Longwave Infrared Hyperspectral Imaging: Principles, Progress, and Challenges

Longwave infrared (LWIR) hyperspectral imaging (HSI) sensors provide valuable information for numerous military, scientific, and commercial applications. The hyperspectral signal exploitation principles are the same in the reflective and emissive regions of the spectrum. However, the underlying phenomenology and interaction with the environment are different in the two regimes of the spectrum. These differences affect all aspects of thermal IR HSI, from sensor design to data exploitation. The main objective of this article is to explain the unique aspects of thermal IR HSI, review the progress that has been made, and highlight existing challenges and areas for future research.