**Applications**

20 Will-be-set-by-IN-TECH

64 Magnetic Sensors

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**4** 

*Ryerson University* 

*Canada* 

**The Application of Magnetic Sensors** 

Nowadays, GPS (Global Positioning System) has been widely used to position airplanes, ships, automobiles, migrating animals, and human beings, etc. However, GPS has its own limitations. Other than the user groups for whom GPS is operated, there is no service level agreement with anyone else. As more and more people become dependant on GPS in more and more countries, the political control of GPS raised doubt about its value. Moreover, in the event of system failure, equipment depending on GPS, such as airplanes or ocean-going vessels, needs alternative positioning systems. Furthermore, GPS relies on complicated infrastructure and cannot provide sufficient accuracy, stability and coverage for environments such as indoors and highly urbanized areas (known as "urban canyon") due to the lack of lineof-sight (LOS) to the satellites of GPS. As a result, most commercial and social activities taking

place in such environment can not benefit from positioning services offered by GPS.

Local positioning systems (LPS) are intended to provide a back-up for applications where GPS does not perform sufficiently to the requirements of the users. As indicated by the name, LPS can only provide positioning services within a limited area. Unlike GPS, LPS provides positioning services in communities, campuses, urbanized areas and inside buildings. LPS can be categorized into two groups: indoor positioning systems and outdoor positioning systems. The former provides positioning services inside buildings while the

LPS can provide positioning services in a wide range of applications, including personal guidance, people-finding, mobile information, moving object management and so on. LPS is also essential for augmented reality and ubiquitous computation. Typical applications of LPS are as follows personal navigation assistances (PNA), personal guidance (PG), LPS

PNA is a portable electronic device with both positioning function and navigation capability. A PNA based system is more flexible than GPS in providing optimal route descriptions for pedestrians because they only rely on the same maps for both in-vehicle and on-foot scenarios. On the other hand, as an interactive portable device, PG can help people with effective routing, or real-time reservation, and journey updating to inform the concerned parties of the latest situation on the journey. With this service, traveling will be

**1. Introduction** 

latter provides the services outdoors.

easier and safer for people.

tags, people-rescue and intelligent transportation services (ITS).

**in Self-Contained Local Positioning** 

Chengliang Huang and Xiao-Ping Zhang
