A Method to Calculate the Ionospheric LBH Dayglow Emissions for Large Field of View
LBH dayglow emissions in the ionosphere, produced by the photoelectrons impact on the nitrogen molecules, are the most prominent molecular signals in the far ultraviolet range. Imaging the LBH dayglow emissions from the space can be a powerful method to monitor the state of the upper atmosphere. According to direct excitation theory and spherical geometry, the spectral characteristics of the LBH emission are analyzed and a revised method (RAURIC) to calculate the column emission rate of the LBH dayglow emissions for large field of view is given. Two main limitations of AURIC, that are the definition of the observation azimuth angle and the treating of the solar zenith angle as a constant along a line of sight, are improved in RAURIC. The column emission rates of the LBH bands in the range of 140∼180 nm are calculated with the method. Comparisons with results from AURIC show great agreement in nadir, while RAURIC should be used in other lines of light, especially for large field of view. This work provides a solid basis for simulating the image of ionospheric LBH dayglow emissions and the data inversion technique.