Brigthness, UV and Solar radiations are strange

Hello all. Last week I never had clouds on sky but I can’t understand why Brightness, UV Index and solar radiations has so many “holes”.
Is it a bug? Some problem with my Sky unit?

My Station ID is 2527.

All 3 graph are similar to this one:

just had a look and I see this almost each day. Shadow from a tree, house or something else coming over the sky in the morning hours ? Bird or other object (leaves) falling on top of the sky ?

I don’t think your sky is failing, rather something is dropping shadows … maybe go outside when it happens and observe your sky.

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Picture taken looking Nord. No building around, no trees.

Possible your antenna is casting a shadow?

indeed. it could be the antenna is casting shadows. Assuming the satellite dish points south, the antenna is to the east of the sky sensor, causing shadows in the morning. perhaps use a slightly longer mast for the sky unit, so it is above the antenna.

Yes, antenna is placed to East cardinal and dish point to south. I would expect antenna may be causing some shadows in the morning only… not in other time of the day. need to investigate further

sunny
June 29
indeed. it could be the antenna is casting shadows. Assuming the satellite dish points south, the antenna is to the east of the sky sensor, causing shadows in the morning. perhaps use a slightly longer mast for the sky unit, so it is above the antenna.

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At the moment no shadows on sky unit but still see poor w/m², UV etc etc

I think calibration is only applied with data of clear days. As yours experiences shadow every morning, it might mistakenly take those shadows as clouds and not apply calibration at all. (don’t know for sure, just based on assumptions)

@wfsupport Can you have a look at the raw data please

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Given the angle of the evening sun I can almost guarantee that what you are seeing is the result of shadows from the antenna.

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Seems strange. Now no shadows at all but:

We are at a similar latitude and I see similar values at the same times you do. All three of my SKY units show very similar values. I don’t see what the issue is.

So you’re seeing my same problem??

I hope @wfsupport will give us an explanation or solution.
I put SKY on the south side because nothing should be made any kind of shadow. Picture I took shows SKY in full sunlight but APP had low values. I would assume the problems are not shadows.

my suggestion is first to move the unit above the antenna. that will get rid of the holes you see. Support can’t do anything about that. After that auto-calibration will kick in and that will try to make your UV measurements more perfect. (try, as mine are still not good, but I do see occasionally some calibration taken place)

But it was at 18:44 according to the time in the screen shot. The sun is low in the sky so of course the value is low. Check the value at solar noon.

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See how brief the dips are? It’s likely large, optically thick clouds passing overhead. You’d be surprised how much they can bring down the UV on a bright summer day.