The Scanning Imaging Absorption Spectrometer for Atmospheric Chartography instrument (SCIAMACHY) instrument exhibits useful observational abilities to separate meteoric metal total content within different levels of the atmosphere. In this work, we present an algorithm to give the total content and to separate the total column into two partial columns in the thermosphere and the mesosphere, using measurements of resonant radiation by the SCIAMACHY instrument. Limb and nadir measurements are used. The results presented here constitute the first simultaneous measurements of mesospheric and thermospheric column densities including the successful separation of same. We present column density measurements of Mg II and Mg I in the mesosphere and the thermosphere and the total content. The data set considered here covers the latitude range from 80°S to 80°N and covers the time range from 2002 to 2006. Measurements are taken on a global scale to investigate seasonal and spatial variations. Total columns range from 10⁷ to 10¹⁰ cm⁻², in good agreement with previous satellite measurements and model calculations. The temporal evolution of both Mg I species is investigated over the time range from mid‐2002 until the end of 2006. A pronounced minimum in 2003 and a subsequent increase until 2006 are observed for the ionized species. The global distribution of both Mg I and Mg II is found to be seasonally varying, exhibiting maximum column densities within the summer hemisphere. No significant correlation with the solar activity is found. Increased abundances of Mg II are observed within regions of high geomagnetic activity (i.e., the northern and southern auroral ovals) only if the background abundance of Mg II is low. It is concluded that the increase of Mg II due to particle impact is a minor effect.

We present a numerical illumination model to calculate direct as well as diffuse or Hapke scattered radiation scenarios on arbitrary planetary surfaces. This includes small body surfaces such as main belt asteroids as well as e.g., the lunar surface. The model is based on the ray tracing method. This method is not restricted to spherical or ellipsoidal shapes but digital terrain data of arbitrary spatial resolution can be fed into the model. Solar radiation is the source of direct radiation, wavelength-dependent effects (e.g. albedo) can be accounted for. Mutual illumination of individual bodies in implemented (e.g. in binary or multiple systems) as well as self-illumination (e.g. crater floors by crater walls) by diffuse or Hapke radiation. The model is validated by statistical methods. A ${\chi }^2$ test is utilized to compare simulated images with DAWN images acquired during the survey phase at small body 4 Vesta and to successfully prove its validity.

We present a numerical illumination model to calculate direct as well as diffuse or Hapke scattered radiation scenarios on arbitrary planetary surfaces. This includes small body surfaces such as main belt asteroids as well as e.g. the lunar surface. The model is based on the raytracing method. This method is not restricted to spherical or ellipsiodal shapes but digital terrain data of arbitrary spatial resolution can be fed into the model. Solar radiation is the source of direct radiation, wavelength-dependent effects (e.g. albedo) can be accounted for. Mutual illumination of individual bodies in implemented (e.g. in binary or multiple systems) as well as self-illumination (e.g. crater floors by crater walls) by diffuse or Hapke radiation. The model is validated by statistical methods. A χ2 test is undertaken to compare simnulated images with DAWN images acquired during the survey phase at small body 4 Vesta.