Viking 1 Lander, 31st July 1977 |
Viking 1 Lander, 31st July 1977 |
May 14 2005, 09:04 PM
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#1
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Founder Group: Chairman Posts: 14431 Joined: 8-February 04 Member No.: 1 |
Just perusing thru the Viking Lander dataseta ( amazing, less than 1CD each - and I've got 9 DVD's for Spirits Pancam Sols 1-270 alone ) and found this three-colour set - I thought it looked fab, and I've never seen it before. Here's the info... QUOTE Product Id 11E123-GRN
Spacecraft Name VIKING_LANDER_1 Instrument Name CAMERA_1 Mission Phase Name EXTENDED MISSION Target Name MARS Start Time 1977-07-31T08:08:51Z Stop Time 1977-07-31T08:16:12Z Planet Day Number 366 Local Time 10.70 Start Azimuth 162.50 degrees Stop Azimuth 245.00 degrees Center Elevation 10.00 degrees Sampling Parameter Interval 0.12 degrees Observation Type COLOR TRIPLET Filter Name GREEN Gain Number 4 Offset Number 1 Detector Temperature -18.10 Dust Flag FALSE Start Rescan Number 0 Total Rescan Number 0 Scan Rate 16000 BPS Data Path Type RECORDED UHF LINK Line Samples 689 Missing Samples 3 |
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May 23 2005, 02:48 AM
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#2
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Member Group: Members Posts: 123 Joined: 21-February 05 Member No.: 175 |
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May 23 2005, 09:48 PM
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#3
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Member Group: Members Posts: 378 Joined: 21-April 05 From: Portugal Member No.: 347 |
Very good!
I think the Viking missions deserve a on-line gallery like the current MER rovers have at http://www.lyle.org/%7Emarkoff/. Given the small amount of data it might even be simpler to do! -------------------- _______________________
www.astrosurf.com/nunes |
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May 24 2005, 02:13 PM
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#4
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Interplanetary Dumpster Diver Group: Admin Posts: 4404 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
QUOTE (4th rock from the sun @ May 23 2005, 09:48 PM) Very good! I think the Viking missions deserve a on-line gallery like the current MER rovers have at http://www.lyle.org/%7Emarkoff/. Given the small amount of data it might even be simpler to do! It would be nice to make a site utilizing all planetary landers (on Venus, Mars, the moon, and Titan). Perhaps this is a project that could be undertaken after the MER mission (since if MSL gets delayed, which looks certain without a political rescue and barring some scout lander coming from nowhere, the post-MER period might provide a nice chance to dig back in the archives - I know there will be the Phoenix interlude, but I suspect it will be shortlived due to the highl latitude coupled with solar power). Ted -------------------- |
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May 24 2005, 02:18 PM
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#5
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Founder Group: Chairman Posts: 14431 Joined: 8-February 04 Member No.: 1 |
Well - I'll certainly go thru and start making all the RGB combos I can find for V1 and V2 - but the only problem I have is the same problem I have with Pathfinder .img's
They're not exactly RAD's are they Some will come out looking about right but many are obviously not properly calibrated as one would find with an MER RAD with img2png -r I think this might be an investigation for super-bjorn If you wish to grab a burnable-to-CD .img of each Viking archive.. http://pdsimg.jpl.nasa.gov/data/vl1_vl2-m-lcs-2-edr-v1.0/ The folders of the same names are simply the full content of the .img (which is a sort of .iso) Looking here - http://pdsimg.jpl.nasa.gov/data/vl1_vl2-m-.../vl_0001/calib/ and especially here http://pdsimg.jpl.nasa.gov/data/vl1_vl2-m-...lib/calinfo.htm I'm sure the information to generate radiometrically calibrated data is there - I think Bjorn may just need to re-do a bit of IMG2PNG to do it. If he can do that - I'll happily generate every RGB set I can find. I think MPF's IMP needs the same attention in Img2Png'ing Doug |
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May 24 2005, 03:08 PM
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#6
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Interplanetary Dumpster Diver Group: Admin Posts: 4404 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
QUOTE (djellison @ May 24 2005, 02:18 PM) Well - I'll certainly go thru and start making all the RGB combos I can find for V1 and V2 - but the only problem I have is the same problem I have with Pathfinder .img's They're not exactly RAD's are they Some will come out looking about right but many are obviously not properly calibrated as one would find with an MER RAD with img2png -r I think this might be an investigation for super-bjorn If you wish to grab a burnable-to-CD .img of each Viking archive.. http://pdsimg.jpl.nasa.gov/data/vl1_vl2-m-lcs-2-edr-v1.0/ The folders of the same names are simply the full content of the .img (which is a sort of .iso) Looking here - http://pdsimg.jpl.nasa.gov/data/vl1_vl2-m-.../vl_0001/calib/ and especially here http://pdsimg.jpl.nasa.gov/data/vl1_vl2-m-...lib/calinfo.htm I'm sure the information to generate radiometrically calibrated data is there - I think Bjorn may just need to re-do a bit of IMG2PNG to do it. If he can do that - I'll happily generate every RGB set I can find. I think MPF's IMP needs the same attention in Img2Png'ing Doug I have also had trouble in that the slow scanning of the Viking cameras can lead to subtle differences between frames. -------------------- |
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May 24 2005, 03:37 PM
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#7
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Member Group: Members Posts: 154 Joined: 17-March 05 Member No.: 206 |
So does this picture symbolize something? Like giving the middle-finger to the Soviets: "Hey we landed (successfully) here first, so there!"
