Performance Characterization of the Atmospheric Velocity Imaging Detector (AVID)

Abstract:

Central to the improvement of upper atmospheric models is a dramatic expansion in current understanding of the coupling and dynamics within the Ionosphere / Thermosphere (IT) system. Conventional in situ measurement techniques using energy scanning and analog current detection are limited by poor sensitivity and have produced incomplete datasets. The Atmospheric Velocity Imaging Detector (AVID) overcomes the limitations of current instruments through the use of two orthogonally mounted Imaging Dispersive Energy Analyzers (IDEAs) which share a single pulse-counting ion detector. The second-generation IDEA design uses inexpensive and lightweight printed circuit boards, with parallel exposed copper traces connected via resistors to generate a highly uniform deflection field. This arrangement allows AVID to make accurate and sensitive in situ measurements of neutral wind / ion drift velocities, temperature, density, and composition, with no voltage scanning required. We present results from the development progress of AVID, through laboratory testing and characterization of an individual IDEA unit when exposed to angle-resolved hypervelocity ion beams emulating 4.7 eV O and 8.2 eV N₂. Through these measurements, the projected performance of the AVID system and recently developed image processing algorithms are compared against SIMION ion trajectory calculations and Monte Carlo simulations.