EndRun Meridian II, Руководство пользователя

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M e r i d i a n I I U s e r M a n u a l 1
"Smarter Timing Solutions"
Chapter
One
Introduction
The Meridian II Precision TimeBase is a high-performance, full-featured system that provides highly-
precise time and frequency outputs. The modular design allows for easy, field-installed upgrades that
can satisfy virtually any time and frequency requirement. Advanced packaging techniques, coupled
with compact card design, allow for the installation of up to five option boards in a single 1U or 2U
chassis.
Using a proprietary Global Positioning System (GPS) timing receiver, the Meridian II supports
operation in static or dynamic (shipboard only) platforms. Proprietary multiple satellite optimal
ensembling, adaptive 3rd order frequency control and TRAIM algorithms maximize the accuracy,
stability, and reliability of the output signals. A variety of top-quality quartz and rubidium oscillators
are available to handle the full range of holdover, phase noise, and short-term stability requirements.
Units equipped with our Ultra-Stable OCXO provide unmatched close-in phase noise performance
and short-term stability.
The Meridian II uses GPS transmissions to precisely synchronize its clock within 10 nanoseconds of
Coordinated Universal Time (UTC). The frequency of the internal oscillator is disciplined to match
the frequency of the UTC timescale to less than 1 part in 10
13
over 24-hour observation intervals.
The time and frequency outputs are coherent after initial GPS synchronization and maintained via
20-bit DAC frequency control, rather than phase stepping, to provide excellent short-term stability.
For more detailed information that is not included in this manual, and links to other sites, please visit
our website:
http://www.endruntechnologies.com
. There you can also download firmware upgrades,
the latest manuals and other documentation.
Main Features
Robust GPS Receiver
Meridian II is a GPS-based time and frequency standard designed to support mission critical applica-
tions. The proprietary GPS timing receiver in Meridian II has many safeguards to protect against
false GPS signals. The receiver strictly adheres to the GPS Interface Specification and performs
low-level integrity checks to protect against weak corrupted signals, jamming, spoofing and acciden-
tal GPS control system errors. EndRun’s GPS timing receiver technology has evolved to be highly
robust against these threats to provide time and frequency outputs you can trust.
Highly-Reliable, Modular Design
The Meridian II provides high performance and reliability combined with low power consumption
and cost. Its internal sub-assemblies are fabricated using state-of-the-art components and processes
and are integrated in a solid, high-quality chassis. Since it uses highly efficient ARM microproces-