Streamer Dialog
Hydrophone Array
New Streamer Dialog
The Streamer dialog has changed in release 1.13.
The Streamer name is for information purposes only.
Reference Position
Streamer locations can be referenced to either the “Ships GPS Data” or to “Fixed location (moorings and buoys)”. If GPS data is selected then the system will automatically connect to data from the GPS Module. If a fixed location is selected, then additional options will appear allowing you to enter a reference Latitude and Longitude.
To change the position, use the menu on the button to the right of the displayed location. It is possible to enter a new value manually, take the current GPS position or to paste in the last location clicked on the PAMGuard map.
Hydrophone Locator Method
Two methods are available for calculating true hydrophone coordinates from the reference position. These are the “Threading Streamer” locator and the “Straight / Rigid Streamer” locator.
The Threading system is most applicable to towed hydrophone systems referenced to ship GPS data. It assumes that the streamer cable exactly follows the track of the vessel as it goes round corners. However, for hydrophones mounted rigidly on the hull of a vessel it would be more sensible to use the Straight / Rigid method.
If the reference position is a fixed location, then it only makes sense to use the Straight / Rigid method.
Hydrophone Coordinates
Enter the hydrophone coordinates in metres relative to the reference position.
Also enter estimates of the errors on those coordinates.
Orientation data
For GPS referenced locations, if these values are not null, they will override heading values from the GPS data. If they are null, then the GPS values will be used. Some users are starting to collect orientation data for hydrophones which can give a more accurate position than relying on the threading hydrophone model. No systems for collecting these data are yet built into PAMGuard and have to date only been imported during offline analysis of data. Expect further developments in this area in the near future !
Interpolation
Things sometimes move ! As we start to incorporate sensors into our arrays, it will be necessary to chose how to pick a position from a list of evolving positions over time.
These options tell the system to take the latest value entered by the user, to interpolate between values bracketing the time of an event or to use the values immediately preceding an event.