This is an e-mail message from Neal Rasmussen (posted with his permission)

I am a tornado chaser for 20 years. About 4 years ago I was driving through a McDonald's drive thru. As it was just after a pretty good storm, I had mys polarized yellow tinted flip-up sunglasses on. Low and behold I almost dropped my cigarette into my lap. There off in the east was a double rainbow! Not the kind I've seen dozens of times where the second one is reveresed and much outside the primary, but this was immediatly INSIDE the primary!

Gaping with my mouth open and people behind me honking, I flipped my flip-ups up and the second inner one went away! I must have sat there for 2 minutes flipping my sunglasses. The colors were NOT reversed and it looked like one continuous double wide rainbow, with two complete sets of colors. I ruled out that the flip-ups where giving double vision as I looked at lights the next day, streetlights headlights, etc. and no doubles! Can this possibly be? Could a source of polarized light be at a different angle, perhaps the sun shining through a cirrus cloud or noctelucent (sp).

Hi, I am facinated by rainbows but am not smart enough to understand it all.
I do know that the most amazing one I have ever seen was when I was in a
small single engine aircraft above a layer of white clouds.  The cloud cover
was smooth and the sun made a shadow of my aircraft .  As I looked at the
shadow of the aircraft on the clouds I noticed it was encircled by a
circular rainbow. The rainbow followed until the cloud cover changed and then
disappeared.  Sincerly, Jim Spencer

I was always dreaming to be able to see the same view as you have seen (whenever  was on  an airplane).
What you have seen is a true rainbow. Circular rainbow can only be viewed from above the ground.
When we were on the ground, at least half of them were missing.
The viewing angle is about 42 degree.

Hi, yes you may use the letter any way you like.  If you do I wish you would
let me know so I can look at it.  The angle from where I was sitting in the
aircraft and the shadow was about 45 degrees as I remember it and I wonder if
the angle had been greater or less do you think I would still have seen a
rainbow or was I just fortunate that day to be at the right place at the
right time ??  Jim Spencer