Installing a remote Observatory
Its been quite a while seen my last posting, although I have
not been active here, I been very active installing and setting up a new remote
system inside my observatory.
I will explain below the reasons why building this remote
setup and how I achieve it.
But first, why building a remote /automation observatory, my
current observatory is semi-automatic, not fully and not remote, meaning I need
to get up in the middle of the night or early in the morning when the sequence is
complete to switch off all the equipment.
Reason
Simply a automate telescope is a telescope system that can
operate autonomously. It is principally a system used for imaging whether this
is for capture of data for images of objects or scientific use. This could be
as simple as something at the backyard or a system on the other side of the
world. Robotic systems are useful because they allow you to capture data
automatically. You can be doing something else during unsociable hours like
sleeping! Systems such as this also allow you to capture data in more favorable
locations for seeing, darkness and objects.
Necessity
The basic components for an automate system are just a
telescope system that can be controlled by computer. automated does not
necessarily mean ‘Remote System’. It is just a system that can operate manually
initially, programed to run on its own on-side. For more advanced systems that
are left on its own, then you also need secondary equipment that can control
power, monitor the weather and react when conditions deemed as unsuitable or unsafe
are met. Typically, this also includes an observatory whose roof is motorized,
or a dome that will closed and open motorized, For remotely accessed systems a
good internet connection is also needed.
Choosing the components
Choosing components for a automate system is not that
simple, and you would need to inform youself. What will work depends on what
you want to achieve. If you are going to remain close to your system and will
turn it on / off etc manually less thought is needed. There are products that
suggest a simple route to full unattended operation using the wifi to
communicate at a short distance like the Primaluce Eagle. However, these do not
offer the full connectivity or power management needed for true remote
operation but do allocate attended operation. They simply replace your PC.
The Automated Observatory
For true remote operation you need an observatory with a
motorised roof (a simple Roll Off Roof type or Dome) but this needs to be
controllable. Motorising a roof is simple and no different to any other system
that uses a motor to open and close something like a garage doors a common
examples. Ideally the roof system should be computer controlled as this will
allow integration with other Astronomy software. If using a dome this is totally
different, the dome rotates, so for example while a roof top moves horizontal
from wall ‘A’ to wall ‘B’ (open and close the roof), the Dome is a Shutter
window open and close from ‘A’ to ‘B’, but the dome top rotates, second level of control is needed as not only
must you open & close the shutter of the dome, this must track with the
telescope. This also requires your telescope to be installed correctly, and the
slave data must be calculated.
The Automated Observatory – Dome Slave
Domes Telescopes on a fork mount with an equatorial wedge or
a normal EQ Mount like I have, will need to be offset because the center of the
telescope axis needs to be in the middle of the dome, not the pier. Get this
wrong and the opening of the dome will not remain synchronized with the mount
when both are moving. An Alt-Azimuth mount can be placed centrally as its
rotational center is the same as the center of the dome. Dome automation
requires accurate placement of the telescope and then configuration of the dome
drive system to keep the dome slit in line with the telescope axis. Dome
control software then synchronizes telescope and dome rotation.
Below showing the Rotation Driver that control and synchronize with the telescope movement.
The Automated Observatory – Roof
With a computer-controlled observatory, other functionality
becomes possible. - If, when in use, your telescope protrudes above the roof
line as it is imaging, once finish it must be parked before the roof can be
closed. This is possible with a computerized roof and it also does not
necessarily rely on a PC, you can park manually the telescope and close the
roof manually.
Domes do not have this problem as the telescope is always
within the ‘roof’. - With a system such as a Talon Roof controller or Dragonfly
/ AAG Cloudwatcher from Lunatico(this is what I have) , this will close the
roof after the mount is parked when an unsafe condition is met. It can do this
autonomously as it is only reliant on seeing a contact closure relay activate.
It knows the mount is parked because of small magnetic sensors that are placed
on the mount axis or at the roof on each end of the roof/ walls. As this system
is computerized and has an ASCOM driver, it can also be told to close by the
capture software.
Full System Control
First you will need to plan the type of relays system you need.
The next level of control is to have full remote control of
power and automate responses to events. Control of power and the ability to
turn things on and off remotely is important.
- 1. You could leave everything turned on. However that won’t do a dew heater much good or a camera.
- 2. A PC might eventually crash as operating systems are not designed for 24/7 365 operation.
