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4 General information about GNS165
4 General information about GNS165
The Meinberg satellite receiver clock of the GNS165 series is available with several options. This manual
describes the following models:
GNS165DHS
GNS165DAHS
GNS165/AQ/DHS
GNS165/AQ/DAHS
20-60 V DC 100-240 V AC 100-240 V DC
PhotoMos
relay outputs
Optocoupler
outputs
GNS165DHS GNS165DAHS
The variants differ in power supply and the type of DC-isolation of the programmable pulse outputs. The
differences are described in the relevant chapters, the name GNS165 is used whenever common features of all
types of clocks are specified.
The satellite receiver clock GNS165 has been designed to provide an extremly precise time reference for
the generation of programmable pulses. High precision available 24 hours a day around the whole world is
the main feature of the new system which receives it’s information from the satellites of the Global Positioning
System.
The satellites of most Global Navigation Satellite Systems (GNSS) like GPS , GLONASS , and Galileo are
not stationary but circle round the globe in periods of several hours. Only few GNSS systems like the Chinese
Beidou system work with stationary satellites. Such systems can only be received in certain regions of the Earth.
GNSS receivers need to track at least four satellites to determine their own position in space (x, y, z) as
well as their time offset from the GNSS system time (t). Only if the receiver can determine its own position
accurately the propagation delay of the satellite signals can also be compensated accurately, which is require-
ment to yield an accurate time. If the receiver position can only be determined less accurately then the accuracy
of the derived time is also degraded.
GNS165DHS / GNS165DAHS Date: 19th January 2021 15