A hyperspectral camera was used to measure the emission spectrum of a V-shaped hydrogen flame. Medium resolution (0.25 cm−1) spectra were obtained. The inversion of experimental spectra was performed using an SPSO algorithm combined with a ℓ-distribution method as forward model. The ℓ-distribution approach was chosen to model the experimental data instead of an LBL method in order to reduce the CPU cost of the inversion process. The maximum errors obtained on preliminary test cases (analysis of high resolution synthetic spectra convolved by a Gaussian instrument function) are less than 1.0 K for temperatures and 3×10−3 for species concentrations. Finally, the method was applied to an experimental spectrum. A 1275 K flame temperature and 0.113 H2O molar fraction were obtained. These values are close to those expected for the configuration studied.