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T.B. McCord,
J.B. Adams,
G. Belucci,
J.-P. Combe,
A.R. Gillespie,
G. Hansen,
H. Hoffmann,
R. Jaumann,
G. Neukum,
P. Pinet,
F. Poulet, K. Stephan
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ABSTRACT: The High Resolution Stereo Camera (HRSC) on the Mars Express (MEx) spacecraft in orbit about Mars is delivering images of the Mars surface and atmosphere from its high-inclination, elliptical orbit that are intended to cover most of the Mars surface by the end of the mission. These are acquired in four specific spectral passbands that sample the scene at different parts of the extended visual spectrum from near 0.4 μm to about 1μm and in five additional channels, four used for stereo and one nadir, that use the same fifth spectral passband. These channels view from different angles and can be used for photometric and spectral analysis. The data allow a variety of studies of the surface and atmosphere of Mars, but these require detailed understanding of the data characteristics, as there are several effects, including of the observation geometry and the atmosphere, that need to be treated. This article is a report to the science community on the current understanding of the HRSC color data after an initial analysis and also a demonstration of their capabilities for study of Mars, which, from this study, appear to be considerable. We first discuss the characteristics and calibration of the HRSC spectral data. The atmospheric influence on the photometric appearance of the surface materials is explored, and methods of compensating are considered. Reflectances are calculated for surface units by assuming the dark material is basalt and scaling the entire HRSC scene using a laboratory basalt spectrum for the selected dark material area; the results and the correction factors for different orbits are compared. We present several examples of what could become a large volume of future science results utilizing the HRSC spectrophotometric data in conjunction with photo-interpretation. For example, we find relatively few but very important distinct spectral components at the HRSC resolution, including what we interpret as iron oxide-rich material, unoxidized basalt, and polar ice, consistent with past works. The major spectral components are distributed in ways that suggest compositional mixing and the need to revise the current geologic understanding of major regions.
Journal of Geophysical Research. 112(2007-06-16-E06004).
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AGU Fall Meeting, San Francisco, 1317 December 2004;
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R. Jaumann,
G. Neukum,
T. Behnke,
T. C. Duxbury,
K. Eichentopf,
J. Flohrer,
S. van Gasselt,
B. Giese,
K. Gwinner,
E. Hauber, [......],
R. Pischel,
D. Reiss,
E. Ress,
T. Roatsch,
P. Saiger,
F. Scholten,
Gottfried Schwarz, K. Stephan,
M. Wählisch,
HRSC Co-Investigator Team
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ABSTRACT: ESA's Mars Express has successfully completed its nominal mission of one Martian year covering about 25% of the surface in stereo and color with resolutions up to 10 m/pixel by its high-resolution stereo camera (HRSC). Mars Express is now in its extended mission phase, during which much of the remaining part of the Martian surface is envisaged to be covered in stereo and color. The HRSC instrument is designed to map the morphology, topography, structure and geologic context of the surface as well as atmospheric phenomena. This paper discusses the measurement principles and operations of the instrument as well as the acquisition, calibration and processing of regional and global data sets. As HRSC is a push-broom scanning instrument with nine CCD line detectors mounted in parallel on a focal plane, its unique feature is the ability to obtain near-simultaneous imaging data at high resolution, with along-track triple stereo, four colors and five different phase angles, avoiding any time-dependent variations of the observing conditions. The HRSC spatial resolution is 10 m/pixel at the nominal periapsis altitude of 250 km, with an image swath of 53 km, and 2.3 m/pixel for an additional framing CCD device, called super resolution channel (SRC), practically working as an additional tenth channel of the HRSC and yielding nested-in black and white images for studies of small-scale geologic features. The sub-pixel accuracy of the three-dimensional point determination allows the derivation of digital terrain models (DTMs) with a grid size of up to 50 m and a height accuracy of a single pixel with up to 10 m, thus enabling us to carry out detailed quantitative analyses of the surface structure. The HRSC (1) bridges the gap between the medium–high-resolution Viking imagery and the very-high-resolution Global Surveyor mission, thus providing geological context, and (2) fills the gaps in the three-dimensional coverage and DTM grid of the MOLA laser altimetry data, and (3) helps characterize landing sites for in-situ measurements. HRSC also builds the basis for extended compositional mapping when combining spectral information with topographic photomaps over large areas. So far the HRSC measurements have made a significant contribution to the study of the evolution of volcanism and the role of water and ice throughout the Martian history.
Planetary and Space Science 55(2007-7-8):928-952. · 2.22 Impact Factor
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R. Jaumann, K. Stephan,
F. Poulet,
D. Tirsch,
R. Wagner,
H. Hoffmann,
D. Reiss,
E. Hauber,
J. P. Bibring,
G. Neukum,
HRSC Co-Investigator Team
XXXVII Lunar and Planetary Science Conference;
