30th Anniversary of the Voyager 1 Flyby of Jupiter |
30th Anniversary of the Voyager 1 Flyby of Jupiter |
Nov 19 2009, 04:13 PM
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#31
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Member Group: Members Posts: 903 Joined: 30-January 05 Member No.: 162 |
I really appreciate this thread as 30 years ago I totally missed the Voyager 1 Jupiter encounter. I had signed up for the Eclipse over Big Sky Country and was in Montana enjoying the Huntley Lodge and watching the last total solar eclipse visible from the continental US till 2017. The eclipse was grand and a lifetime memorable event, and it was just about the only thing that could have kept me from watching the Jupiter spectacular.
I was surprised shortly after the trip to note Time magazine had covered the flyby and the eclipse in the same issue. There were roughly 400 eclipse chasers in the Eclipse Bus Caravan (LOL) and we wound up watching from just west of Roundup, Montana. The trip organizers had access to weather satellite imagery (I have no idea how they did this in 1979) and managed to put the Eclipse Bus Caravan under a break in the clouds as the eclipse passed over us. We did have some high altitude haze, but it actually enhanced the view. To make up for missing the Voyager encounter I ordered every 35mm slide set I could find and bought a slide projector. Much more handy to have the enhanced pictures here at UMSF. Thanx! |
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Nov 20 2009, 02:36 AM
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#32
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Interplanetary Dumpster Diver Group: Admin Posts: 4404 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
Great work! If I might suggest something, flat fielding the images would get rid of the bright corners in the images.
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Nov 20 2009, 03:03 AM
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#33
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
What do you use for a Voyager flat field, Ted?
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Nov 20 2009, 03:34 AM
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#34
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Member Group: Members Posts: 207 Joined: 6-March 07 From: houston, texas Member No.: 1828 |
What do you use for a Voyager flat field, Ted? um actually not always. I use the standard calibration flat fields in ISIS and sometimes the corner flares persisted. The VGR vidicon usually but not always obeyed its own rules. In that case I just crop the corner. Image calibration is not always a 1-2-3 procedure! -------------------- Dr. Paul Schenk, Lunar and Planetary Institute, Houston TX
http://stereomoons.blogspot.com; http://www.youtube.com/galsat400; http://www.lpi.usra.edu/science/schenk/ |
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Nov 20 2009, 04:55 AM
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#35
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Member Group: Members Posts: 890 Joined: 18-November 08 Member No.: 4489 |
QUOTE I really appreciate this thread as 30 years ago I totally missed the Voyager 1 Jupiter encounter. i did not quite miss it but i was 12 . What i remember is I was sitting in the auditorium of the Modem Languages Building at U of M for Jim Loudon's AstroFest . I think i was one of the youngest there for the voyager 1 and 2 encounters . |
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Nov 20 2009, 10:32 AM
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#36
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Member Group: Members Posts: 796 Joined: 27-February 08 From: Heart of Europe Member No.: 4057 |
Great work! If I might suggest something, flat fielding the images would get rid of the bright corners in the images. Thanks! I used only the dark frame subtract from these images. Flat fields (which I have) cause partially destruction of the details. Normally I use the images from dark side of Neptune or Saturn. Yesterday I downloaded the plaque images, but I don't see any advances over the dark side images. Maybe the problem is in the setup, so I'm still trying new procedures. -------------------- |
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Nov 20 2009, 11:29 AM
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#37
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Senior Member Group: Members Posts: 3648 Joined: 1-October 05 From: Croatia Member No.: 523 |
ThankFlat fields (which I have) cause partially destruction of the details. That doesn't sound right. They should only affect vignetting, dust rings, and other static noise (differences in sensitivity, etc.) in the instrument. Do you mean the introduce even more noise into the images? When you say you use images of Saturn/Neptune dark sides, how do you get a flatfield out of them? -------------------- |
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Nov 20 2009, 12:13 PM
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#38
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Member Group: Members Posts: 796 Joined: 27-February 08 From: Heart of Europe Member No.: 4057 |
That doesn't sound right. They should only affect vignetting, dust rings, and other static noise (differences in sensitivity, etc.) in the instrument. Do you mean the introduce even more noise into the images? When you say you use images of Saturn/Neptune dark sides, how do you get a flatfield out of them? The dark side images are for the dark frames (but in the past, I was experimenting with some adjustment in brightness level, inverting images and so on, and applicating this like flatfield). Flatfields (from the plaque images) don't introduce more noise. They correct images, but too much! Faint details are gone. Maybe I'm working with wrong images, so I'm experimenting with setup and different images. For now, I'm still not satisfied with the results. -------------------- |
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Nov 20 2009, 02:29 PM
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#39
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Member Group: Members Posts: 378 Joined: 21-April 05 From: Portugal Member No.: 347 |
Tho have good results in image calibration, you should use a master flat field, composed of an average of many many individual flat field images (dozens).
The same goes for the dark fields. Also, don't forget the bias fields that are necessary to prevent introducing noise in the process. Everything should be processed in at least a 16bit depth to prevent any data loss. -------------------- _______________________
www.astrosurf.com/nunes |
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Nov 20 2009, 03:50 PM
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#40
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Interplanetary Dumpster Diver Group: Admin Posts: 4404 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
I use different dark frames and flat fields for different parts of the mission - it isn't consistent, and I do some other black magic to cut down on detail destruction. It doesn't perfectly fix the corners, but it does subdue it somewhat. I also convert everything to 16 bit before beginning any processing. This cuts down on detail destruction as well.
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Nov 24 2009, 09:22 PM
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#41
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Member Group: Members Posts: 796 Joined: 27-February 08 From: Heart of Europe Member No.: 4057 |
Io shadow on Jupiter (and interesting clouds). Resolution is around 9.7 km/pix. Color is from CH4_JS, orange and violet filter. Finally I found good flatfield image, so It's flatfielded.
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Dec 7 2009, 10:49 AM
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#42
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Member Group: Members Posts: 796 Joined: 27-February 08 From: Heart of Europe Member No.: 4057 |
Callisto colorised mosaic. Mosaic is composed from nine NAC images and color information from WAC images (blue, orange and clear filter). Voyager 1 distance from Callisto approximately 326 000 km. Resolution is 3 km/pix.
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Dec 19 2009, 05:12 PM
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#43
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Member Group: Members Posts: 796 Joined: 27-February 08 From: Heart of Europe Member No.: 4057 |
Maasaw Patera from Voyager 1. Colorised from WAC images (violet, orange) and clear NAC images.
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Dec 19 2009, 05:22 PM
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#44
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Interplanetary Dumpster Diver Group: Admin Posts: 4404 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
NICE!!!
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Dec 19 2009, 06:58 PM
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#45
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Merciless Robot Group: Admin Posts: 8784 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Damn straight! That's beautiful, Machi.
-------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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