Cloud Sensor

Hi all

I have been approached by our local astronomy society to see if it is possible to display the amount of cloud cover.

It would appear that they monitor my site for local conditions but are still confronted with a long drive only to find there site clouded over.

A search of the web finds commercial sensors (v.expensive) or vague descriptions using a “thermocouple”?? device.

Does anyone have the plans or experience for such a cloud sensor that they would like to share? Could one be linked to W.D.?

Thanks in advance.


The least expensive one that I’ve seen is about $1000

I have been working on the possiblity of using an Infared Webcam, a strong infared emitter and some motion sensing webcam software as a way of making a poormans cloud cover detector, but I have no idea if it stands a chance of working. There are a number of “issues” that I’ve not yet worked out.

I have a webcam coming to play with.

It would not be able to determine the level the clouds are at, only if there were cloud cover. I was thinking of setting it up so that it did a cover, no cover count at say once a minute.

I’d be interested in knowing if anyone else has something that would be inexpensive to use.

how about a baloon tied to earth, with a mirror on the bottom of it, and then you shine a torch at it, then measure the refelected light back
just joking with ya!

How would you know where the Ballon was to shine the light at :laughing3:

Some of the New Zealand humor… :tongue8:

You hang a GPS unit connected to a transmitter onto the balloon and then track the balloon from the ground?

I’ve often wondered how to measure cloud height, but I’d have thought that the simplest way to show cloud cover during the day would be to mount a webcam pointing at the sky? At night perhaps you could arrange for a large light to shine skywards. Depending on how much cloud there was, you might see anything dim glow to a bright circle?

The local fun park has a couple of spotlights that they use on a regular basis, but unfortunately they move them round, so they’re not very good reference points for cloud cover.

I daresay astronomy buffs would Not Be Amused to have a bright light shining upwards near their observing site. In my own area, the local astronomy clubs have been working with the International Dark Sky Association to bring some rationale, with legislation where necessary, to have businesses and homeowners use less powerful lighting for signs and landscaping, and to not have so much light escaping into the sky serving no purpose (other than making astronomy more challenging and having all of us miss more of the night sky above us.

Edd, I presume your astronomy club knows about the “Clear Sky Clock” that is available here - that at least provides a forecast for cloud cover? Makes a nice application to put on your site, too.

NZ is one of the best places in the world for astronomy because of our clear skies (you can see for 100 miles most days no problem) and very little light pollution (pop. only 3.5 million), away from the cities (there are only 5)

I’m jealous… sitting here in the fastest growing county in the United States… in a 100+ year old house in a small town of just over 500 people tucked in hard against the foothills of the Blue Ridge Mountains… and having developments encroaching on all sides, politicians in the pockets of developers, farmland being paved over at an astonishing rate… very sad

Around here it might be the FAA that would be giving you problems. We have a upper level flight path that is near the house. Don’t ever hear them, but you can see them during the day and night.

Thats why I was thinking about using an infrared webcam and emitter. It would have to be pretty strong to reach high enough to hit upper clouds, but pilots would not have a problem with. We don’t have any Infared observatories around here (That I know of).

I can see the conspiracy UFO reports when someone finds a bright Infrared beam pointing straight up in the air every night though…

I think you’d be asking for a visit by the black helicopters if you tried the emitter idea on a scale that might work. Although if you ever watch those police chase shows you might get the idea to be able to market it as a way to escape those FLIR systems they use to nab the bad boys :smiley:

Found something new I didn’t see before…

Only $599

Group Purchase… to make it lower…


OR… maybe we could make one…

Worth a try, there are 40mm peltiers on ebay for $6.99 but you’ll need a sensitive meter.

I’m interested…would like to know what the group price is, and, can it be integrated with WD?
Did you find any sites using this??

Actually, I haven’t looked into it yet. I would imagine it might be easy to setup a group purchase for something like that.

I think I want to play with the possibility of making one first though. The peltiers are realitively inexpensive and sounds like a fun project. Get to do some electronics too.

As for interfacing it, I would think that would not be too hard.

if its a voltage to be read, then a labjack could work, i.e wd interfaces to a labjack, or a dallas 1 wire ADC

$600 bucks and you have to mount it with cable ties 8O

From the "Cloud Sensor User

Here’s the real thing These guys have some really neat (and expensive) stuff like ultrasonic wind sensors used in extreme conditions like snow measuring stations in the mountains.

Doesn’t a solar sensor imply the amount of cloud coverage?