The plot below shows comparison between effective areas of different detector's with respect to their energy coverage. Daksha's LE detectors are shown in blue, ME detectors in purple and HE detectors in green. Effective areas of Swift-BAT, Fermi-GBM and Fermi/BGO are plotted for comparison.
The effective area, as a function of position, in satellite coordinates is shown below. The satellite X axis is the centre of the figure, and the Z axis is at the top. In this orientation, the Sun will always be at the bottom of the figure. About 29% of the sky will be occulted by the Earth at any given instant.
Daksha all-sky effective area over the entire
The workhorse for Daksha are the ME detectors. Each surface has this package with 20 detectors, adding up to a total collecting area of 304 cm2 on each surface. Considering projection effects over the entire visible sky, the median effective area for Daksha ME detectors is ~1300 cm2 at 100 keV over the non Earth-occulted sky. This is signicantly higher than the 126 cm2 on-axis effective area for individual NaI modules on Fermi GBM (Meegan et al. 2009), which has a similar orbit and also covers the entire non-occulted sky.
Our effective area is comparable to the effective area of the Burst Alert Telescope (BAT) on the Neil Gehrels Swift Observatory (Gehrels et al. 2004; Barthelmy et al. 2005), though BAT can observe only about 11% of the sky as opposed to 71% for Daksha. The effective area gradually tapers off above 100 keV.