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INTERFACE REQUIREMENTS

IEC 61996 provides detailed information on the required data sets for
VDR and S-VDR. The following is a summary. The following items are
required for both VDRs and S-VDRs:

Date and Time. Date and time, referenced to Coordinated Universal Time
(UTC), obtained from a source external to the ship or from an internal
clock at least once per hour. The recording must indicate which source is

in use. The recording method must be such that the timing of all other
recorded data items can be derived on playback with a resolution
sufficient to reconstruct the history of the incident in detail.

Ship’s Position. Latitude and longitude, up to a resolution of 0.00001
minutes of arc, and the datum used. The identity and status of the source
must be recorded so that they can be determined on playback.

Speed. Speed through the water or over the ground, up to a resolution of
0.1 knot, with an indication of which is being used.

Heading. Ship’s heading with a resolution up to 0.1 degrees, as derived
from the ship’s compass.

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