ADCP out of bounds errors

[j-atkins]

cc @erikvansebille @ammedd

As noted in class, the ADCP instrument sometimes gets unexpected out-of-bounds errors. I've diagnosed that this is due to a mismatch in the ship route vs. the waypoint locations (likely stemming from the methods in simulate_schedule).

This can be seen in the example expedition below (the same expedition shared by the student group). The underway instruments want to make measurements along the blue track but the fieldset boundaries (black box) are determined by the waypoint locations (red markers), hence there is an out-of-bounds error in this case (at the eastern edge).

Note, this is therefore also likely to be a bug for the underway UnderwaterST instrument.

I'll look deeper into the ship routing methods to see why this is happening.

[j-atkins]

Update: this appears to be due to the fact that the azimuth bearing is calculated as the direction to propel the ship to the next waypoint but then it simply travels straight along that bearing without accounting for curvature of the globe, so actually waypoints are 'missed' and this is of course most pronounced when there's longer distances between waypoints (as seen in the image in my original comment).

I'm working on a fix now which will set the ADCP measurement locations across the right path and look more like this: