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Radar And Mariner 10, Best possible mapping, pre-Messenger
JRehling
post Apr 28 2005, 06:21 PM
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peter59
post Dec 30 2007, 09:13 AM
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I recognize that many of you are waiting for new images of Mercury, but you can't also see old images.

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Tape MVE_033 Image 091 (29 November 1973)


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Free software for planetary science (including Cassini Image Viewer).
http://members.tripod.com/petermasek/marinerall.html
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tedstryk
post Jan 4 2008, 09:55 PM
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I have been playing around with some Mariner-10 shots. I experimented with color, but Mariner 10's camera had such a weird filter selection that, when combined with calibration issues, make things really difficult.

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Here is a cleaner view of the south polar view I did a while back, both in original form and from a high pass filter. There is a larger mosaic, but since it depends on a heavy amount of reprojection, I decided to stick with the wide angle data, as Mercury's topography makes significant reprojection obvious.

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Here is the 3rd encounter Discovery Rupes mosaic, with a small gapfill from stacked first-encounter images to fill the sliver between the two lower images. Also, I did a stack of the "Discovery Dome" area using third encounter images.

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JRehling
post Jan 4 2008, 10:41 PM
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tedstryk
post Jan 4 2008, 10:44 PM
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True-color is such a relative thing....I think even Messenger stuff might go through a few variations as we have seen in color images from many early missions....the problem is the lack of a standard for subtle balancing work. By the way, if anyone downloaded the image right after I posted it, I posted the wrong file...it has now been corrected.


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JRehling
post Jan 4 2008, 10:57 PM
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tedstryk
post Jan 5 2008, 12:04 AM
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What I am trying to say is that it might take a while before images can be calibrated to the point of providing color of the quality of, for example, Cassini images. For the other planets, we at least have good earthbased color data. Mercury images, on the other hand, are so damaged by atmospheric refraction and (in daylight) scattered sunlight that they don't provide much of a reference point. In other words, I can see the color images being produced two years from now looking very different from the ones we will see in the next few weeks.

Incidentally, Mariner 10, while having odd filters, had a great camera, but unfortunately, as has been mentioned before, the camera pointing resembles footage from an drunken camera man. That makes the images very hard to assemble, especially using color. I always wondered why Mark Robinson and his team only produced a color ratio map of a small area. After trying to work with the data, I understand.


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ugordan
post Jan 5 2008, 12:42 AM
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I personally think any color uncertainties in the first images will be smaller than any comparative "ground-truth" later, onboard spectrometer corrections will suggest. Mercury, after all, isn't likely to be a very spectrally complex place like Jupiter, Io or Saturn. It will probably have gentle spectral slopes and that's where even discrete filter MDIS composites can come very close in "true color" to what a more precise integration through many spectral wavelengths (approximating the actual spectral curve to a good degree) would give. Messenger carries a spectrometer, although apparently not an imaging one. MASCS will probably be good enough anyway, just like Cassini's VIMS can be used at Saturn.
The MER rovers don't have that kind of training tool and all their surface "true" color views are basically generated on the basis of being the most probable result of solving some integral equations IIRC.

I'd like to know if Cassini image products were trained on groundbased imagery (I know my first reactions to the first Saturn color shots were how different it looks than from other earthbased views I saw) because the vantage points were different and direct color calibration would be difficult due to phase angle effects etc. There is certainly variation in color results even today from CICLOPS image releases, although less than before. I'm saying that with good spectrometers onboard you don't even need groundbased observations for good color quality and this might very well turn out to be the case with Mercury.

Color me happy if Mercury doesn't turn out as spectrally grey as our own Moon. Even a brownish hue is some personality.


