Simulated modulation factors as a function of energy for three cases; diamonds represent the hypothetical case of an on‐axis GRB (with the same spectra of GRB 041219) with 19 detectors on, using the actual directions from simulations (case b), filled circles and crosses represent the known position of GRB 041219a with 17 detectors, with cases b, and c, respectively (see text for more explanation on each case). All three cases are pixellated.