5 OPERATIONAL REQUIREMENTS
5.1 Functionality
At night, NVEE 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 safe navigation.
5.1.1 Continuous operation
NVEE equipment on board HSC while navigating at sea should be capable of continuous operation from after sunset until before sunrise.
After the NVEE has been switched on it should be operational in at most 15 minutes.
5.2 Accuracy
5.2.1 Range performance
The operational requirement, where the NVEE is mounted 7.5 m above sea level is that the NVEE should give a clear detection of the standard test target at a distance of at least 2 times the crash stop distance, or 500 meters whichever is the larger.
5.2.2 Range indication
An arrangement for range indication should be provided up to up to 2 times the crash stop distance, minimum 500 meters. The range resolution should be at least 100 meters up to 400 meters, and an appropriate resolution for ranges of more than 400 meters. The accuracy of the range indication should be 50 meters or better, for ranges of less than 300 meters, and 20% or better, for ranges of more than 300 meters.
5.2.3 Field of view
5.2.3.1 The horizontal field of view should be at least 27 degrees, 13.5 degrees on each side of the bow.
5.2.3.2 The vertical field of view should be sufficient to enable the equipment to fulfill the performance requirements of these standards.
5.2.4 Traverse mode range
5.2.4.1 The axis of the field of view should be capable of being moved at least 20 degrees horizontally to either side, starting from dead ahead.
5.2.4.2 The horizontal slew speed per second should as a minimum be the largest value of either, 2 degrees per second or 10% of the horizontal field of view.
5.2.4.3 The equipment should operate satisfactory in relative wind speed up to 100 knots.
