How to support a light roof for a shelter

[ss]

Picture from link.

I have a 6 foot high fence and the space between the 2 posts is 6 feet, I would like to create a light roof probably using clear corrugated perspex stuff. It would be easy to put in another 2 posts but this would block the exit if I need to get stuff in/out of my rear garden, so looking at how I could provide ample support from the existing 2 posts that are part of the fence. Any ideas on how I could support this? This area does get blasted when there are high winds so does need to be quite robust.

[Jabba]

ss scribbled...

You'd need to put a bar between the uprights at the top and triangulate the supports from the uprights to the roof or add supports at the front of the roof. Probably still blow away in a high wind.

[harryagain]

There can be no such thing as a light roof anywhere it snows. If you examine the manufacturers details for your roofing medium, it will give suggestions for minimum support. This will be your starting point.

[The Medway Handyman]

How about one of these, fixed to a horizontal board?

[ss]

That could be the answer Medway.