Topcon AGA5495, Operator'S Manual, Page: 137 / 144

Chapter 18 – Appendices
119
Latitude The distance of a position north or south of the equator
measured in degrees.
One minute latitude is equal to one nautical mile (1852
m). The equator has a latitude of zero.
Longitude The distance of a position east or west from the prime
meridian measured in degrees. The prime meridian runs
through Greenwich, England and is zero longitude.
Mobile
Base
Station A base station that can be easily moved and can
independently determine its new position so that it can
then continue working with the DGPS system.
Mounting
Bias Mounting bias refers to whether the receiver is exactly
level, when installed.
MSAS (Multi-functional Satellite Augmentation System) This
is a Japanese SBAS which supplements the GPS by
reporting and improving on the reliability and accuracy
of the GPS signals.
NMEA (National Marine Electronics Association) This is a
standard protocol used by electronic devices to receive
and transmit data.
OmniSTAR A commercial service that receives GPS signals from
NAVSTAR, checks them for errors and then uploads
the error correction data to the OmniSTAR satellites.
Reference
Station A GNSS receiver that supplies differential corrections
to receivers equipped with GNSS. Also called a base
station.