Development of long-term stability models for ring laser gyros

Time series analysis (TSA) techniques are applied to the modeling of ring laser gyro (RLG) long-term stability data. Results are presented for two sets of bias stability data: one for an RLG which exhibited drift rate performance of roughly 0.03 degree/hour, and the other for an RLG in the 0.004 degree/hour area. The approach taken to time series analysis is described; this includes the special derivations necessary to transform the models into a form in which they can be readily input into a covariance analysis of an inertial navigation/guidance system. The need for long-term stability models and the steps required to obtain these models, within some confidence level, are discussed.