MATLAB
```[Vx Vy] = VTP2Vxy(Vtp,upTP,upSpec)
[Vx Vy] = VTP2Vxy(G,[Atm],upSpec)```

Rotates velocity vector from target T/P coordinates, or some other coordinate frame, into the desired coordinate frame. Rotation is based on the angle between the projection of the zenith direction onto the target plane, i.e. the plane transverse to the propagation direction, in target T/P coordinates vs. the user-specified zenith projection.

 Parameters Description Vtp [vector] Velocity vector in target T/P coordinates [V_TT V_TP] of size Nx2 (m/s). upTP [vector] Projection of the "up" direction onto the target plane in target T/P coordinates of size 1x2. upSpec [vector] Desired projection of the "up" direction
 Return Values Description Vx [vector] Component of transverse velocity in the x-direction (m/s) Vy [vector] Component of transverse velocity in the y-direction (m/s)

>> G = GeomStruct('simple',10,12000,50000,0,250,0,90);

>> [K,rhoP,rhoT,upECF] = TargCoordVec(G)

>> S = EngagementStruct(G);

>> [Vx Vy] = VTP2Vxy([S.V_PTT S.V_PTP],upECF*[rhoT' rhoP'],[0 1])

• Compute the platform velocity in the alternate coordinate frame where Vx represents horizontal component and Vy represents vertical component