Pixinsight's New Spectrophotometric Color Calibration Process

[Juno16]

Hi AP’ers,

Just curious is anyone here has tried the new Pixinsight SpectrophotometricColorCalibration process and what are your thoughts?

I saw SPCC on the latest release (1.8.9-1 Ripley x64).

Pixinsight announcement:
https://pixinsight.com/forum/index.php? ... pcc.19599/

Pixinsight Reference Documentation:
https://pixinsight.com/doc/docs/SPCC/SPCC.html

The new SPCC process is based on the latest Gaia Data Release 3 (Gaia DR3), released on June 13, 2022.

According to Juan Conejero, Pixinsight Principal Developer, “This is the first massive, accurate spectrophotometric catalog in the history of astronomy, with unprecedented homogeneity and consistency thanks to the fact that it is based on measurements made from space, without the varying conditions of the atmosphere”.
“SPCC can outperform PCC (the PhotometricColorCalibration tool) by a 400% increase in precision“.

There are two different downloadable versions of the Gaja Data Release 3. A “small” version (not sure, but possibly 15-20 GB) and the full version (60GB).

I downloaded the full Gaja Data Release 3 version. I am currently storing the full version on a conventional (mechanical) internal 4TB drive and run Pixinsight from my 512GB nvme boot drive) and the process runs reasonably fast.
Luckily, I have a decent amount of storage on my pc at 8.5TB right now. My new 2 TB nvme boot drive (early Christmas present) is sitting on my table and it will bring me up to 10.5TB of total internal system storage.

The new SPCC process requires an astrometric solution. Otherwise, when you run the new process, you must run the ImageSolver script first, or the SPCC process will fail. Even though the fits header contains the RA and DEC values, the SPCC process requires an astrometric solution to function.

I noticed Astrometric Solution as a “default on” option in WBPP in the previous release. I had turned it off because of the time it takes and I didn’t think that I needed it.
@STEVE333 – You might have known what WBPP used Astrometric Solution for, but I had no idea. Seems like the PI crew must have inserted Astrometric Solution into the previous version of WBPP in readiness for the SPCC process to be released in PI version 1.8.9-1.

I have used SPCC a couple of times recently including my recent re-process of M1 posted a few days ago. Even though I get good color calibration results by just dragging the default ColorCalibration instance onto the image, I will use SPCC as my goto color calibration tool.

Here is what the finished process looks like.

Please share any experience and feelings that you have concerning the new Pixinsight SPCC process!

[Gmetric]

Very interesting, Jim. I downloaded it and installed it in PI recently but have not had a chance to use it. I think it's the closest thing yet to realistic and true-to-life colour calibrations. I love the idea of it and can't wait to give it a shot. Certainly takes out the guesswork! Thus far, whenever I have used WBPP it fails when running through astrometric solutions so I'll have to figure that out first, I guess.

[Juno16]

Very interesting, Jim. I downloaded it and installed it in PI recently but have not had a chance to use it. I think it's the closest thing yet to realistic and true-to-life colour calibrations. I love the idea of it and can't wait to give it a shot. Certainly takes out the guesswork! Thus far, whenever I have used WBPP it fails when running through astrometric solutions so I'll have to figure that out first, I guess.

Astrometric Solution in WBPP has failed for me too sometimes, and sometimes not. No biggie though. You can crop (if needed) and run Background Neutralization on the Masterlight, then run the ImageSolver script (Script, Image Analysis, ImageSolver). Click the Search button and enter the name of the target (M31, NGC 281, etc), choose the target name and drag and drop the New Instance (right triangle in the lower left corner) on the image. After that, just run the SPCC process. I recommend watching a video on YouTube and also reading the links in my original message. It seems as filter choice is very important!
Good luck G!

[STEVE333]

Thanks Jim for being the "tip of the spear" on testing out so many of these new processes and then sharing with us.

I hadn't been checking the "Astrometric Solution" box, but, only because I didn't think it was needed and it never complained.

Good luck with the new color calibration process.

Steve

[Juno16]

Thanks Jim for being the "tip of the spear" on testing out so many of these new processes and then sharing with us.

I hadn't been checking the "Astrometric Solution" box, but, only because I didn't think it was needed and it never complained.

Good luck with the new color calibration process.

Steve

I usually install the latest updates soon after I receive the announcement email. BUT, after recently getting burned by a WBPP Local Normalization update (long story), I ALWAYS very carefully read the update announcement before updating PI.

The new SpectrophotometricColorCalibration process just sounded too intriguing to not try out!

I used it in a recent repro and really liked the results.
viewtopic.php?p=225690#p225690

Also, now I realized why Astrometric Solution was added to WBPP!

Thanks Steve!