2.2 Preliminaries

Designing observations for Spitzer is, in many ways, a familiar process; the necessary steps to follow are common to creating any observing proposal. Assuming you have settled on the science goals of your proposal, the preparatory work includes, at minimum:

1. Select targets for observation (including a duplication check against the Reserved Observations Catalog database using Leopard to verify that desired targets have not already been observed, or approved for observations, with Spitzer).

2. Determine IR background at the target locations.

3. Estimate instrument sensitivity.

4. Calculate the exposure time required to reach the desired signal-to-noise (S/N) ratio.

5. Design the observations.

While the focus of this Cookbook is to provide detailed examples of the last step, in the next section we will provide some background information to make some of the preliminary work easier to accomplish.