  Muon ring images observed with Imaging Atmospheric Cherenkov Telescopes
(IACTs) provide a powerful means to calibrate the optical throughput of IACTs
and monitor their optical point spread function. We investigate whether muons
ring images can be used as the primary optical throughput calibration method
for the telescopes of the future Cherenkov Telescope Array (CTA) and find
several additional systematic effects in comparison to previous works. To
ensure that the method achieves the accuracy required by CTA, these systematic
effects need to be taken into account and minor modifications to the hardware
and analysis are necessary. We derive analytic estimates for the expected muon
data rates to be used for optical throughput calibration, monitoring of the
optical point spread function, with achievable statistical and systematic
uncertainties, and explore the potential of muon ring images as a secondary
method of camera pixel flat-fielding.
