To model interferometric data, has to compute model visibilities taking into account the measurement process and all its limitations.

The integration time, *scans.int_time*, is defined as the length of
time over which the data were averaged to yield the given data point.
For large sources, e.g. wide binaries, long integration times can
significantly lower the averaged fringe contrasts. Taking the system
variable !int_time to specify an upper limit for the integration time
in seconds which will not require integrating the model visibilities,
will compare the actual integration times to this limit and
determine the maximum number of computations required to cover the largest
integration interval. The step size for each observation will be adjusted
according to the actual integration time of the particular observation,
given the number of computations.