Implications of the Sample Rate on Large Space Telescopes

Abstract

The frequency at which a large space telescope's (e.g. NGST's) detector chips are read, or the sample rate, is tightly coupled to many hardware and operational aspects of the telescope's instrument and data handling elements. In this paper we discuss many of the drivers and important implications fo the sample rate: the data rate to the ground; onboard computer storage, bandwidth, and speed; the number of A->D chips, and therefore the overall size and power requirements of the analog electronics; cryocabling requirements; and detector noise and power. We discuss and parametrize these and other elements related to sample rate. Finally, we discuss the implications of sample rate in the context of achieving the most important science goals under the constraint of fixed cost.