driftvel

Wind or current from heading, course, and speeds

Syntax

[windfrom,windspeed] = driftvel (course,groundspeed,heading,airspeed)

Description

[windfrom,windspeed] = driftvel (course,groundspeed,heading,airspeed) computes the wind (for aircraft) or current (for watercraft) from course, heading, and speeds. course and groundspeed are the direction and speed of movement relative to the ground (in degrees), heading is the direction in which the vehicle is steered, and airspeed is the speed of the vehicle relative to the air mass or water. The output windfrom is the direction facing into the wind or current (in degrees), and windspeed is the speed of the wind or current (in the same units as airspeed and groundspeed).

Examples

An aircraft is cruising at a true air speed of 160 knots and a heading of 10 degrees. From the Global Positioning System (GPS) receiver, the pilot determines that the aircraft is progressing over the ground at 155 knots in a northerly direction. What is the wind aloft?

course = 0; groundspeed = 155; heading = 10; airspeed = 160;
[windfrom,windspeed] = 
driftvel(course,groundspeed,heading,airspeed)

windfrom =
       84.717

windspeed =
       27.902

The wind is blowing from the right, 085 degrees at 28 knots.

Version History

Introduced before R2006a

See Also