Combine; Filter; Normalize; Fix Column Defect - Meade Autostar Software Manual

The program will go through all of the images an shift them so that they will be aligned on the select star.
After the the images have been aligned, a proof image will be created by averaging together all of the
images in your group and displaying the results. It may take a couple of interrations to get all the images
to line up if you are working in a crowded star field. The technique will work best if the alignment star is in
a relatively isolated portion of the image.

Combine

The Combine command is used to combine all of the images in the group into a single image. There are
several different combination methods available.
Sum adds all the images together.
Average averages all of the images together.
Median takes the middle value of all the images at each pixel location. This method will drop out cosmic
ray hits and other random noise from a group of images although the processing can be somewhat
lengthy.
Minimum takes the smallest pixel value of all the images at each pixel location.
Maximum takes the largest pixel value of all the images at each pixel location.

Filter

The Filter command allows you to apply any of the filter techniques found under Process to the entire
group of images. Filters available include:
Convolve
Median
Unsharp Mask
Fix Hot Pixels
Fix Cold Pixels

Normalize

The Normalize command processes all of the images in the group so that their mean value is 10,000
ADUs. This command is most commonly used to prescale sky or twilight flats before median combining
them to drop out stars, satellites and other transient effects.

Fix Column Defect

The Fix Column command, fixes bad columns in all the images of the group. If functions as described in
the Process section of this manual.

Photometry

The group Photometry command allows you to measure a large number of stars in group of images. It
makes variable star, extra-solar planet transit searches, asteroid rotation and comet study easy. In all of
these activities, you may have a large number of images of the same field of view taken at different times
where you wish to measure the same group of objects in each image.
When this command is selected the group photometry dialog will appear similar to the example shown
below. Additionally, the first image in your group will be displayed behind it. Select all the objects that you
wish to measure by drawing a box around them.
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Autostar IP