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Safaeinili, A.

Publications and source records attributed to Safaeinili, A..

32 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS2001

The System and Implementation Aspects of the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS)

MARSIS is a radar sounder operating in the HF frequency range to sound the surface of Mars, which will operate from the ESA Mars Express spacecraft. It is scheduled for launch from Baikonour, Russia in June 2003 and arrives in orbit around Mars in early 2004 for a two-year mission. This system is the result of an international collaboration between NASA, the Italian Space Agency (ASI), and European Space Agency (ESA). The MARSIS instrument is a 17 Kilogram total mass sounder consisting of a 40 meter tip-to-tip dipole antenna, a 7 meter long monopole antenna and the electronics module. This design of MARSIS is a tradeoff between the expected penetration into the Martian subsurface that is proportional to the wavelength of the system and the desire to operate at a short wavelength in order to minimize the effects of the ionosphere. Additional information is contained in the original extended abstract.

Jordan, R.↗
NASA NTRS2001

Subsurface Sounding of Mars: The Effects of Surface Roughness

The Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) will conduct a global survey of Mars from the Mars Express Orbiter starting in 2004. The primary objective of the subsurface observations is to detect material interfaces in the upper several kilometers of the crust of Mars, with a particular emphasis on mapping the 3D distribution of water and ice in that portion of the crust. In order to detect subsurface interfaces, the returned echo from the subsurface must be distinguished from noise and clutter, which can arise from a variety of sources. One source of clutter is surface topography that generates backscattered energy at the same time delay as the subsurface region of interest. Surface topography can affect the detectability of subsurface features in several other ways. Surface roughness at scales comparable or somewhat smaller than the radar wavelength reduces the coherency of the wave as it passes the upper interface. Also, surface slope (tilt) at scales of the radar footprint and larger (> 5 km) affects the apparent Doppler signature of the echoes, and effectively disperses the wave transmitted into the subsurface, making processing and interpretation difficult. In this paper, we report on the roughness characteristics of Mars at these various scales as measured by the Mars Global Surveyor Laser Altimeter (MOLA), and consider the implications for achieving the subsurface sounding goals of MARSIS. Additional information is contained in the original extended abstract.

Plaut, J. J.↗
NASA NTRS2000

Low Frequency Rada Sounding Through Martian Ionosphere

In remote radar sounding, it is highly desirable to operate at low frequencies to improve depth of penetration. For spaceborne sounders, the lowest operating frequency is limited by the effect of the ionosphere due to significant dispersion of the radar waves at near plasma frequency.

Radar Sounder Ionosphere Mars Ionospheric Dispersi↗
NASA NTRS2000

A New Coherent Radar for Ice Sounding in Greenland

This paper will discuss a new multifrequency dual channel coherent radar depth sounder for sounding ice. This sounder is unique since it is a fully coherent chirp radar design to operate at low (1500') as well as high altitudes (30,000').

radar↗