TY - CHAP A1 - Akimasa Suzuki A2 - Taketoshi Iyota A3 - Kazuhiro Watanabe ED1 - Auteliano Antunes dos Santos Júnior Y1 - 2012-03-07 PY - 2012 T1 - Real-Time Distance Measurement for Indoor Positioning System Using Spread Spectrum Ultrasonic Waves N2 - Ultrasonic waves are well-known for their broad range of applications. They can be employed in various fields of knowledge such as medicine, engineering, physics, biology, materials etc. A characteristic presented in all applications is the simplicity of the instrumentation involved, even knowing that the methods are mostly very complex, sometimes requiring analytical and numerical developments. This book presents a number of state-of-the-art applications of ultrasonic waves, developed by the main researchers in their scientific fields from all around the world. Phased array modelling, ultrasonic thrusters, positioning systems, tomography, projection, gas hydrate bearing sediments and Doppler Velocimetry are some of the topics discussed, which, together with materials characterization, mining, corrosion, and gas removal by ultrasonic techniques, form an exciting set of updated knowledge. Theoretical advances on ultrasonic waves analysis are presented in every chapter, especially in those about modelling the generation and propagation of waves, and the influence of Goldberg's number on approximation for finite amplitude acoustic waves. Readers will find this book ta valuable source of information where authors describe their works in a clear way, basing them on relevant bibliographic references and actual challenges of their field of study. BT - Ultrasonic Waves SP - Ch. 9 UR - https://doi.org/10.5772/30215 DO - 10.5772/30215 SN - PB - IntechOpen CY - Rijeka Y2 - 2019-12-07 ER -