HR: 0800h
AN: P41A-0915    [Abstracts]
TI: A Sunphotometer for Mars Atmosphere Studies
AU: * Strawa, A W
EM: Anthony.W.Strawa@nasa.gov
AF: NASA-Ames Research Center, Mail Stop 245-4, Moffett Field, CA 94035 United States
AU: Velante, M
EM: mbvelante@yahoo.com
AF: San Jose State University, Department of Mechanical and Aerospace Engineering One Washington Square, San Jose, CA 95192 United States
AU: Colaprete, A
EM: tonyc@freeze.arc.nasa.gov
AF: NASA-Ames Research Center, Mail Stop 245-4, Moffett Field, CA 94035 United States
AU: Papadopoulos, P
EM: ppapado1@email.sjsu.edu
AF: San Jose State University, Department of Mechanical and Aerospace Engineering One Washington Square, San Jose, CA 95192 United States
AB: The interaction between the sun's energy and Martian dust is recognized as one of the biggest driving forces for climate on Mars, yet not enough is known about the physical and optical properties of this dust or its spatial and temporal variation. A better understanding of the interaction between Mars dust and its weather and climate is required for manned exploration. Recognizing this, we are developing an instrument concept that would enable dedicated measurements to characterize Mars' atmosphere and dust than has been possible in the past. The instrument is based on the sunphotometer concept, integrating concepts that produce an instrument with no moving parts. Consequently, it would be small, light weight, and consume little electrical power. Sunphotometer's are commonly used on the Earth's surface, as well as on aircraft, to determine the solar energy attenuated by gases and aerosol particles in the atmosphere. Typically, these instruments track the sun to measure the direct solar attenuation. Our concept uses a combination of unique optics and a detector array to eliminate the moving parts and make the instrument much smaller, compact, and reliable. Data products would include downwelling flux, gas and aerosol optical depth at multiple-wavelengths, gas phase constituent column density, and aerosol size distribution. One of the desirable features of this concept is that the techniques exist that would enable the instrument to be self-calibrating throughout the year. This means that as dust begins to deposit on the instrument window, or the electronics or sensor array degrade, the instrument could be periodically recalibrated in situ. Thus it would provide invaluable data for long-term modeling efforts. This system would also be able to compensate for deployment on non-level surfaces. This instrument would have applicability to the Discovery and Mars Exploration class Missions. The instrument would be a valuable component in the exploration of any planetary body with an atmosphere, for example Titan. As part of this project we have sought to involve graduate and undergraduate students at San Jose State University. This paper will discuss the instrument design concept and present proof of concept experiments that have been conducted.
DE: 6213 Dust
DE: 6225 Mars
DE: 6297 Instruments and techniques
SC: Planetary Sciences [P]
MN: Fall Meeting 2005