NARDA NBM-550 - Page 148

14 Glossary
138 NBM-550 Narda
Average The average (mean) value formed from a range of
numerical values or measurements. For high frequency
electromagnetic fields, RMS (root mean square) averaging
is used for determining field strength values (V/m, A/m)
and linear averaging for power density values
(W/m
2
, mW/cm
2
).
DGPS Differential GPS
Method of improving the accuracy of GPS navigation by
transmitting correction data (orbit and time system).
E-field Electric field
Electric fields emanate from electrical charges or are
caused by induction in changing magnetic fields. Electric
field strength is expressed in volts per meter: E = [V/m].
EGNOS European Geostationary Navigation Overlay Service
European system comparable with DGPS for improving
the position accuracy of GPS from 10 to 20 meters to
1 to 3 meters. It also warns users when the positioning
systems are transmitting incorrect data or if the integrity of
the GPS data is restricted for some other reason. EGNOS
is fully compatible with the American WAAS system.
EMC Electromagnetic compatibility
Electromagnetic compatibility (EMC) describes the
technical and legal aspects of electrical engineering
covering the interactions between electrical equipment
due to the electromagnetic fields that they generate.
GPS Global Positioning System
The Global Positioning System is a satellite supported
navigation system belonging to the US Defense Ministry
that is used for determining the position of any location in
the world.