Stacking Multiple Nights Data Sets for Startools ( Mono 2600MM Camera and filters )

[Martin Dowd]

Long time user of DSS , first time user of ASTAP ( calibration ,alignment and stacking only ) Brilliant Stacker !!!!
Sucessfully stacked and aligned 1 night LRGB data set
Sucessfully stacked and aligned 1 nights Ha Oiii Sii data set
Startools requires individually stacked data sets per filter and aligned to each other prior loading into Startools Compose channels. Stacked data sets must have no color calibration or adjustment , no background calibration , no stretching , just raw clean linear stacked data sets. Refer Startools prerequisites ( Ivo Jager )

Please advise on best procedure to stack ( combine ) multiple nights data from the same filter , and for each filter and then align those multiple stacked data sets for loading into Startools Compose via individual channels.

Attached is my step by step procedure for stacking 1 nights data set and aligning between filter sets for loading into Startools Compose.

Thanks and await your advice and procedures

Martin

[han.k]

Hi Martin,

In principle you can combine the images of several nights in one go. That would be the normal preference. However if the sky background is different it could be better the stack each night separately (using sigma clip). Then combine the results of each night using "stack average". The reason is that if the background is different the outlier detection of the sigma clip doesn't work effective.

Note there is a stack method "Sigma clip, skip LRGB combine".
You can drop all files in the light tab. The should produce all stacked files in one go. The filter detection in tab "stack method" should be set correctly once. If you see the red, green,blue, grey icon in the light tab then the filter names are detected correctly.

18/ To save stacked image to your PC, go to File ( top left ) click on it and select “Save as FITS file”. Save
stacked image to your nominated location on PC. You can add a suffix to further identify the image
however image file name should end with the word “stacked”

Note that the stack is always saved. You can access them in tab "results"

Ensure you are using the latest stable version of ASTAP ( don’t use development version )

Note that the last development version (2023-09-18) introduces a significant improvement in processing speed

Han

[Martin Dowd]

Thanks Han,
ASTAP looks like a much more intuitive and intelligent stacker than DSS
A very simplistic procedure for multi night stacking
Thanks for your reply
Clear Skies
Martin