“…Slitless spectroscopy is a well known technique to analyze the absortion and emission of light coming from a narrow source, that consists of an optical system including a diffraction element and a sensor. It is a very useful tool to analyze the spectrum of natural (Boggs et al., 2021; Orville, 1968; Prueitt, 1963; Uman, 1963) and triggered lightning (Walker & Christian, 2019; Weidman et al., 1989) since it provides a wide field of view which usually allows to capture the whole lightning stroke in the camera sensor, which not only permits to measure the electron density and temperature in the lightning core (Prueitt, 1963; Uman, 1963; Walker & Christian, 2017, 2019), but also vertical temperature profiles in natural lightning return strokes (Boggs et al., 2021). Unfortunately, slitless spectroscopy makes difficult to discern wavelengths among nearly coincident lightning flashes, besides the serious limitations it presents for wavelength and, especially, for flux calibrations that could negatively affect spectral data reduction.…”