Cloud Sensor vs PHD lost signal

[AlistairW]

Hello,

Been thinking about this for a while - my scope is on a pier and runs semi automatically over night capturing data. Rain is always a concern when unattended - so what i do currently is get SGP to send me a SMS message if PHD loses signal - which usually means a cloud has come across. This seems to work quite well, and i get a message to wake me in about 30 seconds.

I have been considering a cloud sensor but i am not sure this is going to give me any further benefit.

Of course the method above only takes in to account cloud that in the direction the scope is pointing and not any cloud that is directly overhead.

Is a cloud sensor without an observatory really worth it do you think ?

Alistair

[hughgilhespie]

Hi Alistair,

I think there are two issues - rain and cloud. Obviously for rain you either need to shut down automatically  - and quickly - but for cloud? Perhaps not. I have been thinking that a useful addition to the kit would be a sort of sky-quality scope, attached to the main telescope. This would have a field of view of say 4 by 4 degrees, aligned to the main scope and would use a cheap cmos camera and appropriate software to basically count the visible stars, platesolve, and then compare stars found with the number expected if the seeing is perfect. This at least would give a metric for atmospheric transparency. You could also make the software cleverer and start to compare say 1 degree square patches of sky to decide on the type of clouds about - all sorts of possibilities really.

Just my pennies worth. In the meantime, leaping out of bed seems to be the way to go.

Regards, Hugh