This paper describes the operating principles behind AOTFs, which are solid state devices that act as narrow optical filters when a traveling acoustic wave interacts with incident radiation in the crystal. Tunable cameras utilizing AOTFs provide great flexibility, since they are very compact, electronically programmable, and have low power requirements. They have extensive heritage in ground-based instruments with planetary science applications and they are radiation tolerant, hence they are well-suited to balloon-borne platforms.

While there is a myriad of potential applications of hyperspectral imaging to solar system targets, this paper discusses several example use cases for a balloon-borne AOTF imaging system: synoptic studies of clouds on the giant planets and Venus, the mapping of hydrocarbon ices on the surfaces of icy bodies, studies of cometary comae, and polarimetry. The paper describes a notional AOTF imager design that includes both visible and near-infrared channels, in order to take full advantage of the spectral coverage of an AOTF.

The AOTF technology would greatly benefit from flight demonstration on a high-altitude balloon. Balloons have long served as a proving ground for testing instrument prototypes for high-energy and particle astrophysics, solar physics, and Earth science, some of which eventually flew on satellites. AOTF technology would benefit similarly, with the ultimate goal of developing an AOTF-based instrument for planetary flight projects.