Physics – Optics
Scientific paper
Apr 2003
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003eaeja....14285h&link_type=abstract
EGS - AGU - EUG Joint Assembly, Abstracts from the meeting held in Nice, France, 6 - 11 April 2003, abstract #14285
Physics
Optics
Scientific paper
In planetary radio occultation, atmospheric refractivity profiles are typically constructed by applying Abel inversion upon observed amplitude and phase data. But the Abel inversion has limitations. Being derived from ray theory assumptions, Abel inversion produces diffraction-limited profiles having vertical resolutions no better than the diameter of the first Fresnel zone, ˜2sqrt{λ D}, where D is the distance between the spacecraft and the observed ray periapse. Thus, Abel inversion alone cannot resolve sub-Fresnel-scale atmospheric features such as sharp temperature inversions, waves, etc. Also, the planetary limb can diffract (as commonly observed in occultation data from Mars Global Surveyor) and hinder profile recovery by masking near-surface atmospheric structures. Therefore, by itself, the Abel inversion - a geometrical optics method - cannot uncover diffracting features since diffraction is a wave optics phenomenon. Further, for complete profile recovery, all rays incident upon the atmosphere should be observed. Unfortunately, guiding structures such as ducts can trap rays and complicate, if not preclude, full reconstruction. This research addresses these issues in Abel inversion and profile reconstruction by applications of back propagation. Back propagation has already been shown to effectively reduce the size of the first Fresnel zone for occultation of thin atmospheres and allows the Abel inversion to resolve diffracting structures to vertical resolutions an order of magnitude better than the Fresnel scale. This work further investigates the potential of back propagation in resolving both diffractive and guiding structures in not only thin but also thick atmospheres where bending angles are much larger than for the thin atmosphere case.
Han Chuan-Shou
Tyler Leonard G.
No associations
LandOfFree
Resolving diffractive and guiding structures in thick atmospheres does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Resolving diffractive and guiding structures in thick atmospheres, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Resolving diffractive and guiding structures in thick atmospheres will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-846128