Sign in to follow this  
turner112

No low vis at night?

Recommended Posts

Sorry - this may have been covered but I have searched without any luck...

 

Tried setting visibility to 2 miles at night; I could still see every light out to the horizon.

 

Any thoughts?

 

thx

Andrew

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

Can you provide a screenshot? Are you using any environment add-on (e.g. RTH) or tweak?

Share this post


Link to post
Share on other sites

Can you provide a screenshot? Are you using any environment add-on (e.g. RTH) or tweak?

I can  - I'll have to do that tonite. However, just imagine a screenshot, at night, with unlimited visibility... that's what it looks like!

 

No addons.

Share this post


Link to post
Share on other sites

I can confirm the finding - to a certain extent.

 

It seems that most streetlights have a greater visibility through haze than runway lights. Not unlimited, but much better. I will send a bug report if I can find the time...

 

Jan

 

Share this post


Link to post
Share on other sites

It seems the vis will only drop if you add clouds.  With no clouds but low vis I see unlimited vis.

Share this post


Link to post
Share on other sites

I can  - I'll have to do that tonite. However, just imagine a screenshot, at night, with unlimited visibility... that's what it looks like!

 

It seems the vis will only drop if you add clouds.  With no clouds but low vis I see unlimited vis.

 

Ok, I have an hypothesis.

 

Basically, in X-Plane the visibility you set in the weather screen, is limited to the altitude below the first cloud layer. This is true EVEN if there are no clouds. What is important is the altitude setting of the first cloud layer (even if it says "clear").

 

So, as soon as you climb over the altitude of the first cloud layer (even with no clouds), the visibility returns to max (unrealistically).

 

If the issue you're having is the one I just described, there are two ways to work around it:

 

1) increase the altitude of the first cloud layer;

 

or

 

2) set a "stratus" in the first cloud layer, to simulate a haze/fog ground bank.

  • Upvote 2

Share this post


Link to post
Share on other sites

This is correct, Murmur, and even to some extent realistic. Let´s say there is fog with an RVR of 200 meters. This is pretty bad. But sometimes those cloud layers are only like 100 meters thick, so you can readily see the runway and all airport lights as you fly overhead the airport. Only when you do the approach, it´s impossible to see the lights at a distance,because you try to see through the foglayer at a very oblique angle.

 

The problem here is a bit different, though. The effect of seeing streetlights "further" than runway lights is happening while well inside the haze/fog layer. A bug report has been sent to Laminar.

 

Jan

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this