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tedstryk
post Jan 5 2008, 01:20 AM
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I think the lack of color is the problem. With color variations being so faint, balancing is made very difficult. For "natural" views, this may be only subtly visible, but it may effect the warm/cool color appearance, which is why I say there may be a lot of variation at first (it really depends just what color Mercury really is to see whether this materializes). I have never thought it too terribly important to replicate the human eye in planetary images - the RGB response of our eyes is so arbitrary for planetary targets that unless we are generating graphics for astronaut training, using other wavelengths that better highlight a world's compositional variations is a great technique. However the Mariner 10 filters set is just weird. It does have a dedicated yellow filter, but it was seldom (if ever) used. There is so much overlap between the filters used here (UV = blue, blue = green, and "minus UV" = red) that isolating three channels is quite treacherous.

On a more abstract level, I often wonder how much variation there is between different sets of eyes. I have gotten into long debates with people who are looking through my telescope and could swear it has a cool hue while others swear it has a warm hue. I have noticed that on many nights, it looks cool in my left eye and warm in my right eye. Perhaps this is what gives me my opinion on color.


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Posts in this topic
- JRehling   Radar And Mariner 10   Apr 28 2005, 06:21 PM
- - Decepticon   http://www.lpl.arizona.edu/~rhill/alpo/mer...f/mes...   May 11 2005, 12:20 AM
- - Decepticon   http://www.psrd.hawaii.edu/WebImg/HarmonRadarFig2....   May 11 2005, 12:25 AM
|- - lyford   QUOTE (Decepticon @ May 10 2005, 04:25 PM)htt...   May 11 2005, 01:48 AM
|- - JRehling   [...]   May 11 2005, 04:47 PM
|- - tedstryk   (Added detail: One of the major methodologies in h...   May 11 2005, 07:18 PM
|- - JRehling   [...]   May 11 2005, 09:34 PM
- - Phil Stooke   I too am interested in this topic of pre-Messenger...   May 14 2005, 04:51 PM
|- - JRehling   [...]   May 16 2005, 12:04 AM
|- - Bob Shaw   The mercury maps are astonishing at this stage in ...   May 16 2005, 12:50 PM
|- - JRehling   [...]   May 16 2005, 08:45 PM
|- - Bob Shaw   Thanks!   May 16 2005, 09:11 PM
- - Chmee   These are great images obtained from the ground. ...   May 17 2005, 04:43 PM
|- - lyford   QUOTE (Chmee @ May 17 2005, 08:43 AM)These ar...   May 17 2005, 04:53 PM
|- - JRehling   [...]   May 17 2005, 05:59 PM
|- - Bob Shaw   A 'family portrait' of the Solar System by...   May 17 2005, 07:45 PM
- - djellison   iirc - Hubble has a minimum sun angle which is can...   May 17 2005, 04:54 PM
- - Chmee   I wonder if the concern is the actual damage if Hu...   May 17 2005, 05:27 PM
- - gndonald   Erwin Van Der Velden's home page has moved. Hi...   Aug 15 2005, 03:26 PM
|- - Bob Shaw   QUOTE (gndonald @ Aug 15 2005, 04:26 PM)Erwin...   Aug 15 2005, 07:08 PM
|- - OWW   QUOTE (Bob Shaw @ Aug 15 2005, 07:08 PM)Wow...   Nov 15 2005, 07:17 PM
|- - DonPMitchell   Here's one of Ksanfomality's new photos of...   May 8 2006, 05:56 AM
- - PhilHorzempa   I believe that 'Sky and Telescope' publish...   May 20 2006, 05:04 AM
