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MEX VMC - Back on, and online!
djellison
post Aug 22 2008, 01:58 PM
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I heard about this 24 hours ago, and couldn't believe it - this is EXACTLY what has been missing from ESA. MASSIVE kudos to the ESOC MEX flight ops team for doing it

http://www.esa.int/SPECIALS/VMC/index.html

The last time I wrote a post and hit 'submit' at UMSF with a smile this big on my face, was when Oppy successfully got out of Purgatory.
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ormstont
post Sep 13 2008, 08:23 PM
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Well, part of the difficulty is that we have no way of predicting how bright Mars will be in a given location at a given phase angle. I'm sure one exists but our aim is always to allow the public to guide VMC activities - as I say, you are the operators of this instrument. If anyone comes up with a way of predicting it then I'd be more than happy to implement it!! I implemented the 4 step exposure setting as a workaround for this - guaranteeing whatever the observation we should get some well-exposed shots.

That's a good point about knowing the exposure settings - I'll see how we can work that into the routine flow of information and processing of each image. For a guideline though, the first image of every observation is always 14ms. For the rest of the observations I'd have to look for you on Monday at work, will do that and get back to you then.

For the flat field - I'm vaguely aware of what the term means - would it be a long exposure image with the spacecraft pointed at space? If you let me know roughly what I need to command MEX/VMC to do then I'll try and schedule a slot when we can do it. I know I use this as a mantra...but it's everyone's instrument, you let us know what to do!


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ugordan
post Sep 13 2008, 08:41 PM
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QUOTE (ormstont @ Sep 13 2008, 10:23 PM) *
would it be a long exposure image with the spacecraft pointed at space?

That would be a dark frame, used for figuring out how the background signal increases with exposure (varies with temperature, hot pixels, etc). Part of wanting the exposure setting comes from the desire to have a rough model for dark background - two separate exposure images of a same target will produce different colors for different amounts of background signal. For example, a short exposure with VMS typically shifts overall colors towards blue as the background (grayish) overwhelms the Mars signal.

A flat-field is usually produced by imaging a sufficiently bland target so any noise in the image is variations in pixel sensitivity, crud in the optics, vignetting etc. This can be divided out from subsequent images to provide better S/N ratio. I don't expect we can get a look at a bland target now that we're at Mars, that sort of thing could have been done back on Earth, but then again this is not a scientific camera so most likely wasn't "calibrated" this way.


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Tman
post Sep 13 2008, 10:27 PM
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QUOTE (ugordan @ Sep 13 2008, 10:41 PM) *
A flat-field is usually produced by imaging a sufficiently bland target so any noise in the image is variations in pixel sensitivity, crud in the optics, vignetting etc. This can be divided out from subsequent images to provide better S/N ratio.

For example, the Mars Rover's lenses have also a couple of "noises" by now, beside their vignetting.
This image shows clouds on sol 1647 and this image from sol 1645 only the dirt on the lens. As a "fieldwork" flatfield you can use the inverted sol 1645 image for some clearing.


