Sunday, October 30, 2022

checked the angle

Been a while... reopened the Vulpecula double stars project folder. I've been thinkin' about this for a few days now. I should get 'er done, complete the data reduction, and write the paper, before I run out of time.

I was ready to push my 37 images into an astrometric tool to measure the angle and the scale and was pleasantly surprised. 

I found that I had already done this step. Totally forgot! [ed: Yep, did it back in Sep 2020.]

OK. So that meant I got to move on, do a cross-check in another tool. Remoted into John Max, located the drift images from the Thursday and Friday nights, and analysed them with REDUC.

The data quality of this exercise is very low. I could only find one drift image, in a JPEG format no less, for each evening. Did I not take more? I should have...

I recalled the camera moved or rotated during the campaign which meant that more thorough drift analysis would be good. I made some notes, for the future, to get more drift images each time (a dozen or so), and to take them at the end of the session as well as at the beginning. Comparing the angle at the start and finish of a session would be telling. 

Still, thank goodness for the results for each individual image. It means I have an internal check, a self-calibration as it were.

My drift images do match up happily with the first images of each night! So that's a good albeit weak cross-check. It is obvious on night two that camera moved more than once...

Tracked down the RecToPol app. I'll use it for the scaling checks. Hopefully for all the images I'll be able to corroborate against the results from the astrometric tests.

Felt good to make a bit of progress here.

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