Use the MEAL localiser with vector GPS data.
In the last exercise we used a vertical array which we assumed was stationary and determined a porpoise dive profile. In real life it is possible we will be using an array which is not stationary. If this is case there are two vital pieces of information needed to relate localisation information to real world co-ordinates, the heading and latitude/longitude of the array.
Open PAMGUARD viewer mode and select the database VertQuad in the Exercise 4 folder. Open the binary file folder 20120715.
In order to use GPS data you need to add the GPS module. Go to File > Add Modules > Maps and Mapping and add NMEA Data Collection, GPS Processing and Map. You should see the Map tab appear in PAMGUARD.
To add GPS data go to Detection > GPS > Import GPS Data....
In the dialog box open the NMEA file in the Exercise 4 folder. A dialog box will appear asking you to select a date. Ignore this, tick Use only GPRMC strings and click OK .
Wait until the GPS data has loaded
Select the map. You should see GPS tracks. Use the slider to move the position of the vessel. You may need to use the scroll bars to load more hours of data into memory.
Figure 27. After successfully importing GPS data you should be able to view the ships’ tracks and heading in the MAP.
Now select the MEAL localiser module and find a suitable porpoise detection. Localise using one of the algorithms. You will notice a realistic GPS position in the results panel
Figure 28. The MEAL localiser will automatically import GPS data and convert localisation results to a real lat/long.