8.1.5 Imaging Sensitivities

The sensitivity of the FPI+ in its different Sloan filters was measured in-flight as part of the camera upgrade verification. The selected star field had targets with a wide range in V mag brightness (11.1 < V mag < 16.7). The full-frame images were acquired with an exposure time of one second without pixel binning. The SNR values in Figure 3 are the result of aperture photometry with an exponential fit in the logarithmic plot. Displayed are the results of the OPEN configuration and the Sloan filters g’, r’, i’, and z’. The plot for the “daylight” filter is a calculation based on a filter transmission measurement done in the lab. The Sloan u’ filter is not displayed in this plot because it requires much brighter stars due to the low system throughput at the corresponding wavelengths. To achieve significant SNR values in the Sloan u’ filter, stars should be brighter than V mag=6.5.

Signal to Noise Ratio (SNR) for point sources imaged with FPI+

Figure 8-3: Signal to Noise Ratio (SNR) for point sources imaged with FPI+ at tEXP = 1 sec. Displayed is the OPEN broadband configuration as well as the spectral Sloan filters g’, r’, i', and z’.