Apparatus and methods are disclosed utilizing selected infrared waveband observations to determine selected profiles of interest. A correlative system is constructed and installed at a processor. Thermal and refractivity profiles and structure in a waveband of interest are extracted from observed infrared spectrum single waveband observations received for processing at the processor by the correlative system. The output provides the selected profiles of interest in the waveband of interest. The apparatus includes an infrared receiver and means for measuring angular displacement of received emissions relative to a horizon. The processor converts received emission into equivalent Planck blackbody temperatures across the observations and correlates structure and vertical distribution of the temperatures to provide thermodynamic and refractivity profiles of interest.