Recorded Data Analysis
Common Recorded Data
Date and Time (GPS): Date and time referenced to UTC, and is received from a source external to the ship (i.e an EPFS or radio time signal if available), or from an internal clock at least once per hour. During the recording process in MAESTRO S-VDR / VDR it is illustrated which source is in use. It should be noted that the recording method is such that the timing. [MSC.163(78) 5.4.1]
Ship’s Position (GPS): Latitude and longitude, and the datum used, is derived from a designated EPFS or INS if available on ship. It is important to be ensured that the identity and status of the source can always be determined on playback with the suitable replay equipment. Furthermore, the Ship’s Position is recorded, as available on the ship to a resolution of 0.0001 min of arc. [MSC.163(78) 5.4.2]
Speed (Speed Log): It is associated with Speed through water or speed over the ground (transverse as well as longitudinal in either case, as available on the ship), including an indication from which it is, derived from the ship’s designated speed and distance measuring equipment, is recorded as available on the ship up to a resolution of 0.1 kn. [MSC.163(78) 5.4.3]
Heading (Gyro Compass): Heading refers to as indicated by a designated ship’s compass. The ship’s heading is recorded, as available on the ship, up to a resolution of 0.1o. [MSC.163(78) 5.4.4]
Bridge Audio: One or more microphones positioned on the bridge is placed, such that conversation at or near conning stations, radar displays, chart tables etc. (for example at workstations) may be adequately recorded. As far as is practical, the position of the microphones should also capture the input and output of intercom, public address systems and the audible alarms on the bridge (bridge mounted equipment). The audio signals at all work stations should be recorded continuously. Optionally, means may be provided so that the originating work station can be identified with the audio signal being analysed during playback of the recorded information. [MSC.163(78) 5.4.5]
Communication Audio: VHF Communications relating to ship operations is recorded, independently of the bridge audio. It should be marked that the recording include both transmitted and received audio signals and should be continuous form a directly connected fixed VHF radio to be designated at installation of MAESTRO S-VDR / VDR. [MSC.163(78) 5.4.6]
Radar Data / Post Display Selection: In particular this includes electronic signal information from within one of the ship’s radar installation which records all the information which was actually being illustrated on the master display of that radar at the time of recording. This is includes any range rings or markers, bearing markers, electronic plotting symbols, radar maps, whatever parts of the SENC or other electronic chart or map that were selected, the voyage plan, navigational data, navigational alarms and the radar status data that were visible on the display. The recording method should be such that, on playback, it will be possible to present a faithful replica of the entire radar display that was on view at the time of recording, albeit within the limitations of any bandwidth compression techniques that are essential to the working of the S-VDR / VDR. [MSC.163(78) 5.4.7]
A.I.S (Automatic Identification System): In cases where the is no commercial off-the-shelf interface available to obtain radar data then AIS target should be recorded as a source of information regarding other ships ; otherwise AIS information can be recorded additionally as a beneficial secondary source of information on both other and own ship.
It should be mentioned that the VDM message is recorded in such a way, that all target data available from the onboard AIS are acquired.
In case where the VDO message is recorded, this should be additional to the recording of individual sensor data. [MSC.163(78) 5.4.8]
Other Recorded Data
Furthermore, S-VDR / VDR will record any additional item listed by IMO A.861 (20) 4.6.10 – 4.6.17 in case the data are already available in accordance with the international interface standards using approved sentence formatters.
In particular, Echo Sounder / Main Alarms / Rudder Order and Response / Engine Order and Response / Hull Opening (Doors) Status / Watertight and Fire Door Status / Accelerations and Hull Stresses / Wind Speed and Direction. [MSC.163(78) 5.4.9]
Echo Sounder: In particular recording depth under keel, up to a resolution of 0.1ms as available on the vessel. The depth scale currently being displayed and other status information will be recorded where available.[IMO A.861(20) 5.4.8]
Main Alarms: Main Alarms are comprised all IMO mandatory alarms on the bridge. The status of all IMO mandatory alarms will be recorded by the bridge audio and as a data parameter where practicable. Refer to ANNEX D. [IMO A.861(20) 5.4.9]
Rudder Order and Response: Specifically both rudder order and response angles is recorded up to a resolution of 1 degree as available and permitted on the ship. Status and Settings of Heading or track controller, if fitted is also recorded. [IMO A.861(20) 5.4.10]
Engine Order and Response: It includes the positions of any engine telegraphs or direct engine / propeller controls, including shaft(s) (revolutions or equivalent), and feedback indications, if fitted, including ahead/astern indicators. This shall also include status of bow and stern thrusters if fitted. Revolutions is recorded up to a resolution of 1 rpm and pitch is recorded up to a revolution of 1o. [IMO A.861(20) 5.4.11]
Hull Opening (doors) status: All IMO Mandatory Status information required displayed on the bridge is recorded. [IMO A.861(20) 5.4.12]
Watertight and fire door status: All IMO Mandatory Status information required to be displayed on the bridge. [IMO A.861(20) 5.4.13]
Acceleration and Hull Stresses: In particular where the ship is fitted with IMO mandated hull stress and response monitoring equipment, all the data items that have been pre-selected within that equipment and are available are recorded. [IMO A.861(20) 5.4.14]