6.2.3 Estimation of Exposure Times

The exposure times for FLITECAM imaging observations should be estimated using the on-line exposure time calculator, SITE. SITE can be used to calculate the signal-to-noise ratio (S/N) for a given ''total integration time'', or to calculate the total integration time required to achieve a specified S/N. The format of the S/N values output by SITE depends on the source type. For Point Sources, the reported S/N is per resolution element, but for Extended Sources, it is the S/N per pixel. The total integration time used by SITE corresponds to the time for a single chop/nod pair, without overheads.

The exposure times for FLITECAM grism mode spectroscopic observations should be estimated using the on-line exposure time calculator. This calculator can be used to calculate the signal-to-noise ratio (S/N) for a given ''total integration time'', to calculate the total integration time required to achieve a specified S/N, or to estimate the limiting flux for a desired S/N. For both imaging and spectroscopy modes, the estimated total integration time from the respective calculators should be used as the time for an observation in the SOFIA Proposal Tool (SPT; further details in Section 11.1). Overheads should not be included, as SPT calculates them independently.

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