VDR Plugin

[Antipole]

Originally Posted by Pearson 39-II

Antipole: This CruisersForum is much more public and well known and easy to use. Would you consider opening your own VDR2 thread within the OpenCPN forum ?

The problem with this forum is that each is a single thread and unstructured. There is no way of omitting obsolete entries. For example, if an issue is fixed, later readers still have to wade through it.
Discussions and Issues on GitHub are structured and can be marked as closed.
So, I will stay with GitHub for VDR2.

[petter5]

Regarding the VDR plugin, would this be possible:


If using OpenCpn in a patrol boat whee you have a AIS receiver and using the VDR plugin, I want to record tracks for all individual vessels /mmsi numbers within the range of the AIS receiver at any time, later be able to find and replay the AIS track message for a single or selected individual vessel(s) / at a given date / time /range and also export these data for this vessel to a file to be used for VDR reply. Can this be done ?

[nohal]

Not simply at NMEA0183 level as the AIS binary messages must first be individually decoded to know to which MMSI they relate.
Probably better to implement a tool for just this purpose, maybe with a database backend storing the NMEA messages with the basic metadata (at least MMSI and timestamp) for simple filtering. That tool then could produce filtered logfiles that could be replayed by the VDR plugin or directly produce a TCP/UDP data stream.

[Antipole]

VDR2 is about recording your own boat and does not do what you want.

However, it would be simple to write some JavaScript to do what I think you want. A script has access to the decoded AIS targets and could write your required parameters to log files - maybe a separate file for each MMSI. See the plugin User Guide p30 for the OCPNgetAISTargets() API.

If you want to discuss or get more help, start a topic on the JavaScript plugin discussions here.

[petter5]

I did open a thread in GITHUB

Originally Posted by Antipole

VDR2 is about recording your own boat and does not do what you want.

However, it would be simple to write some JavaScript to do what I think you want. A script has access to the decoded AIS targets and could write your required parameters to log files - maybe a separate file for each MMSI. See the plugin User Guide p30 for the OCPNgetAISTargets() API.

If you want to discuss or get more help, start a topic on the JavaScript plugin discussions here.

[stevead]

If using OpenCpn in a patrol boat...I want to record tracks for all individual vessels /mmsi numbers.... replay the AIS track message for a single or selected individual vessel(s....

As others have said, neither the VDR plugin or the VDR2 Java script are suited to this task and another approach or tool would have to be developed.

However from the gist of the question, it seems as though the requirement is for law enforcement purposes. Given that under SOLAS regulations, specific vessels are required to carry certified Voyage Data Recorders, the information from which can be used in legal matters, it seems as though you are interested in recording voyage details for vessels that are not obliged to carry VDR's.

How do you plan on ensuring that your recorded AIS data cannot be repudiated in legal proceedings?

As many of us with expertise in both cyber security and marine communications systems know, there is no security inherent within these systems. It would be very easy to demonstrate that AIS data could be fabricated or that its integrity has been compromised during subsequent processing and storage within your system.

You may be able to provide evidence of a ship's presence via recorded AIS, however I could provide otherwise from my own "recorded" voyage data thereby causing "reasonable doubt"

[Antipole]

@petter5 You are in luck. We were storm-bound in Egersund, so I wrote you a JavaScript for what I think you want.

AISrecord monitors AIS targets and records movement of each target to a separate file. These files can be played back with the VDR plugin.

The script can be configured to record all targets or just those within a chosen range of you.

You can also set the distance a target needs to move before a new record is made. This avoids multiple records for stationary targets or those swinging at anchor.

More details in the script's repository here.

You need the JavaScript plugin v3.0.6 or later. This version has been submitted for inclusion in the plugin catalogue directory but there seems to be some delay in updating the catalogue. If you only see v3.0.5, you can download v3.0.6 from its repository here.

[petter5]

Whoow and many thanks. Some question: Do the script log the complete AIS sentences from the targets like rate of turn, speed, bearing and so on ?

[Antipole]

Originally Posted by petter5

Whoow and many thanks. Some question: Do the script log the complete AIS sentences from the targets like rate of turn, speed, bearing and so on ?

To avoid going off the VDR topic here, please raise queries in the script’s discussion forum here.

Please read the README and try the script out to familiarise yourself with what it does now before raising queries.