GALEX Exposure Time Calculator
The GALEX Exposure Time Calculator (ETC) is used to simulate the GALEX instrument response for observations of different types of astronomical objects (stars, galaxies, and QSOs). There are two calculation methods that can be used with the ETC. The first method is to specify an exposure time and the ETC will return the predicted signal-to-noise ratio (SNR). The second method is to specify an SNR and the ETC will return the exposure time needed to obtain it.
The user must specify the flux from the object being observed, either using a flux density or magnitude. The ETC does not use the input position to compute the flux of the object being observed. The input position is only used to compute an estimated background at the position of the object being observed. Options that can be used to more fully describe the object being observed are available from the 'Advanced' interface.