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May 24 2005, 03:54 PM
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#8
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Founder Group: Chairman Posts: 14431 Joined: 8-February 04 Member No.: 1 |
QUOTE (tedstryk @ May 24 2005, 03:08 PM) I have also had trouble in that the slow scanning of the Viking cameras can lead to subtle differences between frames. iirc - R, G and B were actually scanned at the same time, together. This is how I read the operation of the cameras anyway. The scanning of three channels at the same time ( R,G,B or IR1,IR2,IR3 ) would generate data at the same rate as the high resolution sensors in monochrome ( i.e. 3 channels of .12 degrees = 1 channel of .04 degrees ) i.e. http://pdsimg.jpl.nasa.gov/data/vl1_vl2-m-...xx/12a006bu.htm http://pdsimg.jpl.nasa.gov/data/vl1_vl2-m-...xx/12a006gn.htm http://pdsimg.jpl.nasa.gov/data/vl1_vl2-m-...xx/12a006rd.htm are all part of the same sequence and all started and finished at the same times. Doug |
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May 24 2005, 04:41 PM
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#9
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Solar System Cartographer Group: Members Posts: 10149 Joined: 5-April 05 From: Canada Member No.: 227 |
Chmee: "So does this picture symbolize something? Like giving the middle-finger to the Soviets: "Hey we landed (successfully) here first, so there!" "
No, it doesn't! But seriously... a nice image. Lots of these Viking images are rarely seen and certainly deserve a wider audience. A composite of this color merged with the high res frame of the area would be very impressive too. I know Tim Parker has been doing some super-resolution stuff with these Viking images, too. There was an LPSC abstract a few years ago on it. Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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May 25 2005, 11:33 AM
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#10
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Interplanetary Dumpster Diver Group: Admin Posts: 4404 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
The frames I was working with when I had this problem were the few rare high resolution color images (which never turned out very well anyhow). It never occured to me that the lower resolution scans would be faster
QUOTE (djellison @ May 24 2005, 03:54 PM) QUOTE (tedstryk @ May 24 2005, 03:08 PM) I have also had trouble in that the slow scanning of the Viking cameras can lead to subtle differences between frames. iirc - R, G and B were actually scanned at the same time, together. This is how I read the operation of the cameras anyway. The scanning of three channels at the same time ( R,G,B or IR1,IR2,IR3 ) would generate data at the same rate as the high resolution sensors in monochrome ( i.e. 3 channels of .12 degrees = 1 channel of .04 degrees ) i.e. http://pdsimg.jpl.nasa.gov/data/vl1_vl2-m-...xx/12a006bu.htm http://pdsimg.jpl.nasa.gov/data/vl1_vl2-m-...xx/12a006gn.htm http://pdsimg.jpl.nasa.gov/data/vl1_vl2-m-...xx/12a006rd.htm are all part of the same sequence and all started and finished at the same times. Doug -------------------- |
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May 25 2005, 11:50 AM
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#11
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Founder Group: Chairman Posts: 14431 Joined: 8-February 04 Member No.: 1 |
I must admit - I did occasionally think "well, why not just to colour scans much slower?" when wondering about high res colour
Doug |
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May 25 2005, 11:56 AM
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#12
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Senior Member Group: Members Posts: 1870 Joined: 20-February 05 Member No.: 174 |
The Viking Lander cameras had, as I recall, 12 Photo-diodes per camera. R,G,B,IR1,IR2, IR3 for multispectral imagery, 1 broadband diode for low-rez monochrome imaging, 1 un-amplified diode for direct sun imaging, and 4 hi-rez diodes at fixed focus steps to provide in-focus images at different ranges.
