Parity with zea
Names and angles
Transducer frame: x along the array, y across it (elevation), +z into the medium, z = 0 at the middle of the array. Angles in radians; this page shows them in degrees.
| Name | Meaning |
|---|---|
polar_angles θ | Spherical polar angle of each transmit, from +z. 2D data stores it signed, positive toward +x. |
azimuth_angles φ | Spherical azimuth of each transmit, around z from +x. Zero in 2D. Not the ultrasound “azimuth” (lateral) direction. |
polar_limits | Polar angle atan(x / z) of the first and last column, seen from grid_apex. Equals θ when φ = 0. |
rlims | Radius of the first and last row, from grid_apex: zlims − grid_apex[2]. |
zlims | Depth of the first and last row, from the array (z = 0). |
grid_apex | The point (0, 0, −d) the polar grid fans out from. |
elevation_limits | 3D only: elevation angle atan(y / z). A 3D frustum is this page's sector extended in elevation; every name above keeps its meaning. |