Topic: Oh the Challenges of Recording Sunshine Duration

[EGR cooperative observer]

Hi Everyone -

One of the known limitations of sunshine duration sensors is not capturing the minutes shortly after sunrise and shortly before sunset.
Any ideas of an economical? way to have one camera pointing east and another west to record 1.5 hours after sunrise and 1.5 hours before sunset.

Perhaps I could use a PTZ camera and program it to point east in the morning and west in the afternoon.  I would record constantly for those 1.5 hours.

This would allow me (when I can't have a human observe every minute) to add at least a close estimate.

Thank you for your thoughts!

[mcrossley]

Sunshine hours requires a direct irradiation value of 120 W/m2, I doubt you will be getting that value close to sunrise/sunset.

[EGR cooperative observer]

Yeah, I've never agreed to the 120 standard.  A standard based on pre-historic Campbell Stokes.

The NWS, which I would concur with in this case, indicates that as long as a shadow is present, there is sun.  Their threshold is lower (closer to 85-90).

I agree on not getting that at sunrise / sunset.

[broadstairs]

The trouble with all the affordable solar sensors measure global radiation where the 120 w/mē does not apply. The ones which do measure direct radiation are way out of amateur price ranges.

Stuart

[davidmc36]

I am lucky enough to have acquired a Blake Larsen Sun Recorder at a sensible price.

A replacement will likely be out of my budget.