Update: Peter Wellmann creates three views of Mars!

We would like to make a correction on our last blog update from Wednesday; Peter Wellmann had in fact submitted three versions of Mars' North Polar Regions. The corrected versions are all below. To read more about how Peter did his processing, check out the footnotes at the bottom of the page (after the jump..). Enjoy! And thanks, Peter for these impressive results. -- Daniel

The first picture shows almost all of the North Pole, surrounded in a dense cloudy haze. Craters Korolev and Alba Mons have been located easily.

Peter wrote:  “This very interesting VMC-material shows the almost complete North Polar Region and its surrounding area covered with clouds and haze. Identifying the surface details is impossible. Only Korolev crater and Alba Mons could be found. The stunning details below Alba Mons could be high reaching and dense clouds with their shadows. These gigantic clouds extend roughly over 150km. Sometimes sand storms cover the whole planet with dust, but never before have I seen Mars with such a large cloudy and hazy area. The surface structure is clearly visible only in small areas around Alba Mons, even the North Polar Cap is not detected safely, even though the pole is situated right on the terminator. The clouds show an interesting spiral structure, probably induced by coriolis force acting on air streaming out of a high pressure area on the northern hemisphere of a left spinning planet. Although there is little sharp detail in the raw-material I decided to give it a try.”

The second edit shows a similar situation as the first picture, the only difference being that they are on different sides of the hemisphere. This picture shows the complete polar region and the craters Acidalia Planitia, Lyot and Lomonosov could be clearly detected. The entire pole is covered with nicely structured clouds and haze.

Peter wrote: “This very interesting VMC-picture should be seen as supplement to my previous submitted image 2010/11/13. It shows the part of the polar region not visible on the 2010/11/13 image. Almost the entire North Pole and surrounding area is covered with nicely structured clouds and haze. Identifying surface details is not easily accomplished. Only Acidalia Planitia is partly free of clouds, and Lomonosov crater can be easily detected. On a second look the large crater Lyot is seen full size inside a semicircle of clouds. Some other structures are easily detected by comparing with the Celestia image, but we do not know their names. Surface structure is clearly visible only in small areas, even the north polar cap is not detected safely, although the pole is situated right below the terminator. The clouds show an interesting spiral structure, in a large stripe to the left very fine structure is visible. Although there is little sharp detail in the raw-material I decided to give it a try.”

The final image is of the complete North Pole covered in a nicely structured haze. The two pictures of Mars were taken about 4 days apart. Some landmarks were identified under the cloud haze.

Peter wrote: “This picture combines two VMC-operations; the first took place on 2010/11/23, the second only four days later on 2010/11/27. Both operations meet a time with strong cloud and haze-activity on the northern part of Mars. By comparing these images, my idea was to show the rapid change in cloud-structure. Due to the hidden surface it is not easy to identify landmarks, but I was able to locate some prominent craters for better orientation comparing the two images.

Processing colour from the original raw-frames by using the supplied flat-field, the atmospheric structures come out gray/white and not yellow/brown, so I assume they mainly are clouds and haze, not sandstorms. It is amazing how different these structures look, in some areas they look rather smooth, and in other areas they show very fine details. There also seems to be a difference between dawn and dusk, just compare the left (dusk) and right (dawn) terminator in the region of the “horn”. Also it seems that surface conditions affect cloud structure above. Processing these pictures was not easy and time consuming, but looking at the result I think time was not wasted. I do like this picture.”

Tech details

1 Our pictures taken 2010/11/13 were used:
10-317_00.33.20_VMC_Img_No_19.raw
10-317_00.34.03_VMC_Img_No_20.raw
10-317_00.34.46_VMC_Img_No_21.raw
10-317_00.35.29_VMC_Img_No_22.raw

The supplied dark frame “vmc_flat.raw” was used to extract png-files form the raw-material. Then we sharpened and stacked Pictures No 19/21 and 20/22 in order to reduce noise. The remaining noise was reduced further by utilizing Neat Image software. After cutting out the overexposed part of the stack 19/21 it was combined with the stack 20/22. The colour saturation was adjusted and the background was cleaned. Finally for better viewing the result was resized to 125%. For detailed information on processing see our work done with the astronomy group of Gymnasium Vaterstetten.
2 our pictures taken 2010/11/27 were used:

