Arcus will not carry an all-sky monitor, and therefore new commands must be formulated on the ground and uploaded once a ToO trigger is received. We present the Arcus Operations Simulator (OpSim). This consists of the Observation Planning tool (ObsPlan), which will plan (and re-plan) the entire observing mission within minutes, accounting for relevant observatory restrictions, and the ToO tool (ToOT) which automatically rejects or approves ToO triggers, will rapidly notify Mission Operations (MOps), and will trigger ObsPlan to create and transmit an updated observation plan within 20 minutes. This software is modular and easily extensible and therefore may be of use for other pointed missions for creating their own observing plans.