Introduction
ACP is an ASCOM compliant application that comes in various forms used to
script and control your telescope and camera. ACP does not directly
control your hardware, this is done through scripted control of Telescope
Drivers (ASCOM Helper objects) or MaxIm DL/CCD in the case of cameras.
ASCOM will run and display as a Windows Console (UI) or as a Web Server, the
latter offering the ability for access to the observatory from anywhere in the
world that internet access is available. Observatory automation and Remote
Observing is a vast subject area so here I will just cover what I do at HHO.
Where do you start?
Well the first thing you are going to need is the equipment. You will
need a GOTO telescope that can be controlled via an external source. (The
telescope will have to be correctly aligned) Next you will need a Camera
and, if you intend to guide the scope, an autoguider, second camera or dual CCD
primary camera (or an Starlight Xpress camera that offers self guiding.)
This is, effectively, your bare minimum. Yes you can have automated domes,
built in cloud sensors or weather sensors but that's all extraneous.
Ideally you will have a permanent observatory of some sort so that you can leave
your equipment permanently set up and protected from the elements when not in
use. Of course you will need a computer to control everything and almost
any computer will suffice (I use a 10 year old Athlon 1Ghz Pentium 4 predecessor
with 768mb RAM running Windows 2000.) If you are doing time critical
observing (such as NEO follow-up) then some means of accurately setting the PC
time and keeping it accurate to sub second accuracy will be needed. An
internet connection and appropriate time server software will suffice here.
Now BEFORE you try to automate the process you need to operate the various
components manually. Make sure you can enter an RA and DEC into the
software and that the telescope goes off and points to the right location.
Next make sure that when you trigger and image the correct filter is used, the
correct binning is set and the correct integration time is applied. Is the
camera kept at the right temperature? Next check that the autofocuser
works. I use FocusMax which can be used manually or can integrate into ACP.
Make sure it correctly controls the focuser. Next, take a picture then
platesolve it. Was it able to platesolve in a timely manner? Are
your telescope and camera settings set correctly in the ACP preferences panel?
Do you have the right catalogue installed?
Once you have proven that each element works reliably (ie more than once)
then it is time to start combining them. Do a point, image then platesolve.
Did the telescope point, take and image, platelsolve and determine if it was
pointed in at the right point of the sky? If so then it is time to move on
to add autofocus as well. Keep going until you have all elements working.
Now you are ready to try an actual observing plan.
The Observing Plan
ACP uses a very simple scripting language. Pick some targets (make sure
that they are above the observatory horizon) add them to the plan, set your plan
parameters then run it. If all is well then the telescope should very
quickly slew to the first targets co-ordinates, settle, take a pointing image,
platesolve it, correct the pointing then start imaging that target (or focus
where required)
A typical ACP Observing plan
(any line starting with a ';' is treated as a 'comment')
ACP Console?
The console has a simple UI. You can access everything you need (at
least whilst it is not executing a plan) and adjust a myriad of parameters to
suit your specific observatory and observing conditions. From the image
below you can see the telescope information on the left and the script
information on the right. Once the telescope and camera are connected (via
the Telescope and Camera menus) you can load your script. ACP Compiles it
then checks it. If the script is written incorrectly then ACP will
generate an error otherwise it will start observing.
Note that in my case, when I connect to the Camera, MaxIm DL/CCD
will open and ACP will communicate directly with MaxIm to have MaxIm control the
camera. Similarly, if I want to autofocus I will start Focus Max and let
ACP take control of it when it needs to. (ACP will determine when
autofocus is required based on image parameters passed back by MaxIm.
Alternatively you can script for ACP to automatically autofocus periodically or
you can choose to do it manually.
At the end of the observing run?
At the end of the observing run you have various options. For me, I
script for ACP to SHUTDOWN my observatory. This parks my telescope and
warms up the camera before auto disconnecting everything. Other
alternatives are to simply do nothing or to CHAIN to a new plan and start an
observing run with the new plan. As I stated, I shutdown so all that is
left for me to do it copy the observing runs images to my
Now we are looking at 'Real' science
So now I have outlined how amateurs, with backyard equipment, are capable of
making observations that provide data that scientists need. What's the
most obvious example? Well in 1978, when Dr Alan Harris started in the
asteroid game, only 157 asteroid lightcurves had been take, By the year
2000 that number had risen to 800 but in 2010, the number was well over 3600 and
that number continues to rise exponentially. A plot of asteroid size v's
period didn't reveal a great deal in the early days but now makes various
statements, the most obvious of which is commonly referred to as the spin
barrier, and it was the discovery of this barrier that resulted in the accepted
fact that most asteroids, particularly the small ones are gravitationally bound
rubble piles. So scientists are armed with another fact and with this
fact, new theories about asteroid formation and evolution are developed.
The next important discovery were the number of binary asteroids uncovered.
After nearly a decade, we have determined that approximately 25% of NEOs and
Inner Main Belt Asteroids are binaries. From this, we have uncovered the
theories related to the YORP effect and its subsidiary effect - BYORP. In
fact it has lead to new theories for the formation of binary systems as well as
asteroid pairs and the science will continue to evolve as we gather more and
more observational evidence - and we amateurs are at the leading edge.
Where are you?
