Location Awareness - Variants

Variants

"Crisp" locating offers precise coordinates, using wireless signals or optical sighting, possibly with phase angle measurements. Coordinates are relative to either a standardized system of coordinates, e.g. WGS84, or a fixed object such as a building plan. Real-time locating adds timely delivery of results, especially for moving targets. Real time locating is defined with ISO/IEC 19762-5 and ISO/IEC 24730-1. Fuzzy locating offers less precision, e.g., presence "near" a point of reference. Measuring wireless power levels can supply this degree of precision. Less sophisticated systems can use wireless distance measurements to estimate a point of reference in polar coordinates (distance and direction) from another site. Index locating indicates presence at a known location, as with fixed RFID readers and RFID tags.