5 Requirements for integration of navigational information

  5.1.1 An INS should combine, process and evaluate data from connected sensors and sources.

  5.1.2 The availability, validity and integrity of data exchange within the INS and from connected sensors and sources should be monitored.

  5.1.3 A failure of data exchange should not affect any independent functionality.

  5.1.4 Interfacing to, from, and within the INS should comply with international standards for data exchange and interfacing as appropriate.

  5.1.5 The interface(s) should comply with the interface requirements of the alert management as described in Module C of these performance standards.

  5.2.1 INS data should comply with the accuracy and resolution required by applicable performance standards of the Organization.

  5.3.1 Validity

  5.3.1.1 Data failing validity checks should not be used by the INS for functions dependent on these data, unless for cases where the relevant performance standards specifically allow use of invalid data. There should be no side effects for functions not depending on this data.

  5.3.1.2 When data used by the INS for a function becomes invalid, or unavailable, a warning should be given. When data not actually in use by the INS becomes invalid, or unavailable, this should be indicated at least as a caution.

  5.3.2 Plausibility

  5.3.2.1 Received or derived data that is used or distributed by the INS should be checked for plausible magnitudes of values.

  5.3.2.2 Data which has failed the plausibility checks should not be used by the INS and should not affect functions not dependent on these data.

  5.3.3 Latency

  5.3.3.1 Data latency (timeliness and repetition rate of data) within the INS should not degrade the functionality specified in the relevant performance standards.

  5.4.1 Consistency of data

  5.4.1.1 The INS should ensure that the different types of information are distributed to the relevant parts of the system, applying a “consistent common reference system” for all types of information.

  5.4.1.2 Details of the source and the method of processing of such data should be provided for further use within INS.

  5.4.1.3 The CCRS should ensure that all parts of the INS are provided with the same type of data from the same source.

  5.4.2 Consistent common reference point

  5.4.2.1 The INS should use a single consistent common reference point for all spatially related information. For consistency of measured ranges and bearings, the recommended reference location should be the conning position. Alternative reference locations may be used where clearly indicated or distinctively obvious. The selection of an alternative reference point should not affect the integrity monitoring process.

  5.4.3 Consistency of thresholds

  5.4.3.1 The INS should support the consistency of thresholds for monitoring and alert functions.

  5.4.3.2 The INS should ensure by automatic means that consistent thresholds are used by different parts of an INS, where practicable.

  5.4.3.3 A caution may be given when thresholds entered by the bridge team differ from thresholds set in other parts of the INS.

  5.5.1 The integrity of data should be monitored and verified automatically before being used, or displayed.

  5.5.2 The integrity of information should be verified by comparison of the data derived independently from at least two sensors and/or sources, if available.

  5.5.3 The INS should provide manual or automatic means to select the most accurate method of integrity monitoring from the available sensors and/or sources.

  5.5.4 A clear indication of the sensors and sources of data selected for integrity monitoring should be provided.

  5.5.5 The INS should provide a warning, if integrity verification is not possible or failed.

  5.5.6 Data which fails the integrity monitoring function or data where integrity monitoring is not possible should not be used for automatic control systems/functions.

  5.6.1 The data should be marked with the source and the results of validity, plausibility checks and integrity monitoring to enable subsequent functions to decide whether their input data complies with their requirements or not.

  5.7.1 INS should provide two user selectable sensor/source selection modes when multiple sensors/sources are available; manual sensor/source selection mode and automatic sensor/source selection mode.

  5.7.2 In manual sensor/source selection mode it should be possible to select individual sensors/ sources for use in the INS. In case a more suitable sensor/source is available this should be indicated.

  5.7.3 In automatic sensor/source selection mode, the most suitable sensors/sources available should be automatically selected for use in the INS. It should further be possible to manually exclude individual sensors/sources from being automatically selected.