Dynamic modeling methodology

Abstract

Optical communication payloads require a stabilized Line Of Sight (LOS) to maximize signal. The LOS stability requirement is typically on the order of a few hundred nanoradians or less. A methodology of modeling the impacts of space vehicle disturbances and their propagation is presented that is used in the design, build, and test of the space vehicle and optical payload. The methodology permits the development of a successful system, without “overbuilding”. The three principle components of the methodology are; (1) Model Uncertainty Factor (MUF), (2) Sliding Window Analysis, and (3) Max-Median criterion. The MUF accounts for the inaccuracies in the dynamic model at various phases of the program. (e.g., Model only, after piece part test results are included in the model, after sub-assembly test, and after system test). The MUF also accounts for inaccuracies at higher frequencies of disturbance sources. The Sliding Window Analysis is used to account for the inaccuracies of exact mode frequency determination and the tunable disturbance sources. The Max-Median criterion sets the predicted performance value.