  The calculation of neutron reflectivity from raw time-of-flight data
including instrumental corrections as well as improved resolution calculation
is presented. The theoretical calculations are compared to experimental data
measured on the vertical sample plane reflectometer D17 and the horizontal
sample plane reflectometer FIGARO at the Institut Laue-Langevin, Grenoble,
France (ILL). This article comprises the mathematical body of the
time-of-flight reflectivity data reduction software COSMOS which is used on D17
and FIGARO.
