The free-space communications community has only recently recognized the complexity of atmospheric channel
interactions, which are highly dependent on the turbulence profile, beam propagation geometry, and transceiver design.
The search for models that accurately describe link performance and overall availability is currently an active field of
research. This paper describes a method for defining link availability based on statistical channel models, which can be
derived from measured signal fluctuations during periods of stable atmospheric conditions. Measurements made during
an extended communication link experiment conducted during the summer of 2008 indicate that the intervals of channel
stability, which impact the length of link outages, can vary in duration from a few minutes to several hours.
This work was sponsored by the Department of Defense, RRCO DDR&E, under Air Force Contract FA8721-05-C-0002.
Opinions, interpretations, conclusions and recommendations are those of the authors and are not necessarily endorsed by
the United States Government.