10-331_00.15.34_VMC_Img_No_19.raw
10-331_00.16.17_VMC_Img_No_20.raw
10-331_00.17.00_VMC_Img_No_21.raw
10-331_00.17.43_VMC_Img_No_22.raw

The supplied dark frame “vmc_flat.raw” was used to extract png-files form the raw-material. Then we sharpened and stacked Pictures No 19/21 and 20/22 in order to reduce noise. The remaining noise was reduced further by utilizing Neat Image software. After cutting out the overexposed part of the stack 19/21 it was combined with the stack 20/22. The colour saturation was adjusted and the background was cleaned. Finally for better viewing the result was resized to 125%. For detailed information on processing see our work done with the astronomy group of Gymnasium Vaterstetten.

3 For picture 2010/11/23 these pictures were used:

10-327_19.19.47_VMC_Img_No_19.raw
10-327_19.20.29_VMC_Img_No_20.raw
10-327_19.21.13_VMC_Img_No_21.raw
10-327_19.21.56_VMC_Img_No_22.raw

For picture 2010/11/27 these pictures were used:

10-331_00.15.34_VMC_Img_No_19.raw
10-331_00.16.17_VMC_Img_No_20.raw
10-331_00.17.00_VMC_Img_No_21.raw
10-331_00.17.43_VMC_Img_No_22.raw

Processing is sometimes not easy, and quite a bit of practice is helpful. Everybody may use his favourite software and try out what he can do with it. We use Photoshop, Giotto “Mexican Hat” for sharpening and Neat Image for noise reduction. Information on processing is found in the Gymnasium Vaterstetten report and on their astronomy homepage. Here I want to show the single steps I used processing the actual picture:

  •   Choose 2/2 high/low exposed frames, artefacts not same position
  •   Extract files by ”vmc2rgb.exe” utilizing flat-field “vmc_flat.raw”
  •   Sharpen all four pictures, a bit of noise is no problem
  •   Clean out known artefacts, do not alter same region in all frames
  •   Align carefully(!) and stack frames with same exposure time
  •   Place terminator-region from high exposed stack into low exposed stack
  •   Clean background using feathered selections
  •   Resize 125% and reduce noise with professional filter
  •   Adjust colour saturation carefully and moderately
  •   Split to luminance and colour, and reduce noise in colour only
  •   Make nice “fine tuning” but do not destroy original content

Remarks: We do not use the library-png because we want to see the colour of the raw-material and adjust it so that for example white clouds stay something ear white. We sharpen every single picture, doing this a bit of noise is no roblem because later two frames are stacked, and a professional noise filter s applied. Artefacts must be cleaned from each picture before stacking; hoosing pictures with artefacts not in the same place will preserves some riginal information for all parts. We align two frames in order to reduce oise, for this usually one image must be rotated a bit. We stack separately for igh and low exposure. Fitting the high exposure section to the low exposure icture is done by feathered selection and must be tried out very carefully.

Cleaning the background is done by a 2px feathered circle-selection very lose to the rim of Mars; then a 15-20px feathered oval selection is used at he terminator. This must be done carefully not to alter the original picture ore than necessary. If adjustment of colour saturation results in a bad colour oise, this may be reduced by applying a noise filter to the colour information nly (definitely not affecting the luminance). For this we separate luminance nd colour by Photoshop. At the end some 'fine-tuning' may be favourable for example feathered selection on a cloud patch to enhance white colour and o on). We do this carefully and moderately in order to preserve the original content of the picture.

 

Public Submission – Glowing North Pole by Mike Malaska

 

 

 

 

 

 

 

 

Regular VMC contributor Mike Malaska has submitted another outstanding image edit for the Mars Webcam blog, shown above. His work is based on an image of the North Pole of Mars from a VMC observation on the 30th September. The polar cap of the planet can just be seen in the middle of this image, with low sunlight glinting off the patches of snow and ice surrounding it. As Earth heads into Northern hemisphere autumn, Mars is also in Northern autumn at the moment and this view captures beautifully the impression of low sunlight in the Northern parts of Mars, with ice and snow signalling the coming winter.

