Image Sets  03 August, 2009 20:42

New Images From 03 August 2009 Added

09-215_20.14.12_VMC_Img_No_1.pngNew images have been posted to the image database. These images are from the VMC observation on 03 August 2009. To access the images click the link below. Also you can access the Celestia file to see where the images were captured and access the raw data in the zip file (for more details see Help us with the VMC)



03/08/2009 20:14-20:42 Gallery

Celestia Script

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General  03 August, 2009 11:53

ESA's Mars Webcam and the Real Science it Produces - repost

In SciLogs, Michael Khan writes:

This free service to the worldwide community of amateur Mars aficionados has led to considerable interest and impressive results. Obviously, the VMC image quality does not even remotely resemble that of a "real" imaging science instrument like the HRSC on MEX or the HiRise on MRO.

But we should not forget that the VMC images are still far better than anything available even to professional astronomers until the first space probes reached Mars, starting with Mariner 4 less than 45 years ago. No wonder an active community has formed that competes for the best image to extracted from the available raw material.

Read the full text of Michael's post here.

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   Slideshow
Public submission by Martin Ahr: I have created an animation from a VMC image series that was made on November 5, 2009. It shows what I believe to be clouds onto which the sun starts shining as the rotation of Mars brings them towards the sunlit side. There are clouds which appear to move also in a direction transverse to the direction of rotation of Mars, and some seem to disappear as the sun starts shining on them. For each frame of the animation, I combined three images from one of the exposure bracketing series into one HDR image. I tried to also use the fourth image having the shortest exposure time. However, the HDR program I used could not combine this image with the other three images, probably because the difference in brightness between the image and the other three images is very large. Since the sunlit side of Mars is overexposed in all three images used, it remains overexposed. However, the dynamic range of the HDR image is sufficient to cover the entire brightness range of the clouds. I then took the logarithm of the brightness values of the pixels in each HDR image to obtain images that can be displayed on a monitor while still showing the full dynamic range of the HDR images. Thereafter, I shifted the images such that Mars it at substantially the same position in each image, combined the images into an animation and rotated the animation such that the sunlight shines from the right. I tried several orientations, and, in my opinion, this one looks most natural. Unfortunately, Mars is moving out of the camera's field of view at the end of the series. Since the clouds are not shown any more in images No. 30 and later, I omitted these images. In the remaining images, I made the cut off portions transparent (which can be seen in the animation at the upper right part of Mars). GIF images can comprise only 256 different colors. Therefore, I converted the images to grayscale. This does not make much difference, since the color saturation in the original images is so low that colors are almost invisible. I used three computer programs for the processing: Fitswork for reading the raw data, extracting color information from Bayer patterns, shifting images and calculating logarithms of brightness values; FDRTools Basic for creating HDR images; and Gimp for combining the images into an animation, minor adjustment of the brightness of individual images and rotating the animation. This is a list of the VMC images used for the animation: Frame 1: 09-309_19.02.06_VMC_Img_No_3.raw,09-309_19.02.59_VMC_Img_No_4.raw,09-309_19.03.53_VMC_Img_No_5.raw; Frame 2: 09-309_19.05.39_VMC_Img_No_7.raw,09-309_19.06.33_VMC_Img_No_8.raw,09-309_19.07.26_VMC_Img_No_9.raw; Frame 3: 09-309_19.09.13_VMC_Img_No_11.raw,09-309_19.10.06_VMC_Img_No_12.raw,09-309_19.10.59_VMC_Img_No_13.raw; Frame 4: 09-309_19.12.46_VMC_Img_No_15.raw,09-309_19.13.39_VMC_Img_No_16.raw,09-309_19.14.33_VMC_Img_No_17.raw; Frame 5: 09-309_19.16.19_VMC_Img_No_19.raw,09-309_19.17.13_VMC_Img_No_20.raw,09-309_19.18.06_VMC_Img_No_21.raw; Frame 6: 09-309_19.19.53_VMC_Img_No_23.raw,09-309_19.20.46_VMC_Img_No_24.raw,09-309_19.21.39_VMC_Img_No_25.raw; Frame 7: 09-309_19.23.26_VMC_Img_No_27.raw,09-309_19.24.19_VMC_Img_No_28.raw,09-309_19.25.13_VMC_Img_No_29.raw. Image Credit: Martin Ahr, ESA Credit: ESA/Peter Wellmann Dec 23 2009 MEX-VMC Composite of Valles Marineris and Argyre Planitia ---- Composite image of MEX-VMC images taken on December 23, 2009. ---- The raw images were then converted to rgb.png files using Gordan Ugarkovic's VMC2RGB utility with flatfield correction. MEX-VMC Images No 11, 15, 19, and 24 were coordinated to Image No 19. The set was converted to 16-bit, then increased in size 5x. All the images werecontrast-adjusted to image no 24. Layer masks were used to blend the mosaic. The final image is a HiPassLRGB composite. ---- To make the RGB Color layer, a Hue/Saturation level was added (+40) and a Channel Mix layer was added (R: +170%Red, -50%Green, -20%Blue; G: -20%Red, +140%Green, -20%Blue; B: -50%Red, -20%Green, +170% Blue). The color image was Gaussian Blurred 1.5 pixels. ---- To make the luminance (L) layer, the unblurred color layer was converted using a B&W conversion layer with R:+60%,Y:+70%,G:+70%, C:+20%, B: +50%, M: +50%). The luminance layer was combined in the stack with the Luminance blending mode. Above this was placed another B&W converted layer, this time with a 30 pixel HiPass filter that was blended with the other layers in the stack. A final Curves layer were added to make the final composite. ---- The combined image was then downsampled to 100% and rotated so that north is at top. ---- In the image, Valles Marineris and Eos Chaos can be seen at top center. At the extreme south of the composite, the bright Argyre Planitia can be seen. ---- Image credits: ESA / Mike Malaska ---- Original via: http://www.flickr.com/photos/31678681@N07/4230483496/ Doug Ellison: Mars Limb Mosaic, 15th December 2010. I used ugordan's VMC2RGB app to convert the .raw VMC files into .png images. Then I used Photoshop to enhance the colour saturation and mosaic the frames. Image credits: Doug Ellison/ESA Mars image in false colour created from two originals captured 10 October 2008. The originals were processed by Bogdan Stancescu, Bucharest, Romania. Bogdan writes: