Characterization of silver and aluminum custom mirror coatings for the MRO interferometric telescopes

We report on the design, application, and testing of custom protected silver and aluminum coatings for use on the Magdalena Ridge Observatory Interferometers (MROI) unit telescopes. The coatings were designed by Optical Surface Technologies (OST), and tested under normal observational conditions on Magdalena Ridge. Mirror coating samples fabricated by OST were given to MRO, and then placed in an insulated automated enclosure at the observatory site. Within the enclosure, environmental conditions such as temperature and humidity were continuously monitored. The automated enclosure was instructed to open during the night dependent upon weather conditions matching those that would occur under normal operations of the interferometer. This paper tracks the affect of the Magdalena Ridge environment on the performance of the coatings, specifically with regards to reflectivity.