pyart.graph.common.radar_coords_to_cart

pyart.graph.common.radar_coords_to_cart(rng, az, ele, debug=False)

Calculate Cartesian coordinate from radar coordinates

Parameters :

rng : array

Distances to the center of the radar gates (bins) in kilometers.

az : array

Azimuth angle of the radar in degrees.

ele : array

Elevation angle of the radar in degrees.

Returns :

x, y, z : array

Cartesian coordinates in meters from the radar.

Notes

The calculation for Cartesian coordinate is adapted from equations 2.28(b) and 2.28(c) of Doviak and Zrnic [R1] assuming a standard atmosphere (4/3 Earth’s radius model).

\[z = \sqrt{r^2+R^2+r*R*sin(\theta_e)} - R\]\[s = R * arcsin(\frac{r*cos(\theta_e)}{R+z})\]\[x = s * sin(\theta_a)\]\[y = s * cos(\theta_a)\]

Where r is the distance from the radar to the center of the gate, \(\theta_a\) is the azimuth angle, \(\theta_e\) is the elevation angle, s is the arc length, and R is the effective radius of the earth, taken to be 4/3 the mean radius of earth (6371 km).

References

[R1]	(1, 2) Doviak and Zrnic, Doppler Radar and Weather Observations, Second Edition, 1993, p. 21.