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View Full Version : Three views of the International Space Station (ISS)



iceman
2008-Jan-29, 11:28 PM
Hi all

After a long break, interrupted due to changing jobs, new laptops, processing planetary and deep-space images - I finally got around to finish processing the two ISS images captured on the 26th and 28th of December 2007.

They were two spectacular passes, magnitude -2.4, passing about 70 overhead - though I could only capture them for about 40-50 seconds each, because of trees blocking the horizons.

I put my 12" newt on the dob base (not on the EQ mount), and aligned the finderscope with a star. I tracked the ISS manually by peering through the finderscope and moving the tube, trying to keep the fast moving bright dot centered on the crosshairs while my DMK21AU04 (in a 2x barlow) was recording at 60fps. Exposure used was 1/1200s and gain was almost maximum. Out of about 2500 frames captures, less than 100 had the ISS on them, and not all of those were sharp. I need to get a better hit rate!

It was an adrenalin rush, trying to get everything working for such a short period of time. On both occassions I forgot to press record in IC-Capture until about 5 seconds had passed! doh! And at the same time I had my Canon 350D and 17-70mm Sigma lens tracking on my EQ mount, pointed at the sky - and I had to remember to press the shutter remote to start the 2 minute exposure for the widefield view. Unfortunately I didn't have time to focus the lens accurately so the stars are blobby.

After all of that, i'm very pleased with the results though.
Thanks to Ralf Vandebergh for helping me to identify the structures.

The first image is from the 26th December, and the animated gif of the best frames for that session can be seen here:
ISS Animated Gif - 26th December 2007 (http://www.iceinspace.com.au/downloads/20071226-iss.gif)

The first image is from the 28th December, and the animated gif of the best frames for that session can be seen here:
ISS Animated Gif - 28th December 2007 (http://www.iceinspace.com.au/downloads/20071228-iss.gif)

The third image is the widefield view from the 26th.

Thanks for looking, comments welcome.

KaiYeves
2008-Jan-30, 12:11 AM
Sweet!

JAICOA
2008-Jan-30, 12:42 AM
Mike you did it again, Congrats on a great capture of ISS. Very sharp lots of structures easily ID. Welldone and Clear Skies

RickJ
2008-Jan-30, 12:43 AM
Very nice. I tried it once, failed miserably and haven't tried again. Well done!

Rick

winensky
2008-Jan-30, 01:47 PM
Mike,

You take some marvelous images of this station.Thanks for sharing

Kind regards
Matt

smasraum
2008-Jan-30, 05:51 PM
Outstanding!

iceman
2008-Jan-30, 10:07 PM
Thanks for your comments, guys.

I've only tried this 4 times - the first time I got an overexposed blob, the second time I got a whole avi of black frames with not a single hit recorded, and the third and fourth times are the results above.
It's essential to get the finderscope as accurately aligned as possible, get the focus spot on, and make a rough guess at the exposure. I usually put the 12" newt on my EQ mount to get focus right (so the star doesn't move) and rough adjustment on the finderscope, then move it to the dob base to align the finderscope again. I've found that looking through the finderscope even on a slightly different angle can mean hitting or missing the ISS in the FOV.

I guess at the exposure, starting at around 1/1200s for a bright overhead pass. I'm guessing it would need to be a bit less for dimmer passes.

For processing, I go through the avi in virtual dub, deleting the blank or blurry frames. When all that's left is frames with bits of the ISS in them, I save them as bitmaps. I then use ninox/ppmcentre to centre the ISS in the frame and crop the frame to something like 400x400.

I then hand-select the sharpest, best frames and layer (stack) them in photoshop, then save as tiff, take into registax for slight wavelet sharpening.

For the second shot above, I was lucky enough to capture a few frames where the ISS went behind a tree - this reduced the exposure and the overexposed areas (eg: the radiator on the right) came out at about the right exposure. So I processed them independantly, and used a layer mask to combine it with the overexposed one.

I look forward to trying again in a few days with another bright overhead pass - but the weather doesn't look good! :(

NGCHunter
2008-Feb-04, 09:15 PM
Fantastic shot, amazing detail, especially for hand tracking.