Meinberg GPS167LCD-MP - Manual (Page 9)

9
The Modular System GPS167LCD-MP
GPS167LCD-MP GPS-Receiver is a set of equipment composed of a satellite control-
led clock GPS167 (LQ-OCXO) together with a power supply unit Mean Well T-60B,
both installed in a metal desktop case MULTIPAC and ready to operate. The inter-
faces and input/output signals provided by GPS167 are accessible via connectors in
the rear and the front panel of the case. Details of the components are described below.
LOCK
CLR/ACK NEXT INC
FAIL
MENU LIGHT
GPS167 LCDMP
satellite controlled
GPS167LCD-MP GPS-Receiver in desktop case MULTIPAC (front view)
GPS167 Features
The front panel integrates a 2 x 40 character LC display, two LED indicators and five
push buttons. The receiver is connected to the antenna/converter unit by a 50 ohm
coaxial cable (refer to "Mounting the Antenna"). Feeding the antenna/converter oc-
curs DC insulated via the antenna cable. Optional an antenna splitter for up to four
receivers connected to one antenna is available.
GPS167 is using the "Standard Positioning Service" SPS. The altitude with its
variation of ±180m is the most inaccurate component of the position. This inaccuracy
is caused by the operator (United States Departement of Defense) and not by the
GPS167, but it has no influence on the accuracy of the generated time. The navigation
message coming in from the satellites is decoded by GPS167´s microprocessor in
order to track the GPS system time. Compensation of the RF signal´s propagation
delay is done by automatical determination of the receiver´s position on the globe. A
correction value computed from the satellites´ navigation messages increases the
accuracy of the board´s oven controlled master oscillator (OCXO)
and automatically
compensates the OCXO´s aging. The last recent value is restored from the battery
buffered memory at power-up.
Time Zone and Daylight Saving
GPS system time differs from the universal time scale UTC (Universal Time Coordi-
nated) by the number of leap seconds which have been inserted into the UTC time
scale after GPS has been initiated in 1980. The current number of leap seconds is part
of the navigation message supplied by the satellites, so GPS167´s internal real time is
based on UTC. Conversion to local time including handling of daylight saving year by
year can be done by the receiver´s microprocessor if the corresponding parameters are
set up by the user.