The previous chapters laid down the foundation for the application of parameterestimation methods to dynamic systems. In this chapter several example applications are presented in which the methods of the first two chapters can be used to advantage with the class of dynamic systems discussed in the previous chapter. The problems and solutions are idealizations of “real-world” applications that are well documented in the literature cited. First, spacecraft attitude determination is introduced using photographs of stars made from one or more spacecraft-fixed cameras. Then, the position of a vehicle is determined using Global Positioning System (GPS) signals transmitted from orbiting spacecraft. Subsequent discussion involves the application of linear least-squares methods for simultaneous localization and mapping of an autonomous system based on identified landmarks. Next, spacecraft orbit determination from ground radar observations using a Gaussian Least Squares Differential Correction (GLSDC) is presented. Then, parameter estimation of an aircraft using various sensors is introduced. Finally, flexible structure modal realization using the Eigensystem Realization Algorithm (ERA) is studied. This chapter shows only the fundamental aspects of these applications; the emphasis here is upon the utility of the estimation methodology. However, the examples are presented in sufficient detail to serve as a foundation for each of the subject areas shown. The interested reader is encouraged to pursue these subjects in more depth by studying the many references cited in this chapter.