Ecco una immagine a più alta risoluzione ripresa dalla MOC (Mars Orbiter Camera) installata a bordo della Mars Global Surveyor.
Ed ecco i dati della ripresa e delle elaborazioni:
CYDONIA OBSERVATION #3 PHOTO CAPTION
Orbit: 258
Range: 409.53 km
Resolution: 3.46 m/pixel
Image dimensions: 1024 X 9600 pixels, 3.5 km x 33.2 km
Line time: 0.50 msec
Emission angle: 29.90 degrees
Incidence angle: 69.59 degrees
Phase angle: 60.62 degrees
Scan rate: ~0.15 degree/sec
Start time: periapsis + 410 sec
Sequence submitted to JPL: Wed 04/22/98 21:45:00 PDT
Image acquired by MOC: Thu 04/23/98 12:23:02 PDT
Data retrieved from JPL: Fri 04/24/98 09:00 PDT
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Processing Performed by Tim J. Parker, Geologist
Mars Pathfinder Science Support, JPL.
Image Processing Steps:
(1) Vertical banding in raw image removed using Vicar software with long,
narrow, highpass box filter, oriented parallel to banding in image.
(2) Performed moderate histogram stretch in Adobe Photoshop on
Macintosh desktop computer.
(3) "Flattened" broad shading variations in scene by
copying image and creating a "mask" in Photoshop with
the shading inverted with respect to the original image. This mask
was then merged with original scene and a second histogram stretch perf
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Processing Performed by MIPL, JPL
Image Processing Steps:
(1) The image is sized down by interpolation by a factor of two to
reduce some of the noise.
(2) A long, narrow high-pass filter is applied in a vertical orientation
to help reduce some of the instrument signature. This signature is seen
as the streaking that is noticeable in the original data.
(3) A long, narrow low-pass filter is applied in a horizontal orientation
to create an intensity average for the image.
(4) The results of these filtering operations are the stretched to
approximate a Gaussian distribution.
(5) The results of the high-pass and low-pass processing steps are
averaged together to form the final product.