adam.util.aeqd_to_lonlat#

adam.util.aeqd_to_lonlat(x, y, lon_0, lat_0)[source]#

Convert azimuthal equidistant coordinates to longitude and latitude on the WGS84 ellipsoid.

This is a self-contained replacement for projecting radar gate positions with PROJ (+proj=aeqd +ellps=WGS84). ADAM feeds the resulting image to a neural network, so the geolocation has to be reproducible: a change in the projection library shifts every gate, which moves the inferred lake breeze front. Computing it here means the model input depends only on this repository. The result agrees with PROJ to well under a micron.

Parameters:

  • x (array-like) – Distance east of the projection centre in metres.

  • y (array-like) – Distance north of the projection centre in metres.

  • lon_0 (float) – The longitude of the projection centre in degrees.

  • lat_0 (float) – The latitude of the projection centre in degrees.

Returns:

  • lon (numpy.ndarray()) – The longitude of each point in degrees.

  • lat (numpy.ndarray()) – The latitude of each point in degrees.