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Posts in this topic
- djellison   MEX VMC - Back on, and online!   Aug 22 2008, 01:58 PM
- - djellison   FWIW - I've attempted to debayer a tiny piece ...   Aug 22 2008, 02:57 PM
- - djellison   I THINK I got a bit cleverer in making selections ...   Aug 22 2008, 03:20 PM
|- - ugordan   Wow, great work, Doug. My method of making a Bayer...   Aug 22 2008, 03:25 PM
|- - Tman   QUOTE (ugordan @ Aug 22 2008, 05:25 PM) H...   Aug 22 2008, 03:46 PM
- - Stu   ESA often get a hard time here for what they do - ...   Aug 22 2008, 03:23 PM
- - PDP8E   I always though that the Lunar Prospector team was...   Aug 22 2008, 03:24 PM
|- - djellison   QUOTE (PDP8E @ Aug 22 2008, 04:24 PM) I a...   Aug 22 2008, 03:32 PM
- - djellison   Oh boy oh boy http://esamultimedia.esa.int/multi...   Aug 22 2008, 04:06 PM
|- - ugordan   I'm gonna give it a go at writing an app for a...   Aug 22 2008, 04:10 PM
|- - Juramike   Even better, it looks like they'd like submiss...   Aug 22 2008, 04:37 PM
|- - tedstryk   QUOTE (Juramike @ Aug 22 2008, 04:37 PM) ...   Aug 22 2008, 06:45 PM
|- - ugordan   Nice catch, Tman! Looks like clouds to me, rot...   Aug 22 2008, 07:06 PM
- - Paolo Amoroso   Does the Picasa logo on VMC images imply that they...   Aug 22 2008, 04:42 PM
|- - ugordan   I've got a basic app going, it performs a rudi...   Aug 22 2008, 06:00 PM
||- - djellison   QUOTE (ugordan @ Aug 22 2008, 07:00 PM) W...   Aug 22 2008, 08:31 PM
||- - ugordan   To be honest, coding that particular bit was easy....   Aug 22 2008, 09:34 PM
||- - slinted   Kudos to the ESA and MEX teams! This is an ex...   Aug 22 2008, 11:44 PM
|- - Paolo Amoroso   QUOTE (Paolo Amoroso @ Aug 22 2008, 06:42...   Aug 22 2008, 06:33 PM
- - Tman   Very nice Gordan! What could that illuminated...   Aug 22 2008, 06:27 PM
- - Paolo Amoroso   Are you able to use the Celestia scripts? I downlo...   Aug 22 2008, 06:36 PM
|- - Astro0   QUOTE (Paolo Amoroso @ Aug 23 2008, 04:36...   Aug 23 2008, 03:57 AM
|- - Paolo Amoroso   QUOTE (Astro0 @ Aug 23 2008, 05:57 AM) I ...   Aug 23 2008, 12:27 PM
|- - ugordan   A dodgy first version of the tool: It takes an in...   Aug 23 2008, 02:26 PM
|- - Paolo Amoroso   QUOTE (Paolo Amoroso @ Aug 23 2008, 02:27...   Aug 23 2008, 02:34 PM
|- - Astro0   Paolo, see if you can download Celestia 1.5.0. It ...   Aug 23 2008, 11:32 PM
|- - Paolo Amoroso   QUOTE (Astro0 @ Aug 24 2008, 01:32 AM) Pa...   Aug 24 2008, 02:35 PM
- - Stu   Hmmm... why do the words "Kids", "n...   Aug 22 2008, 09:45 PM
- - djellison   I was thinking 'pig' and err...'poo...   Aug 22 2008, 10:00 PM
- - jekbradbury   For those who would rather not manually run each o...   Aug 24 2008, 02:28 AM
- - Tman   The VMC public gallery has opened http://www.esa.i...   Aug 26 2008, 07:16 PM
- - Stu   In advance of him joining UMSF I've been asked...   Aug 27 2008, 04:13 PM
- - ormstont   Thanks to Stu for passing on the message, I'm ...   Aug 27 2008, 07:18 PM
|- - Paolo Amoroso   QUOTE (ormstont @ Aug 27 2008, 09:18 PM) ...   Aug 28 2008, 11:29 AM
- - imipak   I'm only an "armchair UMSFer", with ...   Aug 27 2008, 09:10 PM
- - Juramike   Here is an GIF animation I made from a sequence of...   Aug 28 2008, 04:57 AM
- - ormstont   Phobos and Deimos would both be fun targets, the b...   Aug 28 2008, 02:15 PM
- - chiron   Hi everybody I worked the last days on a program ...   Aug 29 2008, 11:07 AM
|- - tedstryk   I had a go at the July 29, 2008 dataset. Man, thi...   Aug 29 2008, 02:03 PM
- - ormstont   Tough stuff to work with indeed makes it all the ...   Aug 29 2008, 05:41 PM
|- - tedstryk   Thanks! I am headed out on vacation, but I wi...   Aug 29 2008, 06:42 PM
- - Juramike   Assembled mosaic from June 22, 2008 series of imag...   Aug 30 2008, 02:24 AM
- - Juramike   Handy little guide and detailed explanation of the...   Aug 30 2008, 03:56 AM
- - JTN   QUOTE (Juramike @ Aug 30 2008, 04:56 AM) ...   Aug 30 2008, 04:15 PM
- - Paolo Amoroso   It would be useful for the VMC site to have an RSS...   Aug 31 2008, 01:49 PM
- - ormstont   Sorry for being a bit quiet - as you can probably ...   Sep 4 2008, 03:56 PM
|- - Paolo Amoroso   QUOTE (ormstont @ Sep 4 2008, 05:56 PM) I...   Sep 5 2008, 03:11 PM
- - Stu   re your "mystery object"... Perhaps...?   Sep 4 2008, 06:43 PM
- - ormstont   Definitely hoping for Martians (then we'd have...   Sep 5 2008, 11:26 AM
- - ormstont   Ok...image gallery is online on the website, along...   Sep 5 2008, 02:54 PM
