Atmospheric volume emission tomography from a satellite platform
Degenstein, Douglas Arthur
It is extremely important for current atmospheric modeling efforts that the two and three dimensional structure of the atmospheric constituents be known. It is equally important that these constituent profiles be known globally with high temporal resolution. Optical instruments onboard satellite platforms can provide measurements that make this knowledge possible. This work presents a tomographic technique to use line of sight brightness measurements of the atmosphere made by an orbiting optical instrument to determine the two dimensional volume emission profile that has been remotely sensed. The basic technique was originally developed to deblur Fabry-Perot images and is closely related to the processes used in medical imaging. Although the tomographic technique was originally developed as a statistical analysis it is shown that it is the viewing geometry that is the fundamental characteristic with respect to algorithm performance. Further, it is shown that the tomographic technique is capable of resolving structures in the atmospheric volume emission profile that are as small as 300 km along the satellite track with I km vertical resolution. It is found that this holds for a wide range of realistic operational conditions that include significant observational noise. The Swedish based Odin spacecraft scheduled for launch in early 2000, will fly in a sun-synchronous dusk-dawn orbit and will include the Canadian OSIRIS instrument. OSIRIS is able to measure the oxygen infrared atmospheric bond simultaneously at multiple tangent altitudes at two separate wavelengths. These measurements am related to the mesospheric ozone profile and are ideal inputs for the tomographic technique. It is shown that there is no degradation in the algorithm performance even though the oxygen infrared atmospheric bond emissions are absorbed.