Mike wrote the following to us about his work on this image:

"The main reason I initially got excited about this image was (1) North Pole of Mars and (2) taken at apoapsis (maximum height above Mars, about 10,000 km) of the Mars Express orbit. I was hoping for several pictures with very little change that could be used to make a 'super-resolution' image. Unfortunately, there was a 1-pixel-per-image rotation counter-clockwise (in this orientation) of the surface that messed up my plans.

This image was created by making an average of several images: Nos. 2, 4, 6, 8, 10, 12, 14, and 16, then Gaussian blurring this by 1 pixel to make a smooth color background. Next, Image No. 12 was used as a luminosity layer. It was also used as a HiPass layer to enhance subtle details. Finally it was blended with some of the original Image No. 12. Contrast enhancement and rotation (to put the North Pole at the top) and cropping gave the final image."

As always, excellent work Mike — and thank you for the submission and for showing us the beauty of Mars.

We'd love to see what other visitors can make of VMC images, too — just check out the Help us with VMC link at right to get started! -- Thomas

 

 

 

 

Haze in Valles Marineris by Peter Wellmann

We have an excellent submission to share with you as today's Friday treat: a poster project entitled 'Haze in Valles Marineris by Peter Wellmann'.

Peter has created a beautiful enhanced image and a poster highlighting atmospheric haze high above Valles Marineris; these are based on four VMC images acquired on 9 October 2008 (proving the point that archived data can have value years after it was collected) when Mars Express was orbiting about 7500 km above the surface.

Peter's first image shows a beautiful, long wispy streak of haze running over the entire Valles Marineris surface system - at more than 4000 km long, 200 km wide and 7 km deep, the Valles Marineris rift system is the largest-known canyon in the Solar System (and is much larger than North America's puny Grand Canyon). His poster includes many additional details of surface geography and clouds.

We were really impressed with the analysis that Peter did prior to starting image enhancement work - which was a challenge due to the considerable amount of movement by Mars Express during the 3.5-minute slot in which the four raw images were acquired. This work follows on Peter's earlier submission, North polar cap - posters by Peter Wellmann, posted on 18 August.

Thanks, Peter, for an excellent submission! (Click on 'Full story' to access more details and the full-size versions of the images). -- Daniel Scuka

The original Mars Webcam images (Nos. 3, 4, 5 and 7) can be found in the 9.10.2008 set here.

First, here are Peter's two images (his explanatory text is below).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Peter writes:

"The picture of Valles Marineris: About 7500 km out from Mars, Mars Express VMC shot a sequence of pictures showing interesting details. The whole system of Valles Marineris is drowned in a white haze. The large crater to the right seems to be Lowell crater, hiding its interesting inner ring-feature below haze. Originating from Arsia Mons a large cloud is visible that is getting lost in the dark of the terminator.

Viewing the raw-material from 2008/10/09, we had the idea that the hazy patch seen at the terminator in the region of Arsia Mons could be some kind of reflection, but studying the other frames of the sequence showed that this rather is a true structure on Mars. Reaching into the dark of the terminator, it must be high above the ground - probably a large cloud originating near Arsia Mons.

For processing it was decided to use four raw frames to reduce noise, taking into account that this would not deliver a perfect result due to the considerable movement of Mars Express during the 3.5 minutes slot the pictures were taken.

•      08-283_04.27.15_VMC_Img_No_3 ('red' image)
•      08-283_04.28.08_VMC_Img_No_4 ('blue' image)
•      08-283_04.29.01_VMC_Img_No_5 ('blue' image)
•      08-283_04.30.47_VMC_Img_No_7 ('red' image)

Using vmc_flat.raw flatfield and vmc2rgb.exe tools, the pictures were converted from .raw to .png files. The VMC flatfield works fine - at the time being there is only one larger defect that is not corrected sufficiently. After resizing to 150 percent, the two red and blue pictures were stacked. After cutting out the overexposed part with a feathered selection, the blue result was stacked to the red result with 60% transparency. As expected, the rapid movement of Mars Express became a problem, we could not find a perfect fit for the stacked frames. Having no special (and expensive) software for this purpose, we adjusted this sufficiently for a medium quality result only. The final picture was sharpened with a Mexican Hat filter, then high frequency noise was reduced with the software Neat Image, sacrificing some sharpness again.

