Geology topics

A.T. Young

Publications and source records attributed to A.T. Young.

3 recordsLinked to original sources

USGS1973

Mariner 9-Image processing and products

The purpose of this paper is to describe the system for the display, processing, and production of image-data products created to support the Mariner 9 Television Experiment. Of necessity, the system was large in order to respond to the needs of a large team of scientists with a broad scope of experimental objectives. The desire to generate processed data products as rapidly as possible to take advantage of adaptive planning during the mission, coupled with the complexities introduced by the nature of the vidicon camera, greatly increased the scale of the ground-image processing effort. This paper describes the systems that carried out the processes and delivered the products necessary for real-time and near-real-time analyses. References are made to the computer algorithms used for the, different levels of decalibration and analysis.

Icarus↗

USGS1972

The martian atmosphere: Mariner 9 television experiment progress report

Atmospheric phenomena appearing in the Mariner 9 television pictures are discussed in detail. The surface of the planet was heavily obscured by a global dust storm during the first month in orbit. Brightness data during this period can be fitted by a semi-infinite scattering and absorbing atmosphere model with a single-scattering albedo in the range 0.70–0.85. This low value suggests that the mean radius of the particles responsible for the obscuration was at least 10 μm. By the end of the second month, this dust storm had largely dissipated, leaving a residual optical depth ∼0.1. Much of the region north of 45°N was covered by variable clouds comprising the north polar hood. The cloud structures revealed extensive systems of lee waves generated by west-to-east flow over irregular terrain. Extensive cloud systems in this region resembled baroclinic wave cyclones. Clouds were also observed over several of the large calderas; these clouds are believed to contain water ice. Several localized dust storms were seen after the global dust storm cleared. These dust clouds appeared to be intensely convective. The convective nature of these storms and the stirring of large dust particles to great heights can be explained by vertical velocities generated by the absorption of solar radiation by the dusty atmosphere.

Icarus↗

USGS1972

Imaging experiment: The Viking Lander

The Viking Lander Imaging System will consist of two identical facsimile cameras. Each camera has a high-resolution mode with an instantaneous field of view of 0.04°, and survey and color modes with instantaneous fields of view of 0.12°. Cameras are positioned one meter apart to provide stereoscopic coverage of the near-field. The Imaging Experiment will provide important information about the morphology, composition, and origin of the Martian surface and atmospheric features. In addition, lander pictures will provide supporting information for other experiments in biology, organic chemistry, meteorology, and physical properties.

Icarus↗