I saw an odd radius display very similair to this one April 5th this year, and another one with very faint 18 and 9 degree halos just recently.
Niceto see, that Thailand has its share of rare halos.Is there a scale to the photo? The best I can come up with is the right hand 18-deg column arc.Elmar
Actually the arc on the right and left is 18 degree plate arcs. 18 degree column arcs are above and below kind of on the sides.
Thanks, Michael, for correcting!Looked it up in Tape's "Angle x" book. The whole gamut of plate and column arcs is bewildering to say the least.Elmar