6.1.4 Imaging Sensitivities

The Minimum Detectable Continuum Flux (MDCF; 80% enclosed energy) in μJy needed to get S/N = 4 in 900 seconds has been estimated for each filter for an altitude of 41,000 feet (7.3 μm of precipitable water vapor) from a model of the instrument and the atmosphere. The values are presented in Table 6-1 above and are plotted in Figure 6-4. The horizontal bars on the data in the figure indicate the effective bandpass at each wavelength. At the shorter wavelengths the bandpass is sometimes narrower than the symbol size.

Atmospheric transmission affects sensitivity, particularly at wavelengths > 4 μm, depending on the water vapor overburden. In addition to the theoretical sensitivity values for FLITECAM we have included the as-measured imaging sensitivities in the FLIPO (combined HIPO+FLITECAM) mode. Until the instrument has been more accurately characterized at these longer wavelengths, the L and M band filters will be offered on a shared risk basis.


FLITECAM imaging sensitivity

Figure 6-4: Theoretical FLITECAM imaging sensitivities for a continuum point source at the effective wavelengths of the FLITECAM filters listed above (red boxes). Yellow boxes indicate the imaging sensitivities for the FLIPO configuration (i.e. FLITECAM co-mounted with HIPO). The values reported are for a S/N of 4 in 900 seconds at water vapor overburdens of 7 μm. The horizontal bars correspond to the photometric band pass.