This paper discusses recent activities of the Jet Propulsion Laboratory (JPL) in the development of a new type of remote sensing multispectral imaging instrument using acousto- optic tunable filter (AOTF) as a programmable bandpass filter. This remote sensor filter provides real-time operation; observational flexibility; measurements of spectral, spatial, and polarization information using a single instrument; and compact, solid state structure without moving parts. An AOTF multispectral imaging prototype system for outdoor field experiments was designed and assembled. Some preliminary experimental results are reported. The field system is used to investigate spectral and polarization signatures of natural and man-made objects for evaluation of the technological feasibility for remote sensing applications. In addition, an airborne prototype instrument is currently under development.