Chuck I copied if from the web minus the pictures: Posted by: KanoOn: Sun January, 18 2004 @ 03:34 GMTThis article is a brief summarised explanation of how the PanCam on the Mars Spirit Rover operates, in relation to the strange appearance of the calibration sundial in some pictures. The question was first raised by ATS member AArchAngel, and has been discussed at length in this AboveTopSecret forum thread and ATSNN story: thread Mars Spirit Rover Picture analysis. In this thread I will attempt to summarise my posts to the larger thread. What are you talking about? Ok, the initial alarm was raised after it was noticed that the color-calibration sundial mounted on the rover, looked quite markedly different in the Mars-Panorama shots compared to its regular appearance. Immediately wide-ranging theories began to pop up. At this stage I knew very little of the particulars of the PanCam so I decided to go and see what the Horses mouth had to say. I sent out a swag of emails to the NASA marsrover team, the Athena Instrument team at Cornell University, and the long shot, an email to Assoc. Professor James Bell. Who is the Pancam Payload Element Lead for the mission. Now, getting no response from the Athena team, and an automated response from the NASA team. I was amazed and delighted to see that Dr. Bell had indeed taken the time out of his busy schedule to help explain this quirk in the panorama pictures. His email response is below: quote: Thanks for writing. The answer is that the color chips on the sundial have different colors in the near-infrared range of Pancam filters. For example, the blue chip is dark near 600 nm, where humans see red light, but is especially bright at 750 nm, which is used as "red" for many Pancam images. So it appears pink in RGB composites. We chose the pigments for the chips on purpose this way, so they could provide different patterns of brightnesses regardless of which filters we used. The details of the colors of the pigments are published in a paper I wrote in the December issue of the Journal of Geophysical Research (Planets), in case you want more details... All of us tired folks on the team are really happy that so many people around the world are following the mission and sending their support and encouragement... Thanks, Jim Bell Cornell U. Chuck Hards <chuckhards@yahoo.com> wrote: Can you give a brief summation of the site? Thanks C. --- Paul Witte wrote:

Apparently some popular sites recently added a link to that page causing an overload on their servers. Try again in a couple days and you shouldn't have a problem. Here is the link again in case you deleted it:

http://www.atsnn.com/story/30048.html

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For those of us who are fans of stereo photography -- and I have been ever since I acquired my first Viewmaster in the early 1950s -- the past few weeks have been an amazing time. Spirit's views often are sent back in stereo pairs, and it's an easy matter to download views and then just free-base view them on the computer screen, if you know the trick to letting your eyes slide views on top of each other. This has been a great treat for me, as it really gives me the feel of being on the surface of another planet, examining even soil in great detail, seeing these views in depth. From the ground in Gustav, Mars has a somehow homey feel. But now another spectacular view of Mars comes up in 3D, Valles Marineris as seen by the European Space Agency's Mars Express. The stereo view posted today is like nothing I've ever seen before. It verges on science fiction. Go to the ESSA site at http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=34316 -- download both Valles pictures, then view them in stereo. It's bizarre enough in two dimensions, but in depth it is astonishing. Best wishes, Joe

Gary, just cross your eyes until the images fuse. Much easier than random-dot stereograms since with those you don't have any references until the images are actually merged. And you discovered that putting them closer together, or reducing them, also makes it easier. If you can't normally focus on a single object about four inches in front of your face (just about duplicates the same eye configuration for freely fusing stereo images at normal reading distance), you won't be able to cross your eyes enough to do it without moving the stereo images further away from your face. Putting them closer together, laterally, helps also but the limit is reached when they are in contact. I do own a stereo viewer and I still prefer just free-fusing images 3 times out of 5, except when my arms aren't long enough... C. --- Gary Liptrot <n7zi@comcast.net> wrote:

Unearthly feast for the eyesJoe, This is just like viewing Random Dot Stereograms except my eyes will only let the images overlap a little less than half... hmmmm.

Ok, I reduced the images to 50 percent in Microsoft Photo Editor (the Windows 98 free default). I could then put them next to each other and given a minute I could bring them together. I wish I had viewers that would let me use the full pictures. I have plans for one somewhere in this mess... B)

de n7zi Gary

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--- Gary Liptrot <n7zi@comcast.net> wrote:

One of my machining magazines shows some cool camera mounts for doing stereo photography.

Usually not even necessary. You only need a "slider" for shooting stuff up-close. For landscapes, just take two shots, one a step to one side from the other. The shots may not have their edges parallel, but you only need to rotate one print slightly until the images are aligned. When I dig out my Hale-Bopp shots, I'll post some pairs in the Gallery. C. __________________________________ Do you Yahoo!? Yahoo! Hotjobs: Enter the "Signing Bonus" Sweepstakes http://hotjobs.sweepstakes.yahoo.com/signingbonus

Have you seen this one? http://www.panoramas.dk/fullscreen3/f2_mars.html ----- Original Message ----- From: "Patrick Wiggins" <paw@trilobyte.net> To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Sent: Tuesday, January 20, 2004 10:47 PM Subject: [Utah-astronomy] Re: Unearthly feast for the eyes

With this current thread about 3-D views of Mars, here's a URL to a page that shows how to make the red/blue glasses.

http://terraweb.wr.usgs.gov/TRS/kids/glasses.html

Patrick

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Hi Gary, It's quite interesting to me. I know the Spirit views are true stereo. But now I wonder about the Mars Express view whether I was simplyh stunned by the alien beauty of the world and thought it looked like it popped out in 3D, or if it was true 3D -- my brain was programmed to see it in depth. Then when I studied the images I couldn't tell if the images really were different. Hummm. Anyway, it's a wonderful and strange view. I have no trouble letting my eyes relax so that I can make two images slide together, just looking at two stereo views side by side. But there's a limit to how far they can go, so I might do the whole image at a small scale or half at a time at a larger scale. Best wishes, Joe