Live Stacking in AstroDMx Capture

Nicola is working on the implementation of live stacking in AstroDMx Capture. Live stacking is a process favoured by astronomers using EAA (Electronically Assisted Astronomy). The imager can watch the image build on the preview screen and watch the Signal/Noise ratio increase as each new image is captured and added to the stack. Frequently relatively short exposures are used. In our experiments we have combined regular long, guided exposures (typically 5 minute RAW FITS files) with live stacking.

The implementation is not yet complete, but works in all the essentials and enables us to make this demonstration of the process. Thirty four RAW 5 minute exposures were captured of NGC700 through A William Optics 81mm APO refractor with an Altair Quadband filter and an Altair Hypercam 533C OSC 14 bit CMOS camera. The live stacking shown here is with uncalibrated frames, but of course, frame calibration in live stacking will be implemented as will image rejection.

For this experiment we used the camera simulator that Nicola has built into AstroDMx Capture. It is selected from the camera list in the usual way but uses previously captured RAW FITs files. If a real camera is selected, then the live stacking occurs on the captured frames as they are captured. This will be the next experiment. 

The signal to noise ratio increases as the square root of the number of frames stacked

Increase in Signal to Noise as a function of the number of frames stacked

Click on the animation to get a closer view

Live stacking results speeded up 200 times.

Steve Wainwright and Nicola Mackin