Wavelength: Objectives: Determine which chemicals sunphotometer should recognize Research spectra of chemicals of interest Investigate necessary abilities of CCD array Investigate alternative designs of sunphotometer
Important Elements of the Martian Atmosphere Atmospheric composition (by volume): Major : Carbon Dioxide (CO2) - 95.32% ; Nitrogen (N2) - 2.7% Argon (Ar) - 1.6%; Oxygen (O2) - 0.13%; Carbon Monoxide (CO) - 0.08% Minor (ppm): Water (H2O) - 210; Nitrogen Oxide (NO) - 100; Neon (Ne) - 2.5; Hydrogen-Deuterium-Oxygen (HDO) - 0.85; Krypton (Kr) - 0.3; Xenon (Xe) - 0.08
Past Experimentation Whiting- Determination of Mars Atmospheric Composition
The Right Tool for the Job Expected spectra and conditions on mars will determine the necessary attributes of a CCD array for the sunphotometer The array must meet conditions for: pixel size light sensitivity operating conditions physical size and accuracy Array should be lightweight, durable, and draw as little power as possible
Other Design Possibilities Another possibility for a hemispherical viewing devise might be a reflecting cone.
Initial Parameters Entrance Aperture of 2.00 mm Ray angle range from zenith 18-89 degrees
Winston Cone Equations = Winston Cone Equation in (r, z) coordinates: Inverting the Equation: Dimension equation: =
Dimensions Entrance Aperture radius: 1.00 mm Exit Aperture radius: 3.236 mm Cone Height: 13.037 mm Focal Length: 1.309 mm Note: All dimensions are based on 2.00 mm aperture size and 18 degrees off the zenith inclination.
Concerns Size of Cone Manufacturing Interface (CCD)
Dispersion Technique Matt and Chris C. have just been assigned to this task.
CCD 2-D array is chosen as the incident light moves across the sky, the dispersed spectrum moves across the array area. Using the determined wavelength spectra, the CCD material will be determined.