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We present a method for estimating incident photoelectrons’ energy spectra as a function of altitude by combining global scale far-ultraviolet (FUV) and radio-occultation (RO) measurements. This characterization provides timely insights important for accurate interpretation of ionospheric parameters inferred from the recently launched Ionospheric Connection Explorer (ICON) observations. Quantification of photoelectron impact is enabled by the fact that conjugate photoelectrons (CPEs) directly affect FUV airglow emissions but not RO measurements. We demonstrate the technique for the estimation of photoelectron fluxes and their spectra by combining coincident ICON-FUV and COSMIC2 measurements and show that a significant fraction of ICON-FUV measurements are affected by CPEs during the winter solstice. A comparison of estimated photoelectron fluxes with the SAMI2-PE model is used to gain further insights into the estimation method and reveals consistent values at low latitudes, while the results suggest that the model might be overestimating photoelectron fluxes by 10\% at mid latitudes.