Re: Multi-aperture sequence stops when star not found
Posted by karenacollins on Jul 11, 2013; 10:44pm
URL: http://astroimagej.170.s1.nabble.com/Multi-aperture-sequence-stops-when-star-not-found-tp55p56.html
URL: http://astroimagej.170.s1.nabble.com/Multi-aperture-sequence-stops-when-star-not-found-tp55p56.html
Hi David,
The way to handle this properly is to align the images first using a few bright stars using Process->'Align stack using apertures' in the menus above the image stack (this feature works similar to Multi-aperture). After you finish alignment, run Multi-aperture using the full set of stars you are interested in. When you place the apertures on the first image, make sure the the centroid feature is turned on as usual, BUT before you left-click to advance to the second image, turn the centroid function off (there is an icon above the image to do this - it looks like an offset circle
- make
sure it looks "un-depressed"). Then, left click to process the
rest of the images.
Since centroid will not run on the remaining images, you should not have the problem you reported, and the aperture will be in the correct location since you used centroid on the first image and all images are now aligned.
This way, you know the aperture stays in the location you want it to be, even if a star fades to much into the sky background to find a centroid.
If I change AIJ to allow the processing to continue, the aperture may have wandered off to a nearby star without you realizing it. The above procedure should solve your problem and prevent erroneous data.
Let me know if you still have problems.
The way to handle this properly is to align the images first using a few bright stars using Process->'Align stack using apertures' in the menus above the image stack (this feature works similar to Multi-aperture). After you finish alignment, run Multi-aperture using the full set of stars you are interested in. When you place the apertures on the first image, make sure the the centroid feature is turned on as usual, BUT before you left-click to advance to the second image, turn the centroid function off (there is an icon above the image to do this - it looks like an offset circle
- make
sure it looks "un-depressed"). Then, left click to process the
rest of the images. Since centroid will not run on the remaining images, you should not have the problem you reported, and the aperture will be in the correct location since you used centroid on the first image and all images are now aligned.
This way, you know the aperture stays in the location you want it to be, even if a star fades to much into the sky background to find a centroid.
If I change AIJ to allow the processing to continue, the aperture may have wandered off to a nearby star without you realizing it. The above procedure should solve your problem and prevent erroneous data.
Let me know if you still have problems.
KarenOn 7/11/2013 4:26 PM, David Emory [via AstroImageJ] wrote:
When using the multi-aperature photometry with a sequence of images, the processing stops on the images after the first image if all the stars cannot be found. When this happens, the only option is to stop.
As an example, on image one, I ID 100 stars, then right-click. The first image is processed, and I can left-click to advance to the next image. I then ID the first star, get all the apertures set and then left-click for all the remaining images.
The problem arises when a star is not found (it can find 99 out of 100). Processing stops at that time, and I cannot recovery anything. It would be good if there is a way for the program to put in an error code and go to the next star and continue the processing.
If you reply to this email, your message will be added to the discussion below:http://astroimagej.1065399.n5.nabble.com/Multi-aperture-sequence-stops-when-star-not-found-tp55.htmlTo start a new topic under AstroImageJ, email [hidden email]
To unsubscribe from AstroImageJ, click here.
NAML
| Free forum by Nabble | Edit this page |