The diodes were mounted in two side-by-side lines, The RGB diodes were in one line, the IR diodes in the other. RGB and IR1-2-3 images are nearly perfectly registered (There is about 1 1/10 pixel error, which is enough to make nasty color fringing if you attempt to enhance IR color data), but there is mis-alignment in the forground between the 2 sets of diodes. Imaging sequences were normally 1.) broadband low rez, 2.) Color low rez, 3.) broadband High-rez (using a selected high rez diode) and 4.) sun imaging. Color (and IR color) images were taken by scanning the same vertical scan line 3 times, then stepping the camera 1 field of view 0.12 deg over, and scanning the next line 3 times, using the 3 color or 3 infrared diodes in sequence. Low-rez diode images were 60 deg high centered at 5 or 10 deg elevation intervals (can't remember). High-rez diode images were 20 deg high. Image widths were variable, in increments of 64 (I think) scans. (64/3 for color) The cameras also had a few "odd" imaging modes. They could take high-rez mode pics using color diodes, over-sampling the low-rez diodes with 0.04 deg sample spacing. HOWEVER, they could only take one color at a time, taking them in sequence, or at the same time of day on subsequent days. Usually, high-rez mode color images have annoying color fringes from sun movement from one image to the next in the sequence. The cameras also had a "motion detection" mode where the camera just continually image one vertical scan line up to a few hundred times or so. Didn't show much other than shadows moving, except for imaging sequences when Phobos's shadow passed over the landing site or nearby and they could see the sky <and foreground, if it was directly across the sun> darken by 10% or so and get the time of mid-eclipse EXACTLY. The cameras returned (unfortunately) 6-bit data, which significantly degraded the IR color data, as there was very very low "color" contrast in IR images. For an imaging sequence, the camera's amplifier "Gain" (sensativity) could be set, as could an "offset" (zero-level) value. If gain was set too high, large parts of the images would be <and sometims were> saturated at a "Digital number" DN level of 63. Offset was generally set to near zero, so true black in the images is usually, THOUGH NOT ALWAYS, near zero in the EDR (experiment data record) data. The simplest way to make quasi-true color images from Viking data is to select an image together with an image of a sunlit calibration test chart taken at a similar time of day at about the same time in the mission. The charts were tilted and didn't get really dusty (they did get some). Adjust gain in the RGB channels till the sunlit gray-steps on the chart are neutral shades of gray. The red patch on the chart will look red, the green patch will look green, but the blue patch will look PURPLE. The Viking lander camera channels had a BIG gap between the response of the green and red channels where they overlap strongly in human vision (yellow and orange wavelengths), and the red channel had significant near IR response, where the blue paint chip had a strong increase in reflectivity in the near IR. Without quantitative remapping of the camera's output into channels matching the color response of the human eye, you cannot get true color data from the lander cameras. |
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May 25 2005, 12:11 PM
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#13
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Founder Group: Chairman Posts: 14431 Joined: 8-February 04 Member No.: 1 |
The eclipse imagery I features in my talk on Saturday ( "It was a smash!" - The front bumper of Chris's Elise" )
http://www.unmannedspaceflight.com/doug_im.../v1_eclipse.jpg The images used were.... http://pdsimg.jpl.nasa.gov/data/vl1_vl2-m-...xx/12f136bu.htm and the two following. What I know about the Viking imaging system stems from about 4 hours of mad panic research last week I think I may have to learn how to do this 'programning' lark - I'm slowly becoming more and more of a 'confused artist' when trying to do some of the things I'd like to do Doug |
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May 25 2005, 04:22 PM
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#14
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Interplanetary Dumpster Diver Group: Admin Posts: 4404 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
Here is my latest attempt at a Viking 2 pan. For some reason, it is nearly impossible to get realistic-looking color saturation with Viking - the images either get to red or too green. One place looks right, and then another place gets out of wack. Ugghhh.
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May 25 2005, 04:45 PM
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#15
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Interplanetary Dumpster Diver Group: Admin Posts: 4404 Joined: 17-February 04 From: Powell, TN Member No.: 33 |
QUOTE (tedstryk @ May 25 2005, 04:22 PM) Here is my latest attempt at a Viking 2 pan. For some reason, it is nearly impossible to get realistic-looking color saturation with Viking - the images either get to red or too green. One place looks right, and then another place gets out of wack. Ugghhh. Edit: Actually, for images without saturated areas, I have found a solution. Enlarge the image, resample it, and shrink it back (it can be done without enlarging, but it degrades resolution further). Then overlay the color product over a mix of the three original images. Due to the resampling, the colors are not as harsh. Here is an example: -------------------- |
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