CometAlignment-selecting first image

TxAstro

Today, when I added files into CometAlignment, I saw the reference image I chose in WBPP was pinned as the first image in the list.  When I click "Load First Image", the reference image (11th image in the sequence), not the actual first image of the sequence was loaded.

Version 1.8.9-2 Build 1601

Is there a new way to select the first image of the sequence?

Thanks,

Xavier

BlockHead

Sorry...there is a disconnect for me. I do not know what the "Load First image" is.

Can you please create some screenshots. 

-the Blockhead

TxAstro

Made a mistake.  I meant the "Show First Image" button.  Screenshot is attached.

Xavier

BlockHead

The show first image is just that... the first chronological image in the list. 

The reason for this logic is that CometAlignment can be used to assume linear motion...so in general you can just click the first and last images. Doing this only measures the position. You can make any frame you want a reference frame regardless of position in the list. 

Again, opening a frame is just for purposes of measuring the position of the comet.

If what I just said does not make sense, please ask me again. 

-the Blockhead

TxAstro

Your description is how it has behaved before.  This time, clicking 'show first image' didn't display the first image in chronological order.  Rather, it displayed the reference frame which was at the top of this list.  That reference frame is the one I chose in WBPP.  I didn't choose it in CometAlignment.  This was the first time I have not seen the frames listed in chronological order.

As shown in your videos I clicked several images, including the first and last in chronological order, to mark the comet's position.  In the end the comet alignment seems to have worked fine.

Thanks.

Xavier

BlockHead

It is in chronological order. Please look again at your screen shot. Look at the observation time. 

We have to agree on this in order to continue.

-the Blockhead

TxAstro

I see something that I hadn't before.  I have been looking primarily at the date and time in the filename.  I used exiftool to construct the filename.  The time and date in the filename for image #1 is not the same as the observation time for that image.  It's different by several days in fact.  I will look at WBPP again.  My theory is that I entered the incorrect date and timefor the astrometric solution.  I did take images on 03/09, so that may be where I got the date.  I can't think of any other way the date and time could have gotten there.  It definitely didn't come from the CR2 file.

I will let you know if that is indeed the case.  I really hope it is.

Thanks,

Xavier

TxAstro

It looks like that is indeed the problem.  To be absolutely certain, I wanted to change the date and time of the image.  I updated the dates using FITS header, and I confirmed that they were changed.  They didn't carry over to the XISF attributes.  The BatchFITSKeywordEdit  was totally unresponsive and hanging, so I couldn't try using it.  I even tried to rerun ImageSolver using the correct date and time, but after it completed the date and time remained March 09, and the FITS keywords were back to March 9 as well.  I guess the only way to change the XISF attributes is to start from the CR2.  I'll just make sure to use the correct date the next time.

Thanks,

Xavier