  Timing of high-count rate sources with the NuSTAR Small Explorer Mission
requires specialized analysis techniques. NuSTAR was primarily designed for
spectroscopic observations of sources with relatively low count-rates rather
than for timing analysis of bright objects. The instrumental dead time per
event is relatively long (~2.5 msec), and varies by a few percent
event-to-event. The most obvious effect is a distortion of the white noise
level in the power density spectrum (PDS) that cannot be modeled easily with
the standard techniques due to the variable nature of the dead time. In this
paper, we show that it is possible to exploit the presence of two completely
independent focal planes and use the cross power density spectrum to obtain a
good proxy of the white noise-subtracted PDS. Thereafter, one can use a Monte
Carlo approach to estimate the remaining effects of dead time, namely a
frequency-dependent modulation of the variance and a frequency-independent drop
of the sensitivity to variability. In this way, most of the standard timing
analysis can be performed, albeit with a sacrifice in signal to noise relative
to what would be achieved using more standard techniques. We apply this
technique to NuSTAR observations of the black hole binaries GX 339-4, Cyg X-1
and GRS 1915+105.
