Mar 28 2026 APP 2.0.0-beta40 will be released in 7 days.
It did take a long time to have the work finished on this and it will have a major performance boost of 30-50% over 2.0.0-beta39 from calibration to integration. We extensively optimized many critical parts of APP. All has been tested to guarantee correct optimizations. Drizzle and image resampling is much faster for instance, those modules have been completely rewritten. Much less memory usage. LNC 2.0 will be released which works much better and faster than LNC in it's current state. And more, all will be added to the release notes in the coming weeks...
Update on the 2.0.0 release & the full manual
We are getting close to the 2.0.0 stable release and the full manual. The manual will soon become available on the website and also in PDF format. Both versions will be identical and once released, will start to follow the APP release cycle and thus will stay up-to-date to the latest APP version.
Once 2.0.0 is released, the price for APP will increase. Owner's license holders will not need to pay an upgrade fee to use 2.0.0, neither do Renter's license holders.
When I evaluate my take from a night of imaging, the first thing I look at is Star Roundness. Generally, I delete subs below 0.70.
I thought I understood this as a measure of roundness, with 1.0 being a perfectly round star and fractions being oval to some degree.
However, for some time I have noticed that sometimes subs are graded by APP with Star Shape numbers greater than 1.0 I' need to understand this better before deleting any more data.
What is Star Shape exactly measuring, and what is the range of values?
Hi Jeff @jeffmorgan,
The star shape score is a combination of 2 things:
1) the average star size in the x and y-direction of the median star of the population, it is important to realise that this is a relative measure between your frames 😉 Registration of data with different telescopes/camera's will correct this for pixel scale difference after registration completes.
2) the roundness of the this median star in the population
Now, The star roundness will have a maximum of 1 for perfect round stars. But the size score can be more than 1 or much less...
The formula for star size is 3/(star size x-axis + star size y-axis). So if the average size of the star in both directions is 3 pixels. The star size score is 1. If the average star size in both directions is only 2 pixels. The star size score will be 1.5.
This star size score and star roundness score are simply multiplied, so it can be as high as the star size score for perfect round stars 😉 giving values of nearly 2 when you have under-sampled your stars (FWHM less than 2 pixels).
Hope this clarifies it 😉 All will be detailed in the forthcoming manual.
Mabula
