4.1 The Galileo receiver equipment should also
indicate whether the performance of Galileo is outside the bounds
of requirements for general navigation in the ocean, coastal, port
approach and restricted waters, and inland waterway phases of the
voyage as specified in either resolution A.953(23) or Appendix 2 to
resolution A.915(22) and any subsequent amendments as appropriate.
The Galileo receiver equipment should as a minimum:
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.1 provide a warning within 5 s of loss of position
or if a new position based on the information provided by the Galileo
constellation has not been calculated for more than 1 s for conventional
craft and 0.5 s for high-speed craft. Under such conditions the last
known position and the time of last valid fix, with the explicit indication
of the state so that no ambiguity can exist, should be output until
normal operation is resumed;
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.2 use receiver autonomous integrity monitoring
(RAIM) to provide integrity performance appropriate to the operation
being undertaken;
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.3 provide a self-test function.
4.2 For receivers having the capability to process
the Galileo Safety of Life Service, integrity monitoring and alerting
algorithms should be based on a suitable combination of the Galileo
integrity message and receiver autonomous integrity monitoring (RAIM).
The receiver should provide an alarm within 10 s Time to Alarm (TTA)
of the start of an event if an alert limit of 25 m Horizontal Alert
Limit (HAL) is exceeded for a period of at least 3 s. The probability
of detection of the event should be better that 99.999% over a 3-h
period (integrity risk <= 10-5/3 h).