5.1 Required functions and their availabilityAt night, night vision equipment should be
capable of detecting objects above the water surface within a certain distance from
one's own craft, and of displaying the information pictorially in real time, to
assist in collision avoidance and safe navigation.
5.2 Reliability, accuracy and discrimination5.2.1 Continuous operation
Night vision equipment on board HSC, while
navigating at sea, should be capable of continuous operation from after sunset until
before sunrise. After the equipment has been switched on it should be operational in
less than 15 min.
5.2.2 Standard test
target
The standard test target should be a
black metal target of such a size that when at least 50% is immersed, 1.5 m long x
0.5 m high remains above the water at right angles to the desired direction of
detection. Administrations may use other smaller targets to reflect local
conditions.
5.2.3 Detection range
With the required field of view, the equipment
should detect the standard test target at a distance of not less than 600 m with a
minimum probability of 90%, when the target has been immersed in the sea for at
least 24 hours under mean starlight conditions without clouds and without moon.
5.2.4 Field of view
The required horizontal field of view should be at least 20º, 10º on
either side of the bow. The vertical field of view should be at least 12º and should
be sufficient to enable the equipment to fulfil the performance requirements of this
standard as well as being able to see the horizon. Optionally other fields of view
may be provided. Their selection should be made with a non locking switch, which
returns to the required field of view when released.
5.2.5 Pan and tilt ranges of the fields of view
The axis of the field of view of the equipment
should be capable of being moved at least 20º horizontally to either side. The
elevation axis of the field of view should be capable of being adjusted by at least
10º to compensate for the trim of the craft.
5.2.6 Speeds of panning of the fields of view
By activation of a single control element, the axis of the field of
view should be capable of being returned automatically to the ahead position at a
minimum angular speed of 30º/s. The system should be capable of panning at a minimum
angular speed of 30º/s
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 ± 1º. 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 ± 10º, 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 indicationsThe night vision equipment should include a
visual indication of any failure.
5.4
Software requirements5.4.1 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*.
* Refer to IEC Publication 60945