POSSIBILITIES FOR THE STUDY OF THE NLTE EFFECT ON ATMOSPHERIC CO_2 SPECTRAL SIGNATURES INDUCED BY A BLUE JET USING AN INFRARED SPECTROIMAGER EMBEDDED IN A STRATOSPHERIC BALLOON.

摘要

HALESIS (High Altitude Luminous Events Studied by Infrared Spectro-imagery) is an innovative project based on hyperspectral imagery. The purpose of this experience is to measure the atmospheric perturbation in the minutes following the occurrence of Transient Luminous Events (TLEs) from a stratospheric balloon in the altitude range of 20 to 40 km. The first part of the study has been dedicated to establish the project feasibility. To do that, we have simulated spectral perturbations induced by an isolated blue jet. Simulations have been performed using the line by line radiative transfer model LBLRM taking into account the Non Local Thermodynamic Equilibrium. The case of the estimation of the CO_2 infrared signature that could be the result of a single blue jet occurrence is presented. Then, the estimated spectral signatures have been confronted with the technical capabilities of different kinds of hyperspectral imagers. The study has demonstrated the feasibility of the project, but it has also pointed to the challenges to build perfectly adapted instrument.