Processing question when using downloaded data that has already been calibrated

Miguel Morales

I am using calibrated data downloaded from Telescope Live am trying to process them in the order as described in the videos about Local Normalization.

1. Cosmetic Correction

2. Registration

3. Local Normalization

4. Image Integration

When performing Image Integration there are certain warnings that come up stating that the PSF and Noise calculations are being performed with non-raw data and that the results may not be accurate.

I assume that the reason for these warnings is that the entries needed in the fits header are missing due to the calibration not being done in PI

If the issue is actually that PI didn't calibrate the subs, is there a process that will add the required fits header entries... PSFFLX00, PSFMFP00, PSFNST00 and such, before doing Cosmetic Correction?

Thanks,

Miguel   8-)

BlockHead

This is an OK scenario.

In WBPP measurements are made immediately after the images are calibrated (and cosmetically corrected). However, WBPP *knows* it looking at already calibrated data that has not yet been measured. In fact WBPP doesn't even want to assume that other operations didn't happen- so it gives you a warning. 

You want to measure images immediately after calibration- and this is the data you are getting from TelescopeLive. So it gives you the warning AND it makes the measurements. 

SubFrameSelector is making the measurements. But you will get the same answer if you manually do it first..or if you let it happen in WBPP (with the warning being shown to you).

-the Blockhead

Miguel Morales

I am doing all this manually. I will eventually use WBPP, but I'm doing it manually first, trying to understand everything that needs to be done and especially why these things need to be done. For now I am finishing the processing at DBE. Doing thing just one bite at a time.

So, if I read your reply correctly, all the calculations and fits entries will be added to the files if I use SubFrameSelector right off the bat, and I will not get any warning when doing ImageIntegration. Correct?

You know Adam, you have an excellent sight here with lots of information that probably can't be found anywhere else. I just want to understand everything about processing that I can learn.

Thank you for all that you are doing to advance astrophotography.

Miguel   8-)

BlockHead

Correct. SubFrameSelector will do the measurements to the files and insert the information in the headers.

-the Blockhead