plate solve failure

[cjacobson]

I have been trying to plate solve with AA7 . this has been a general failure. I can solve your "images" except the one of m57 which will not solve. I have entered a bunch of my fits images and they do not solve at all. I am careful about the ccd width and the focal lengths and still no success. I have entered the presumed RA and DEC from the star atlas for each object and no success. I have tried galaxies, open clusters and galaxies. I have tried flipping the images 180 degrees and reducing the bright galaxies so there are only stars. I have read your manual multiple times. I spend two nights under the stars trying this as well. I pointed my scope in the general direction of Altair, shot an image and tried to plate solve it several times on two different nights. NO SUCCESS! I have varied the search field of view without success.
The GOTO portion of the software works and will get close to the selected object but not right on it because I can not plate solve and hence can not synch.
Help please. This is totally frustrating.

If you are wondering > I can call up and object in the Star Atlas and its surrounding stars. The software will Identify some of the stars. and certainlyl the desired object will be presented. thus the GSC catalog is working.
there must be something fundamental that I am missing or do not understand.
thanks for any help. jacobson

[merlin66]

I had similar problems...
I received this sample script from one of the members (Iver):
Maybe this will help. This is a script I run after a goto , it takes an image, solves it, syncs the scope to the image and then centers the target.


raTar = Telescope.RA
deTar = Telescope.DEC
Camera.Binning(1)
Camera.Start(3)
Camera.Wait
ok = Image.FindCoordinates(raTar,deTar,5,4,106)
if not ok then Warning("Solve failed") : end
Telescope.SyncTo(Image.RA, Image.DEC)
pause (4)
Telescope.Goto(raTar,deTar)
Telescope.Wait
end

Once the parameters were set properly it works 100%. I use 4 x 4 degree "side" and the FOV matches my eFinder (106 arcmin)
From the manual:
Image.FindCoordinates (ra,de,stars,[side],[fovarcmin])
Finds the center plate via plate solving. It's possible to set the side
of the search zone in
degrees, default is 2°x2° and the field of view in arcminutes.

[fabdev]

Hi, which "horizontal field" did you set in the Find Coordinate window?

Before using plate solve for centering and syncing, you need to set and save the horizontal field in the Find Coordinates window, using an old image. If you like post an image to verify.

[cjacobson]

for the horizontal field I use the numbers derived by your computer. I input the sensor size in mm ie 23, and the focal length of the scope, mostly 900mnm=1.79degrees or 89arcmin. I have tried varying the numbers and have even tried your default 15. No help. I have changed the fov from its default to greater numbers-again no help.
I guess I could send you a couple of jpgs or place some raw fits in my dropbox. I'll have to remember how to do the latter. what ever is best to solve this issue. thanks to you and the other member. I will try his option in the meantime. cjacobson

[fabdev]

Hi, I think that only an image (JPEG is fine) could solve the mystery. If the images are oversampled and produce stars wider than 15 pixels, then the Service Pack 3 or 4 is required to correctly plate solve them.
The M57 image has a different format, its field is 12 arcminutes.

[cjacobson]

thanks; I took your advice using service pack 4 and added approximate coordinates of the field in question. They all solve! I was trying blind solving and some of my stars from the hyperstar were too fat!. thanks jacobson

[merlin66]

All's well that ends well.