Cloud Sensor Project - Part 2

[Mike]

Right, last night i spotted a bug in the algorithm that was preventing it from detecting the clear/cloudy state.

I have also tidied things up a bit and made the blue a lot lighter. I am currently working on a version with a colour picker that will probably be up by tonight. The program will now keep a log text file in the same directory that logs each data reading as it comes in. This is in the format - DATE, TIME, SKY SENSOR, GROUND SENSOR, SKY STATE (Between 0 and 1 : 0=cloudy  1=clear). You can open the log file in a text editor and view all of the temperatures and sky states logged over time.

The updated version 1.1 is available here :-

WINDOWS:  http://www.amateur-astronomy.org/Filez/CloudClientWindows.zip
LINUX:        http://www.amateur-astronomy.org/Filez/CloudClientv1_1.linux.zip
MAC OSX:    http://www.amateur-astronomy.org/Filez/CloudClientv1_1.macosx.zip

Note that the sky state, i.e. Clear or Cloudy or anything inbetween, is an average of the whole sky and not just the sky above the sensor. i.e. if the sensor is showing 50/50 clear/cloud and you look up and it is clear it means there must be cloud lower down nearer the horizon. Also remember the further away from my location you are the less accurate it will be.

Please let me know if you have any problems or spot a bug. Thanks.

[Fay]

Mike, you are very clever inventing a cloud sensor, perhaps you will be more reliable than all the other forcasts!

[Mike]

Well it doesn't forecast clouds, just tells you the current sky state. It is a way to see if it is cloudy or not without having to go outside. Will be useful for imagers who fancy a nap, etc. or who are watching TV and want to know when it clears. It will eventually have alarms, etc.

[Mike]

Oops!! 

Sorry Windows users I posted a link to the old version 

Here is the latest version 1.1 ......

http://www.amateur-astronomy.org/Filez/CloudClientv1_1.windows.zip

[Mac]

Yup the blue is alot easier to read, and the data logging bit is working ok,
and it seems fairly accruate, its saying 50% between cloud and clear,

Just checked and its about right.
Mac.

Might leave this running all night and see what the temperature gets down to.

[Mike]

Yeah that's how I knew it was -6.75 last night.

I'm pretty pleased how well it is working. Whenever the trend changes between cloudy and clear I take a look outside and so far it has been spot on. It's interesting for it to be 50/50 and you look out, see it appears to be completely cloud, or completely clear, and yet when you pop outside and have a proper look another part of the sky is the exact opposite.

[MarkS]

Mike,

It's very "iffy" on my version of windoze XP. 

I got it to run once (clicking on CloudClient.exe directly from the zip) but every time I try it now I get an error dialog "Could not find the main class.  Program will exit" from the Java Virtual Machine Launcher - whether running direct from the zip or copying the files locally.

The one time it ran, it all worked perfectly.

Maybe I have a dodgy version of JVM.

Mark

[Mike]

Sounds like it to me. Try reinstalling Java. I downloaded it onto my laptop and it works fine. Mac has his running too. Let me know if you have any further problems.

[JohnP]

So Mike,

Out of interest (you probably said all this before but I can't remember) does your cloud sensor literally just decide how cloudy it is by the difference between the 2 temperature measurements? Also if I knew how to could I access your computer via the s/w you have provided & could you do the same to mine....? The cloud sensor seems to update realtime so the cloud level is always changing - do you have plans to plot a trend line or something... i.e. so I can see for the last 2hrs it's been 90% clear even though at the moment it is cloudy...

John

[Mike]

John,

Yes the two sensors are housed differently to ensure that one reads the ambient air temperature and the otehr is shielded and housed in such a way it onyl reads the 'black body radiation' from space. This will create a temperature difference when it is clear and will have an almost identical temperature when it is cloudy (as radiation is bounced back from the clouds to the top sensor).

Access would be possible I guess but no more or less thatn usual. There are no holes opened up if that is what you mean.

Yes I intend on creating a 24 hour cloud state graph so you can see the last 24 hours clear/cloudy state. From the change in trends the user can then establish their own alarms, etc. from that.

Anyone wanting their own cloud sensor made for them can then use it to set of alarms, control observatory roofs, interrupt imaging scripts, etc.

Once I get it to work this software will be uploaded to my website so people don't need to download the software at all they can just visit the page. The software is available now as a workaround as I can't yet get the webpage script to work properly. Anyone with their own cloud sensor can obviously use the software locally.

[JohnP]

Very impressive - Have you got plans to market it..? Seems like you have put an awful lot of work in & something that could be very useful to a remote imager.. i.e. one of those that sits indoors & controls everything... I could see this more as something people wanted to buy rather than looking at what the clouds are like in Orpington...

Access would be possible I guess but no more or less thatn usual. There are no holes opened up if that is what you mean.

No I was just wondering how secure it and why loads of porn has suddenly appeared on my laptop.... 

Very good work anyway - John

[Mike]

I do plan on marketing it as long as I can manufacture it in a small package, around the size of a box of Cooks Matches would be good. I would like to make a wireless version (and possibly also solar powered) too.

I think a price of around £100 is reasonable and a lot cheaper than the Boltwood unit at around £700.

[Mac]

Problem with Cloud sensor 

Having left the sensor program running  since 22:09 last night,
i just checked and found the temperatures at 10.06 & 6.31.
and that the display has frozen at 12:11!

[Mike]

The server is still ticking away. Have you restarted and if so is it the same?

[Mike]

Must be your end Mac. I've just fired up the client on my laptop and it is displaying the same temperature as the server is outputting.