I have a set of current data that is given as a series of 3 dimensional vectors (X,Y,Z). With X being the East-West flow, Y being the North-South flow, and Z being the vertical flow.
In the past I have been able to ignore the z flow, so calculating the current speed and direction has been relatively easy.
Speed= sqrt(x^2 + y^2)
Direction= arctan(y/x)
So if
x= -0.017112
y= -0.17241
Then my Speed should be 0.173 and my Direction should be 84 degrees.
But now I need to add in the z axis, and I'm not sure how to do this.
Speed is easy- Speed= sqrt(x^2 + y^2 + z^2). But I'm not sure how to get the same kind of directional data.
So for instance, if
x= 0.29
y=-0.095
z=1.392
What would be my speed and direction?
Best Answer
If you are interested in compass heading, you can ignore $z$ as you have been doing. You could add in elevation if you want, using $\arctan \frac z{\sqrt{x^2+y^2}}$. There are other formats for three dimensional direction, like direction cosines. Your equation for speed is correct.