- 3. Also, in the event of a power cut, things usually default to an off state so if you don’t have a way to turn components on and off, your sunk!
However, you will need to power the PC, as you cannot leave it all day’s weeks on, so if you use remote desktop, remote file access, or other server software, you may leave your computer on at home or work when you leave the house. This uses more power. Instead, you could remotely power on your PC whenever you need to use it. This takes advantage of Wake-on-LAN. In spite of its name, it’s possible to set up Wake-on-LAN so that you can send “magic packets” that will wake a computer up over the Internet.
Full System Control More advanced relay based systems also allow sensing using a contact closure input and conditional logic. This means they can react to external events. Such events might be loss of mains power, temperature, unsafe weather conditions or even a security event. A modern network enabled relay allows you to access it over the internet directly. You don’t need a computer, even a mobile phone can be used. Opposite is an example of an Astronomy optimised relay, called the Dragonfly, but really any network enabled relay can be used.
Plan
Dragonfly Diagram to connect the relays
Safety
With an unattended, remote system, two criteria must be met. The first is that everything must work! That sounds obvious but if your system is not local and you ‘assume’ it is all working you might be in for a nasty surprise. The second is keeping your system safe from possible damage. This is likely to be caused by either weather or loss of power. There is however the question of how to protect the optics as you won’t be around to remove the cap! A solution for this is a motorized cover, for example a Gemini Snap-Cap. This also incorporates a flat field so calibrations files can be made remotely. True that having a Dome will keep the dust always, but if the location of the observatory is nearby a construction, or sandy grounds, then dusts will crip in.
Safety Power (Back Up)
Some overseas countries are prone to power cuts. This may
because of unreliable supply or working practice. In Spain where I have my observatory
for instance, utilities companies will cut power without notice. For reasons
such as this, both your system and the observatory roof should be connected to
a UPS (Uninterruptable Power Supply), which is basically an inline battery.
These come in different sizes but one that offers about 30 minutes of life
after a power cut is normally sufficient to get everything shut down safely
before the battery goes flat. A simple relay that closes when mains power is
lost can notify your system of the problem and let it begin a controlled shut
down. If using a Roof controlled by Talon, this will sense a loss of power (and
is also on a UPS) and park the mount / close the roof.
Safety - Weather
AAG Cloudwatcher weather data on the computer
Software to control the entire systems (cameras, filter
wheel, mount, guiding exposure , targeting etc) Applications can also capture
mosaics and the most sophisticated can also ‘Re-Task’ the whole schedule based
on information received. Therefore if in the middle of a session, news about a
new Supernova was released, the schedule could be interrupted and the scope
would retarget on the new object. Some common examples of Scheduling Software
are; SGP (Sequence Generator Pro) like I have currently, but for more sophisticated
software go for Voyager.
Access – Remote Control
So you have all the equipment and the software but how do
you use it remotely? What is needed is something called a remote desktop. This
allows you to create a virtual desktop on a local PC (or tablet), giving you
the same control as if you are in front of the remote PC. Tablets are not ideal
because touchscreens can’t really replace all the functionality of a mouse. The
simplest way to remote access is to use the remote desktop functionality built
into Windows. However this is really intended to be used on an internal network
and as such its not ideal for internet based control. Specific, internet
compatible remote desktop software is now freely available.
A common choice is Teamviewer ( www.teamviewer.com ) and
another is AnyDesk ( www.anydesk.com ). These are free for private use and very
easy to setup. They work by connecting the two computers through a central
server. One advantage of this is that because the software dials in to a known
location, it can be used with Internet Services that use DHCP. Another popular
remote control application is Radmin (https://www.radmin.com/). This is a
direct peer to peer system which allow it to have less latency. However you
really need a fixed (static) IP address at the remote system location.
Personally I use both so as to provide a means of back up.
Access – PC Monito
In addition to having remote access to your PC you might
also want to consider the way your ‘remote’ PC screen is displayed locally. A
PC needs to have a monitor plugged into it in order to load a display driver.
You can leave the monitor turned off but it must be connected or you will see
nothing. The resolution of that monitor is what you will be able to use
remotely. An alternative to leaving a monitor connected is to use a display
emulator. These simply plug into the PC. Not only do these simplify your
install but they can also be hi-resolution.
DragonFly Manual :http://lunaticoastro.com/dragonfly/DragonflyUsersManual.pdf
