The common velocity axis definition in channel maps is that velocities coming towards us (blueshifted) are denoted with a '+' sign, and vice versa. This was the case until 38046c12d6d51abc00e31860d3a56d3c24cb0ae7, in which we fixed the doppler shift sign for some benchmarks (and thus flipped the frequency discretization of the images). The frequency information stored in the images is correct, but I forgot to correct the sign of the velocity in the resulting channel maps (see e.g. plot.py::image_mpl).
For fixing this, I will need to check which plotting functions include velocities. Afterwards, I'll add another warning to the documentation, stating the exact direction of velocity in the synthetic image channel maps.
The common velocity axis definition in channel maps is that velocities coming towards us (blueshifted) are denoted with a '+' sign, and vice versa. This was the case until 38046c12d6d51abc00e31860d3a56d3c24cb0ae7, in which we fixed the doppler shift sign for some benchmarks (and thus flipped the frequency discretization of the images). The frequency information stored in the images is correct, but I forgot to correct the sign of the velocity in the resulting channel maps (see e.g.
plot.py::image_mpl).For fixing this, I will need to check which plotting functions include velocities. Afterwards, I'll add another warning to the documentation, stating the exact direction of velocity in the synthetic image channel maps.