For many years I've been using EQMOD to control my mount (currently an Orion HDX110 EQ G)
. Usually, at the start of session I would slew to a
reasonably bright star in the region that I'm interested in
hoping that it will be in the Field of View (FOV) . For the most
part it is. If not, Manual intervention is required.
I would have to:
- Look thru the finder scope and slew the mount till the star is
seen in the view finder.
- Next I would use the computer to center the star in the picture
- Finally I would sync the scope to the current location
Now the mount knows exactly where it's pointing. GoTo's after that
are usually very close. I I were to move to the other side of the
meridian, it's possible that I would have to go thru the above steps
again.
I had read about Plate Solving some time ago and tried it but didn't
have any luck getting it to work so I gave up.
I finally bit the bullet and made an attempt to try it again. This
time I had success with the help of a few acquaintances I met on one of
the forums.
Ok, so you may ask , what made me try it again? EQMOD is a
program that's been around for many years and works just fine but there
is very little incentive for the person supporting the application to
update it and incorporate some of the newer features of the EQ8 and
HDX110 mounts. So an ambitious and dedicated programmer and astro
enthusiast, Rob Morgan, decided to write a new application that
would mimic the main features of EQMOD and incorporate some new stuff.
In as little as a year and a half he has come up with a super package
that he calls Green Swamp Server (GSS) . You can get a copy by joining
the Yahoo group
(
https://groups.yahoo.com/neo/groups/GreenSwamp/info ) .
GSS handles the mapping of the sky differently than EQMOD and so doing
the initial goto's may be off and require the manual intervention steps
above. Rob is used to plate solving which overcomes this issue. I
was interested in using Rob's program so I was determined to get plate
solving to work for me. With help from Rob, Colm Brazel and
Lenny Shaffer we got it going.
So what is plate solving? It's a process controlled by a program that
compares and image taken by your equipment with known images of the
general area in an attempt to identify the actual coordinate at which
your telescope is pointing. This allows you to then synchronize you
equipment with the actual location in the sky. Once this is done
your goto's to an object should put the object near the center of
the FOV.
How to get started:
I'm using a WINDOWS 10 PC.
- Download a copy of AstroTortilla version 0.8 Alpha-1.
It's available from
https://sourceforge.net/projects/astrotortilla/files/pre-release/
in either 32 bit or 64 bit version is available
- When loading AstroTortilla load only the program
DO NOT load the CYGWIN
program nor the INDEX files.
Default all the other options during the install.
- Next install the Program that does the actual work
CYGWIN_ANSVR and the INDEX files used to do the solving from
http://adgsoftware.com/ansvr/ . Installation LINK and
instructions can be found here.
- After the program installs it will attempt to install the INDEX
files. You system may complain and block the PERL.EXE from
downloading them. Tell the system to allow this program thru the
firewall.
The space needed for the index files is considerable so it
will take a bit to download them
- Having installed the AstroTortilla and CYGWIN_ANSVR and all
the index files, you now need to change a setting in the
AstroTortilla program to point to the proper location for
CYGWIN_ANSVR.
Enter the following in the AT setup window line 8
C:\Users\{user id}\AppData\Local\cygwin_ansvr\bin\bash.exe
--login -c "%s" exactly placing your system login
ID in the proper place {user id}.
The process now will change to:
- Initially aim the scope in the direction of your
intended target. With guiding OFF
- Turn on AstroTortilla and do a plate solve and sync of that
part of the sky
- Slew to your intended target which should be near the centre
of the FOV. If need be center the object and sync the Scope to
the planetarium program.
- Turn on auto guiding if you are using it and commence with
the imaging session.
If your scope is remote ( in the back yard and you are
controlling it from inside your house) all this can be done without
going out to the telescope.
An Excellent tutorial on how to use AstroTortilla can be found
here
https://www.lightvortexastronomy.com/tutorial-setting-up-and-using-astrotortilla-for-plate-solving.html
. You will note that the instructions reference the CYGWIN
program. this has been replaced by the CYGWIN_ANSVR
If you have question or looking for some answers regarding AT you can
go to SourceForge at
https://sourceforge.net/p/astrotortilla/home/Home/
You can peruse the site. If you want to ask a question you have to join
SourceForge. No cost involved.
Take note that images taken with narrow band filters may be
difficult to solve as may images take at very high elevations.
