Vector Field function

Available with Image Server

The Vector Field function is used to composite and convert two rasters into a two-band raster that is of either data type Magnitude-Direction or data type U-V.

Notes

If the Input Data Type parameter is Magnitude-Direction, you also need to specify the Angular Reference System. parameter.

The U value is sometimes referred to as the zonal velocity or velocity along latitudinal lines. The V value is sometimes referred to as the meridional velocity or velocity along longitudinal lines.

Conversion between U-V and Magnitude-Direction

The two subsections below contain the formulas for the appropriate conversions. The variables are as follows:

• u = vector-U
• v = vector-V
• m = magnitude
• d = direction

Magnitude-Direction to U-V

u = m * cos (pi *d / 180)

v = m * sin (pi * d /180)

U-V to Magnitude-Direction

m = sqrt (u * u + v * v)

d = atan2 (v / u) * 180 / p

Parameters

Parameter	Description
Raster1	The first input raster. This will be either the U value or the magnitude.
Raster2	The second input raster. This will be either the V value or the direction.
Input Data Type	The type of vector field your inputs represent. Unknown—It is unknown whether the inputs represent U-V or Magnitude-Direction. U-V—Input data represents U and V components. Magnitude-Direction—Input data represents magnitude and direction.
Angular Reference System	Specifies how the direction component was measured. Geographic—0° points due north, and 90° points due east Arithmetic—0° points due east, and 90° points due north
Output Data Type	Specifies the type of vector field your output will represent. Magnitude-Direction—Output data represents magnitude and direction. U-V—Output data represents U and V components.