Glossary
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GMDSS Global Maritime Distress Safety System. The system is intended
to perform the following functions: alerting (including position
determination of the unit in distress), search and rescue
coordination, locating (homing), maritime safety information
broadcasts, general communications, and bridge-to-bridge
communications.
GND Ground
GPI General Purpose Input
GPO General Purpose Output
H
Hdop Horizontal dilution of precision. Precision of 2D position on
Earth’s surface, without height indication. This is typically better
than Pdop.
I
IMO International Maritime Organization. A UN organization
developing and maintaining regulatory framework for shipping.
This framework includes safety, environmental concerns, legal
matters, technical co-operation, maritime security and the
efficiency of shipping.
IMSO International Mobile Satellite Organisation. An
intergovernmental organisation that oversees certain public
satellite safety and security communication services provided
via the Inmarsat satellites.
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