HR: 1340h
AN: SA53A-1164    [Abstracts]
TI: In-Situ Measurements of Atomic Oxygen in the MALT Region: The ATOX Resonance Fluorescence/Absorption sensor
AU: * Patterson, P
EM: patp@sdl.usu.edu
AF: Space Dynamics Laboratory, 1695 North Research Parkway, North Logan, UT 84342 United States
AU: Swenson, C M
EM: charles.swenson@engineering.usu.edu
AF: Utah State University, 4120 Old Main Hill, Logan, UT 84322 United States
AB: The Utah State University Atomic Oxygen (ATOX) sensor was launched aboard the Coupling of Dynamics and Aurora (CODA) payloads on January 22, 1999 from Poker Flat, Alaska and again on February 21, 2001, both into diffuse auroras. Atomic oxygen profiles were measured in-situ by a combination of resonance and florescence techniques. While the resonant fluorescence technique appears well suited for the measurement of O in the MALT, the dynamics of the sounding rockets which carry the sensor system create challenges that the system and data analysts must overcome. Primary challenges include density flow field disturbances, Doppler shift of the source lamp emission, and contamination. It has been well documented that these challenges, especially the flow field disturbances, make it difficult to accurately measure O concentration profiles. Our research has quantified the effect of the three major disturbances, seen as errors, and attempts to correct for each. Computations show that the largest errors are introduced by flow field disturbances. With a strong dependence upon measurement attitude and mission geometry, errors in the ram direction are often in excess of 300%. Errors as large as 100% are introduced by Doppler shift of the lamp output, and errors upwards of 40% are introduced into the absorption measurements due to contamination. An approach will be discussed that can potentially reduce errors in both the fluorescence and absorption measurements to within 15 - 20% of undisturbed values. Furthermore, since the corrections are applied across the entire measurement region, direct comparison of upleg and downleg measurements is now possible.
DE: 0322 Constituent sources and sinks
DE: 0355 Thermosphere: composition and chemistry
DE: 0394 Instruments and techniques
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005