  The probability that an existing planetary transit is detectable in one's
data is sensitively dependent upon the window function of the observations. We
quantitatively characterize and provide visualizations of the dependence of
this probability as a function of orbital period upon several observing
strategy and astrophysical parameters, such as length of observing run,
observing cadence, length of night, transit duration and depth, and the minimum
number of sampled transits. The ability to detect a transit is directly related
to the intrinsic noise of the observations. In our simulations of observational
window functions, we explicitly address non-correlated (gaussian or white)
noise and correlated (red) noise and discuss how these two noise components
affect transit detectability in fundamentally different manners, especially for
long periods and/or small transit depths. We furthermore discuss the
consequence of competing effects on transit detectability, elaborate on
measures of observing strategies, and examine the projected efficiency of
different transit survey scenarios with respect to certain regions of parameter
space.
