Deploying Sonobuoys
DIFAR Localisation
Hydrophone array configuration
Arrays of DIFAR sonobuoys are fundamentally different than towed arrays. In PAMGuard each DIFAR sonobuoy is assigned to a streamer using the Array Manager. The Array Manager can be accessed via the Deploy button on the DIFAR Queue.
Presently streamers for DIFAR sonobuoys should be configured using a “Fixed location” for the reference position, and a “Straight/Rigid Streamer”. An independent streamer is required for each sonobuoy when recording from multiple sonobuoy simultaneously (i.e. the number of streamers should be equal to the number of radio receivers used to receive signals from sonobuoys). The following image shows one of the streamers from a three-sonobuoy array.
Deploying
The Deploy button on the DIFAR Queue can be used when physically deploying a new sonobuoy. Clicking the Deploy button will open a menu allowing options to deploy a new buoy on any of the existing streamers that have been configured in the Array Manager. Upon selecting one of these menu items, a new Streamer Dialog window will appear.
The Streamer Dialog window will contain the GPS position of the ship at the time when the “Deploy channel” menu item was selected. If any of the streamers in the Array Manager have a numeric Streamer Name, then this will be used to automatically name the newly deployed streamer using the next sequential number. Thus, using the Deploy button is used to deploy all sonobuoys will result in sonobuoys names being sequential numbers.
Sonobuoys can be assigned alternative names, deployment numbers, or station numbers by typing directly into the Streamer Name.
Sonobuoy deployments will be stored in the PAMGuard database under the HydrophoneStreamers table.
In addition to a Deploy button, versions of PAMGuard after 1.15.05 also have an button titled Buoy Finished which will add a timestamp in the EndTime column of the database for the selected deployment. Aside from this timestamp in the database, the Buoy Finished button has no effect on the operation of PAMGuard’s DIFAR module, the Array Manager, or any other aspect of PAMGuard.
Sonobuoy Manager
A ‘Sonobuoy Manager’ was added to the DIFAR module after PAMGuard version 1.15.05. The sonobuoy manager allows limited viewing and editing of sonobuoy metadata in normal, mixed, and viewer mode, and can be added to a User Display via the User Display menu. Presently, the DIFAR module only allows one Sonobuoy Manager window to exist.
Sonobuoys that have been edited via the Sonobuoy Manager will be updated both within PAMGuard modules (e.g. ArrayManager, Map, DIFAR Localisaiton Module, etc), and their corresponding entries in the PAMGuard database will be OVERWRITTEN. Thus users should exercise caution when using the Sonobuoy Manager and are encouraged to make backups of their database (NB: Sonobuoy metadata is stored in the HydrophoneStreamers table of the database).
