How to prepare your tracks for polar calculation

Statistical calculation of the speed of a sailboat requires accurate tracking data. These data allow to generate reliable polar diagrams of your own boat. To obtain the most precise speed targets, it is necessary to calibrate your instruments and to extract the periods of navigation under sail. 

All along your navigations, Adrena permanently records data from the instruments and save them as tracks. These tracks constitute the database from which the best performances will be extracted in order to create polar diagrams.

Some “markers” are used to differentiate sail periods from engine periods. Here are the methods to create these markers:

Method 1:

Go to Performance menu and use the dedicated buttons to specify the conditions of navigation:

Click on the “sail mode” button when you are navigating under sail and click on the “engine mode” when you are navigating with the engine.

Click on the above button each time the boat speed is considered as a speed target according to the wind conditions (force and direction). Thus the software takes into account this specific data whatever the data purification used for the calculation is.  

The sea state can be specified thanks to these icons: calm sea, moderate sea or rough sea. If you want to generate your polars regardless of the sea state, this setting can be ignored. On the contrary, if you want to include this information in your polar calculation, click on the corresponding icon each time you strat navigating – this information can be modified during your navigation if the sea state is changing.


Method 2

Data can also be modified afterwards, in particular if you forgot to click on the “sail mode” button  when your were sailing or if you did not stop it when you put the engine on.

To modify data, go to “Performance -> Correction of recordings” and select the tracks to be modified. It opens the correction of recordings window.

Select the time slot to be modified as well as the type of correction to be made:

“Force the “under sail” mode”: to specify that the boat was under sail on the indicated time slot and that the corresponding data are to be taken into account in polar calculation.

Force the “engine powered” mode: to specify that the boat was under engine on the indicated time slot and that the corresponding data are not to be taken into account in polar calculation.

Delete the “preferred speed” settings: to delete the top speed data selected during the indicated time slot. Be careful: the operation cannot be undone.

Other markers are available in order to specify some weather conditions on a given track period:

Force “calm sea”, “choppy” or “rough sea”: to specify the sea state on the indicated time slot.

Range Pro only:

To change the boat configuration (sails, foils, etc.): click on the 

button and modify the corresponding elements.

Once the modifications are selected, click on the “launch” button to start the operation. Thus the software looks for the related data to be modified and correct them.


Method 3:

The correction of a recording can also be made directly on the track: right click on the track at the beginning of the period to be corrected, click on “Track” -> “Correct the recoding” then click on the end of the period to be corrected and proceed as illustrated below.

The tracks to be corrected are displayed in bold to differentiate the periods under sail from the periods under engine (made automatically in range First and to be activated in Standard and Pro ranges)

If this method of track correction is regularly made, this allows the generation of reliable polar diagram more quickly.