Finally, Photoshop was used to give the picture the 'final touch" by carefully removing known artifacts of VMC, adjusting levels and colour saturation and cleaning the dark background of the picture. When adjusting levels and colour, a mask for white with a tolerance of 60 and feathered edges of 3 pixels was used to emphasize the hazy area of Valles Marineris."

Thanks Peter!

School report: Mars Webcam Project by Gymnasium Vaterstetten

 

We are delighted today to bring you a detailed post on the excellent Mars Webcam project submitted by the Astronomy Group at the Humboldt Gymnasium (high school) in Vaterstetten, near Munich, Germany. The project began in March 2010, when the school's Astronomy Group, led by teacher Markus Schmidtner, set forth the following project goal:

The astronomy group of the grammar school in Vaterstetten, Germany, was happy to get the opportunity to adopt a VMC-Operation. This operation took place on 23rd of March 21 from 0:28 a.m. to 1:08 a.m. At this moment the satellite was situated near the apocenter of the orbit, the highest altitude above the planet. The aim was to process the raw - images supplied by ESA and then compare the images taken with the Visual-Monitoring-Camera (VMC) with our own telescope images and to generate a stereo image with the data of the VMC.

Our post today includes several of the excellent images processed and developed by the school team as well as links to their full PDF & web report.

"Speaking on behalf of the entire Mars Express Flight Control Team, I am very impressed with the work done by the teachers and students at the Humboldt Gymnasium. Their work, analysis and results prove the value both educational and scientific of even 'low-tech' images delivered from deep space. Congratulations on a project well done and we wish you continued success in your studies."

-- ESA's Michel Denis, Mars Express Spacecraft Operations Manager, ESA/ESO

All of us here at the Mars Webcam blog were tremendously impressed with the work done by the students. The goal was to analyse VMC images and determine how these compare in resolution to images obtained from the ground and, interestingly, from the joint ESA-NASA Hubble Space Telescope.

The student team was able to demonstrate that the VMC camera, viewing Mars from 10 000 km, provides images having similar resolution to those provided by the Hubble telescope viewing Mars at 88 million km. They also created an excellent stereo image of Mars.

Congratulations and thanks for an excellent report!

"When Mars Express leaves apocenter and approaches the Planet, resolution of VMC images will increase so much that even the powerful Hubble Telescope has no chance - this shows drastically the importance of missions like Mars Express. If you want to find out, you must go there..."

-- Humboldt Gymnasium VMC Project Report

Scroll down to access several sets of content submitted by the students at Humboldt Gymnasium.

1. Image gallery - student processed images

A gallery of images processed and analysed by the students. These are based on the original raw VMC image set acquired 21 March 2010.

Of these, the two below are especially well done:

2. Project report - web version (condensed)
Access the school's online project report via http://www.gym-vaterstetten.de/faecher/astro/ESA_Projekt/esa.htm. The report includes images and text detailing their goals, processes and learnings during the project.

 

 

 

 

 

 

 

 

 

 

Animation & comparison: two excellent creations based on Mars Webcam images

Long-time VMC supporter Emily Lakdawalla at the Planetary Society has created an excellent animation from the image set acquired 8 August by Mars Express as it soared over the Red Planet's northern ice cap.

Emily writes:

 Yesterday, I found a really nice set that I just had to animate, taken from a relatively low altitude over the picturesque swirls of Mars' north polar cap, which is brightly lit now by round-the-clock summer sun. This animation is composed of 23 photos taken by the 'Mars Webcam' aboard Mars Express, spanning a little more than half an hour on August 9, 2010. During the animation, Mars Express recedes from an altitude of about 4100 kilometers to about 7000 kilometers above the planet. The twisted canyons of Mars' north polar cap occupy the center of the view. Click here for a version at the camera's full resolution.

We were delighted to see such a quick and well-done response to this image set - good work and thanks, Emily!

Another long-time friend of the VMC, Mike Malaska, also posted a very nice comparison between two VMC images taken some six weeks apart, on 27 May and 8 August.

Mike wrote:

"The north pole is at center in the two images, the 300 longitude line is approximately at top. Large differences in ice cover can be seen near Chasma Boreale (the deep chasm at lower center). The triangle shaped region at upper right is Olympia Mensae. Interestingly, while the August 8th image generally seems to have more ice overall, the region just poleward of Olympia Undae (which is the darker region poleward of Olympia Mensae) seems less ice covered than in the May 27th image."

