Remote sensing methods (space-borne, air-borne, and ground-based) are presently widely used for obtaining information on atmospheric composition and thermal regime. Modern IR remote sensing methods are based on the validity of local thermodynamic equilibrium (LTE), which is not true in the upper atmosphere (height of breaking of LTE depends on gas, absorption band, and time under consideration). The non-LTE limb radiance has been calculated in 15 μm CO₂ band for tangent heights 50 -110 km. The inverse problem has been formulated including the retrieval of vibrational temperature profiles for the lower vibrational states of CO₂ molecule. The method is based on measurements of high-resolution limb radiance spectra. The retrieval accuracy has been investigated depending on measurement error, spectral resolution, and spectral region used.