The Early Eighties: Development of In-Flight Transfer Alignment – Challenges and Methods

In the late seventies and early eighties, Rafael devolved a very advanced (at the time) transfer alignment algorithm. This required the development of an entire infrastructure for navigation work: strapdown navigation equations, navigation error model, Kalman filter implementation, system level error model, inertial measurement unit, real-time, floating-point computer, test design, implementation and analysis. This paper tells the story of this enterprise, from the preliminary studies to successful operational deployment, by pointing out the different phases and lessons learned.