Well done, Mike - and thanks to you also!

With two strong creations based on the excellent 8 August VMC image set, we thought it would be interesting to provide some background info on how the Mars Webcam acquired these frosty polar pictures. Hannes Griebel, Mars Express Spacecraft Operations Engineer and multiple past contributor to our VMC Blog, works on the mission planning system, and he provided this description.

Mars Express primary scientific observations are always prioritised ahead of VMC operations. This usually leaves only small VMC picture-taking opportunities at the maximum distance from Mars (apocentre), since conditions at this point in the the spacecraft's orbit are often not usable for science operations (due to the large distance to the planet and firings from the Mars Express thrusters). Occasionally, an observation slot is available at a lower altitude, allowing VMC to operate much closer to the planet and take spectacular, and for such a simple device, quite detailed, images - such as the recent polar images from 8 August. When such a slot occurs, the Mars Express Flight Control Team at ESOC do all they can to make the most of the opportunity, while still maintaining the primary science operations required by the Mars Express mission.

Images from any VMC observation, routine or special, are uploaded and made available via the VMC Blog immediately after they are received on the ground from Mars Express. However, their real potential is often revealed only after members of the public turn them into stunning compositions and animations - which we are delighted to receive and share via posting in the VMC Blog from here at ESOC! If you want to submit any work based on raw VMC image sets - be it processed images, animations, a poem, an artistic interpretation, an analysis of the image content or (more or less) anything else - then please feel free to contact us (you can find more details under Help us with VMC in the links to the right of this page).

Thanks, Hannes, for this background report - and from all of us on the VMC team, thanks to everyone who has submitted results to the VMC Blog.

Keep up the great work!

-- Daniel Scuka

 

 

 

 

 

 

 

 

 

North polar cap – posters by Peter Wellmann

 

Peter Wellmann, from Germany, has sent in two excellent Mars poster compositions using the fabulous 8 August polar cap image set.

His first poster comprises a cleverly processed main image (based on two of the raw VMC images) and several smaller images to provide location and orientation information. Peter has also included a detailed identification and description of craters, possible dust clouds and the day-night terminator. The second poster shows the original processed image in a larger size.

Peter wrote:

 "On the way out to apocenter, Mars Express VMC shot this wonderful picture of the South Polar Cap emerging from the dark terminator above. Composed of two RAW-frames it shows fine colour shades and a lot of small craters not readily seen in the single frames. The lower left might show some dust, clouds or haze, the bottom right corner shows bright patches in the region of Moreux crater we suggest to be clouds."

Access Peter's full report and full-size versions of his images under 'Full story below'. Thanks, Peter, for an excellent submission! -- Daniel

Here is Peter's second poster (click either image in this post to access the original, largest, size):

Peter writes:

Seeing the raw-material from 2010/08/08, I just had to give it a try. I decided to use two raw frames to reduce noise, and to utilize the whole area of both pictures instead of selections only for better noise reduction. After resizing to 150 percent and sharpening with a Mexican Hat filter, the two frames where ready for combining them:

•     10_220_23.51.39_VMC_Img_No_3_rgb
•     10_220_23.52.21_VMC_Img_No_4_rgb

The problem is, that due to rapid movement of Mars Express, the two frames would not fit together. So Photoshop layer distortion was used to adapt one of the pictures exactly to the other, not an easy task. I accomplished sufficiently by 'blinking' from one frame to the other, until blinking would not move the structures seen in the images. Then the upper layer was set to 50 percent transmission and then the two layers were reduced to one. Additional reduction of high frequency noise was done with the software Neat Image, to manage this without destroying to much sharpness is quit a demanding task.

Finally Photoshop was used to give the picture the 'final touch' by carefully removing the known artifacts of VMC, adjusting levels and colour saturation and cutting the edges of the picture. When adjusting levels and colour a mask for white with a tolerance of 100 and feathered edges of 30 pixels was used to protect the snowy areas of the Polar Cap in order to preserve the white colour.

Peter also wrote: "I am very grateful to ESA for supplying material for public processing, I had a lot of fun procession this material."

Thanks for a great job! -- DGS

Editor's note: Peter is also lending his image-processing expertise to students at a high school near Munich, who are working on a school VMC project. We look forward to publishing their work shortly.