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7.5 Format-Dependent Sensitivity

The sensitivity of the FOC depends on the format being used. The overall (OTA + COSTAR + FOC) central absolute quantum efficiency Q(

) in counts photon-1 (DQE), plotted in Figure 4.3 and tabulated as a function of wavelength in Table 11 of the FOC Instrument Handbook (version 7.0), refers to the 512 x 512 format. Because the DQE is a function of detector format whose cause is unknown (see FOC ISR 075), we give in Table 7.3 the sensitivities of the other formats, relative to the 512 x 512 format. Typical uncertainties in these numbers are approximately 5%.

**Format-Dependent Sensitivity Ratios**
Camera	Format (FxL)	Relative Sensitivity
f/96	512z x 1024	1.25
	512z x 512	1.45
	512 x 512	1.00
	256x256	1.20
	128x128	1.23
f/48	512zx1024	1.44
	256zx1024	1.28
	512x1024	1.02
	512x512	1.00
	256x256	0.85

The pre-COSTAR overall (OTA + FOC) central absolute quantum efficiency Q() in counts photon-1 (DQE) with no filters in the beam is plotted and tabulated as a function of wavelength in Figure 28 and Table 12 of the FOC Instrument Handbook, version 3.0, for the FOC imaging and spectrographic configurations. The data represent the product of in-orbit measurements for the f/96 camera and ground-based measurements of the f/48 absolute quantum efficiency, reflectance measurements of the OTA primary and secondary mirrors witness samples and an arbitrary dust covering factor of 10%. Pre-COSTAR data are not automatically corrected for format-dependent sensitivity effects.

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7.5 Format-Dependent Sensitivity

Camera

Format

(FxL)

Relative Sensitivity

Relative
Sensitivity