  A common target acquisition strategy with the Faint Object Spectrograph (FOS)
on board the Hubble Space Telescope (HST) is to use a sequence of so-called
ACQ/PEAK stages. Standard sequences and exposure times are given in the FOS
Instrument Handbook (Keyes et al.~1995). The success of a given strategy is
difficult to predict a priori for targets other than point sources. This paper
describes software that simulates ACQ/PEAK acquisitions in a Monte-Carlo
manner, for a variety of targets. The software is available from the FOS
Instrument Scientists or from the author. It allows a proper quantitative
assessment to be made of whether an acquisition will succeed, what exposure
times should be used, and how the efficiency can be optimized.

Astrophysics