ng on instrument orientation, is
mapped onto a "mast" coordinate that points more nearly upwards than
downward.  The other ship coordinates are called "starboard" and "forward",
the meanings of which will be clear to mariners.  Once the (x,y,z)
velocities are converted to ship velocities, the orientation of the
instrument is extracted from heading, pitch, and roll vectors stored in the
object.  These angles are defined differently for RDI and Sontek profilers.</p>
<p>The code handles every case individually