|- - tedstryk   http://cps.earth.northwestern.edu/M10/TXT/encounte...   May 20 2006, 04:40 PM
||- - PhilHorzempa   QUOTE (tedstryk @ May 20 2006, 12:40 PM) ...   May 23 2006, 03:00 AM
|- - DonPMitchell   QUOTE (PhilHorzempa @ May 19 2006, 10:04 ...   May 21 2006, 03:06 PM
|- - Malmer   QUOTE (DonPMitchell @ May 21 2006, 05:06 ...   May 21 2006, 08:38 PM
|- - DonPMitchell   QUOTE (Malmer @ May 21 2006, 01:38 PM) Th...   May 22 2006, 01:47 AM
|- - PhilHorzempa   QUOTE (Malmer @ May 21 2006, 04:38 PM) Th...   May 27 2006, 05:06 AM
- - edstrick   When Mariner 10 did it's second flyby, as it w...   May 21 2006, 09:09 AM
|- - Bob Shaw   QUOTE (edstrick @ May 21 2006, 10:09 AM) ...   May 21 2006, 11:46 AM
- - dvandorn   You know, I got a book nearly 20 years ago that de...   May 22 2006, 07:08 AM
|- - Bob Shaw   oDoug: Charles A Cross did an interesting mapping...   May 22 2006, 01:54 PM
- - edstrick   Mariner 10 and Voyager had very similar camera sys...   May 22 2006, 08:45 AM
- - Phil Stooke   Charles Cross did some interesting work. He let m...   May 22 2006, 03:35 PM
- - djellison   I am a BAA member - give me some specifics and I...   May 22 2006, 03:47 PM
- - Phil Stooke   I'm sorry, Doug, I don't know any more tha...   May 22 2006, 05:07 PM
- - DonPMitchell   Do you have the ISIS calibration data for the Mari...   May 23 2006, 04:00 AM
- - antipode   Outstanding new Arecibo radar images of equatorial...   Dec 7 2006, 01:52 AM
- - Phil Stooke   Yes, that is an excellent article. Phil   Dec 7 2006, 02:57 AM
- - dvandorn   Too bad it would cost me $30USD to take a loo...   Dec 7 2006, 04:49 AM
|- - tedstryk   http://www.naic.edu/~radarusr/Mercury.pdf You can...   Dec 8 2006, 01:55 PM
|- - angel1801   I always wanted some good full disk coverage of Me...   Dec 8 2006, 03:56 PM
|- - tedstryk   That would be the first author, John Harmon.   Dec 8 2006, 05:17 PM
- - Phil Stooke   This map is a composite of the USGS shaded relief ...   Dec 9 2006, 05:58 PM
- - Tayfun Öner   While reading this thread I realized I made the cy...   Dec 9 2006, 06:37 PM
- - dvandorn   Mucho, mucho gracias for the maps, Phil and Tayfun...   Dec 9 2006, 08:10 PM
- - Phil Stooke   I have updated my composite map of Mercury, adding...   Apr 8 2007, 06:18 PM
|- - JRehling   [...]   Apr 9 2007, 08:34 PM
- - Phil Stooke   ... and the southern hemisphere: Phil   Apr 8 2007, 06:19 PM
- - volcanopele   Using the above map, I ran through the first MESSE...   Apr 8 2007, 07:34 PM
- - ugordan   Nice view VP. One thing I always wondered about vi...   Apr 8 2007, 07:48 PM
- - Phil Stooke   That is really cool, VP, thanks. ugordan, I thi...   Apr 8 2007, 08:30 PM
- - ugordan   I see, Phil. I was under the impression that in 3D...   Apr 8 2007, 08:39 PM
- - Phil Stooke   I don't mean you! But I encounter so many...   Apr 9 2007, 03:16 AM
|- - lyford   QUOTE (Phil Stooke @ Apr 8 2007, 08:16 PM...   Apr 9 2007, 03:51 PM
|- - tedstryk   All this is well and good, Phil, but let me ask yo...   Apr 9 2007, 07:02 PM
- - Phil Stooke   Yes, Ted, I use them to make cootie-catchers... o...   Apr 9 2007, 07:27 PM
|- - tfisher   QUOTE (Phil Stooke @ Apr 9 2007, 03:27 PM...   Apr 11 2007, 03:33 AM
- - PhilHorzempa   The significance of all of this effort to squeeze ...   Apr 10 2007, 06:05 PM
