Systems for locating and tracking users or goods within cosed or open environments are of great interest for the human society as well as for world economy. Typical applications are e.g. emergency services and avalanche victim search or in mobile computing applications, tracking of goods and any location-aware services.

Typical applications:

• pervasive computing
  
• location-sensitive content delivery
  
• direction finding
  
• asset tracking
  
• emergency notification (e911 in USA)
  
• locate avalanche victims

Principles used for locationing
Basic methods and their classification