- - djellison   That is unusual. At first I thought it might be a...   Sep 5 2008, 03:10 PM
- - Stu   I may be wrong (probably am) but think this might ...   Sep 5 2008, 03:17 PM
- - remcook   cool, looks like a volcano eruption it's not ...   Sep 5 2008, 03:40 PM
|- - ustrax   I've been far away for so long that I've b...   Sep 5 2008, 03:55 PM
|- - Paolo Amoroso   QUOTE (ustrax @ Sep 5 2008, 05:55 PM) [.....   Sep 5 2008, 04:09 PM
|- - ustrax   In this specific image it looks to me that the sha...   Sep 5 2008, 05:02 PM
- - Stu   How about a meteoroid impact that sent up a big du...   Sep 5 2008, 03:57 PM
|- - ustrax   I'm here... This is what I mean: Looks to...   Sep 5 2008, 04:06 PM
- - ormstont   Just to put my two cents in, you're right that...   Sep 5 2008, 05:53 PM
|- - ustrax   dear Ormstont, I am sorry to be a bit limited in t...   Sep 6 2008, 10:12 AM
|- - ugordan   It definitely appears to be atmospheric as the sha...   Sep 6 2008, 07:02 PM
|- - Juramike   Nice animation, Gordan! As you've shown, ...   Sep 6 2008, 07:40 PM
|- - ustrax   QUOTE (ugordan @ Sep 6 2008, 08:02 PM) It...   Sep 6 2008, 08:11 PM
||- - ugordan   QUOTE (ustrax @ Sep 6 2008, 10:11 PM) the...   Sep 6 2008, 08:43 PM
||- - TheChemist   QUOTE (ugordan @ Sep 6 2008, 11:43 PM) Yo...   Sep 6 2008, 08:47 PM
||- - ustrax   QUOTE (TheChemist @ Sep 6 2008, 09:47 PM)...   Sep 6 2008, 09:21 PM
||- - ugordan   QUOTE (ustrax @ Sep 6 2008, 11:21 PM) Now...   Sep 6 2008, 09:23 PM
||- - ustrax   QUOTE (ugordan @ Sep 6 2008, 10:23 PM) Co...   Sep 6 2008, 09:27 PM
|- - Paolo Amoroso   QUOTE (ugordan @ Sep 6 2008, 09:02 PM) It...   Sep 6 2008, 08:12 PM
||- - Paolo Amoroso   QUOTE (Paolo Amoroso @ Sep 6 2008, 10:12 ...   Sep 7 2008, 02:40 PM
||- - ugordan   Here's a new version of VMC2RGB, this time imp...   Sep 8 2008, 09:50 PM
|- - siravan   QUOTE (ugordan @ Sep 6 2008, 02:02 PM) Ba...   Sep 6 2008, 11:08 PM
|- - ugordan   Yep, it appears I messed up the calculation of (at...   Sep 6 2008, 11:39 PM
- - stevesliva   Does fog cast a shadow? Would it be forming above...   Sep 8 2008, 10:18 PM
- - ormstont   Ok...more info on our strange cloud...we've go...   Sep 11 2008, 10:08 AM
- - remcook   yes, I think 80 km is a normal altitude for these ...   Sep 11 2008, 11:41 AM
- - ormstont   Wow...you beat me to posting the link I've ju...   Sep 11 2008, 01:45 PM
- - elakdawalla   I'd like to include one of the VMC crescent im...   Sep 12 2008, 09:38 PM
|- - ugordan   All 2008 crescents indeed appear to be severely ov...   Sep 12 2008, 11:36 PM
- - ormstont   So, looks like our other MEX instrument teams are ...   Sep 13 2008, 07:20 PM
|- - ugordan   I'd be interested in knowing what the difficul...   Sep 13 2008, 07:24 PM
- - ormstont   Well, part of the difficulty is that we have no wa...   Sep 13 2008, 08:23 PM
|- - ugordan   QUOTE (ormstont @ Sep 13 2008, 10:23 PM) ...   Sep 13 2008, 08:41 PM
|- - Tman   QUOTE (ugordan @ Sep 13 2008, 10:41 PM) A...   Sep 13 2008, 10:27 PM
|- - Paolo Amoroso   QUOTE (ugordan @ Sep 13 2008, 10:41 PM) I...   Sep 14 2008, 09:54 AM
- - ormstont   Ok, get what you're going for there - the only...   Sep 14 2008, 11:21 AM
|- - ugordan   I don't personally think a dark frame would be...   Sep 14 2008, 05:43 PM
- - jekbradbury   I am trying to organize the images by position in ...   Sep 14 2008, 08:57 PM
- - ormstont   QUOTE (ugordan @ Sep 14 2008, 07:43 PM) T...   Sep 15 2008, 08:06 AM
- - jekbradbury   That was exactly what I was looking for. Taking i...   Sep 16 2008, 01:56 AM
- - Juramike   I finally downloaded Celestia (slaps head, why did...   Sep 16 2008, 04:21 AM
- - Juramike   Interesting how both the "mystery cloud...   Sep 16 2008, 04:30 AM
- - ormstont   QUOTE (jekbradbury @ Sep 16 2008, 03:56 A...   Sep 16 2008, 08:12 AM
- - Juramike   It's baaaack! Another cloud sequence at s...   Sep 17 2008, 04:43 AM
- - ormstont   Interesting that we might have a cloud factory on ...   Sep 17 2008, 09:59 AM
- - ormstont   Just a quick plug - got some more lovely shots fro...   Sep 17 2008, 02:42 PM
- - Juramike   The thing that's been puzzling me is the appea...   Sep 17 2008, 02:51 PM
- - djellison   I love this camera.   Sep 17 2008, 03:07 PM
- - Juramike   Here is an attempted mosaic of the "relativel...   Sep 18 2008, 04:31 AM
- - Juramike   There are few guarantees in life... but finding cl...   Sep 20 2008, 04:01 AM
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