LOFT (Large Observatory For X-ray Timing) is one of the four candidate missions currently
under assessment study for the M3 mission in ESAs Cosmic Vision program to be launched in
2024. LOFT will carry two instruments with prime sensitivity in the 2–30 keV range: a 10
m2 class large area detector (LAD) with a <1° collimated field of view
and a wide field monitor (WFM) instrument. The WFM is based on the coded mask principle,
and 5 camera units will provide coverage of more than 1/3 of the sky. The prime goal of
the WFM is to detect transient sources to be observed by the LAD. With its wide field of
view and good energy resolution of <500 eV, the WFM will be an excellent instrument
for detecting and studying GRBs and X-ray flashes. The WFM will be able to detect
~150 gamma ray bursts per year, and a burst alert system will enable the
distribution of ~100 GRB positions per year with a ~1 arcmin location
accuracy within 30 s of the burst.