- - Phil Stooke   I will go on record saying that I don't believ...   Apr 10 2007, 06:09 PM
|- - JRehling   [...]   Apr 10 2007, 11:27 PM
|- - tedstryk   QUOTE (Phil Stooke @ Apr 10 2007, 06:09 P...   Apr 10 2007, 11:34 PM
|- - volcanopele   Why do people see vague, dark, circular albedo mar...   Apr 11 2007, 01:27 AM
|- - tedstryk   So that, should they get lucky, they can claim the...   Apr 11 2007, 09:52 AM
- - Tayfun Öner   As the first encounter is getting near, I plan to ...   Dec 6 2007, 01:48 PM
- - Phil Stooke   Yes, this is a good idea. It will be interesting ...   Dec 6 2007, 07:22 PM
|- - JRehling   [...]   Dec 6 2007, 07:34 PM
|- - nprev   QUOTE (JRehling @ Dec 6 2007, 11:34 AM) W...   Dec 6 2007, 08:21 PM
- - 4th rock from the sun   Hi, Ok, here's the familiar Mercury map with ...   Dec 6 2007, 09:01 PM
- - Tayfun Öner   Here it is. Some notes about the map: It was const...   Dec 6 2007, 09:39 PM
- - Tayfun Öner   And here is version 2 with some fills.   Dec 7 2007, 09:33 AM
- - CAP-Team   Here's a map of Mercury that I've been usi...   Dec 7 2007, 05:58 PM
|- - gcecil   QUOTE (CAP-Team @ Dec 7 2007, 12:58 ...   Dec 8 2007, 02:11 AM
|- - ElkGroveDan   Welcome Gerald. Thanks for the links to your pape...   Dec 8 2007, 02:42 AM
- - Tayfun Öner   Hi gcecil, thanks for the map but it seems to have...   Dec 8 2007, 10:17 AM
- - edstrick   Mariner 10 took a series of approach <crescent...   Dec 8 2007, 11:46 AM
- - Tayfun Öner   I am not sure if edstrick's post is an answer ...   Dec 8 2007, 12:13 PM
|- - gcecil   QUOTE (Tayfun Öner @ Dec 8 2007, 07:13 AM...   Dec 8 2007, 01:19 PM
- - Tayfun Öner   Here is Version 3 with optical data added from Bau...   Dec 8 2007, 02:35 PM
- - edstrick   I didn't spot the scale problem, I was just po...   Dec 9 2007, 10:11 AM
|- - tedstryk   Here is an example of a Mariner set that shows a b...   Dec 14 2007, 03:56 AM
- - peter59   I recognize that many of you are waiting for new i...   Dec 30 2007, 09:13 AM
|- - tedstryk   I have been playing around with some Mariner-10 sh...   Jan 4 2008, 09:55 PM
|- - JRehling   [...]   Jan 4 2008, 10:41 PM
|- - tedstryk   True-color is such a relative thing....I think eve...   Jan 4 2008, 10:44 PM
|- - JRehling   [...]   Jan 4 2008, 10:57 PM
|- - tedstryk   What I am trying to say is that it might take a wh...   Jan 5 2008, 12:04 AM
|- - ugordan   I personally think any color uncertainties in the ...   Jan 5 2008, 12:42 AM
|- - tedstryk   I think the lack of color is the problem. With co...   Jan 5 2008, 01:20 AM
|- - JRehling   [...]   Jan 5 2008, 05:46 AM
|- - hendric   QUOTE (tedstryk @ Jan 4 2008, 07:20 PM) O...   Jan 6 2008, 04:19 AM
- - nprev   My brother is both color-blind (red-green, which a...   Jan 6 2008, 05:35 AM
- - peter59   Mariner 10 - First encounter with Mercury. Image...   Jan 7 2008, 07:03 PM
|- - tedstryk   Here is a more distant approach view showing a lot...   Jan 7 2008, 10:00 PM
- - peter59   Mariner 10 - First encounter with Mercury (March 2...   Jan 9 2008, 06:47 PM
|- - JRehling   [...]   Jan 9 2008, 06:52 PM
|- - tedstryk   For the record, since the Mariner-10 outbound mosa...   Jan 10 2008, 05:25 AM
|- - JRehling   [...]   Jan 10 2008, 06:55 PM
- - edstrick   I never understood why they didn't include tha...   Jan 27 2008, 08:38 AM
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