5.2.7 Heading indication
When inside the field of view, the heading marker of the craft should be indicated on the display with an error not greater than ± 1°.
When outside the field of view, a visual indication of relative bearing with an error of not greater than ±1°should be provided.
5.2.8 Roll or pitch
The performance of the night vision equipment should be such that when the craft is rolling and/or pitching up to ±10°, the performance requirements in this standard should be complied with.
5.2.9 Clear view
Arrangement should be provided to ensure efficient cleaning of the sensor head/lens from the operating position. Administrations may require some additional facilities such as de-icing.
5.2.10 Optical interference
Measures should be taken, to ensure that objects commonly encountered at sea and in ports should not be displayed less clearly on the monitor of the night vision equipment because of dazzle effects, reflection, blooming, or any other effects due to the surroundings.
5.3 MALFUNCTIONS, ALARMS AND INDICATIONS
The night vision equipment should include a visual indication of any failure.
5.4 SOFTWARE REQUIREMENTS
5.4.1 The operational characteristics of the software should meet the following requirements, in particular:
.1 self-description of the functions implemented by means of software;
.2 display of user interface status; and
.3 software protection against unauthorized changes.
5.4.2 If certain functions of night vision equipment are implemented using software, such software should meet the applicable requirements of international standards*.
6 ERGONOMIC REQUIREMENTS
6.1 GENERAL
The night vision equipment should be designed in accordance with sound ergonomic principles.
*Refer to IEC Publication 60945
