IEEE-AES is disseminating information to people in the profession, providing a foundation of understanding to make up for attrition as experts retire and become unavalible. As part of this IEEE program, this presentation focuses on two pervasive areas of navigation - inertial (Part ONE) and satellite-based (Part TWO). For brevity the presentation emphasizes main points, with the understanding that available references show adjustments to provide all needed refinements. The same holds true for details. For example, I show flight test results with updates I made from GPS data using Kalman filters -- but an hour and a half isn't enough time to cover Kalman filtering. Those unfamiliar with Kalman filters may concentrate on just the way those fixes are formed, irrespective of Kalman's theoretical derivation with all its mathematical ramifications. Although the main emphasis is on fundamentals, I manage to include some advanced concepts. For example, the flight results just mentioned were achieved by using 1-second sequential changes in GPS carrier phase for dead reckinong only. Immediately that eliminated three fundamental major vulnerabilities present in conventional usage of carrier phase. In addition I draw attention to motion-sensitive errors of inertial instruments, which don't receive enough emphasis in so much of our industry today. I also describe unaided operation, that is, "free-inertial" navigation -- without correction via GPS or other measurements. For those who want to go further into inertial and/or satellite navigation,there are two books having notation and perspective consistent with this presentation, One is a basic book I wrote in 1976 -- before GPS came of age -- plus a recent (2007) book heavily emphasizing GPS. For more information, visit my web site at JamesLFarrell.com.