Micro-Electro-Mechanical-Systems (MEMS) sensors constitute perhaps the most exciting technology of our age. The present effort incorporates all the information needed by scientists and engineers who work on research projects and/or product systems, which apply to air pressure acquisition and to its rearrangement into altitude data. Some of the potential implementations of this method (regularly referred to as barometric altimetry) include, but are not limited to, Position Location Application, Navigation Systems, Clinical Monitoring Applications, and Aircraft Instrumentation. This book holds the key to such applications, providing readers with the theoretical basis as well as the practical perspective of the subject matter. At first, the reader is introduced to the background theory, methods, and applications of barometric altimetry. Thereafter, the book incorporates the development of wireless barometers and a (real-time monitoring) wireless sensor network system for scheduling low-cost experimental observations. Finally, a deepened understanding to the analysis procedure of pressure measurements (using Matlab script code) is performed. Some accompanying material can be found at http://bit.ly/mems-files.