A novel but technologically demonstrated Fabry-Perot interferometer (FPI) is applied to 630 nm observations. These observations bring the order-of-magnitude sensitivity required to untangle the long-standing mystery of the thermospheric dynamics producing the midnight temperature maximum (MTM). The Fabry-Perot is first fielded at the Arecibo Observatory to simultaneously apply the nested diagnostics of the incoherent scatter radar and all-sky imaging to resolution of the MTM dynamical source. Subsequently, the instrument is moved to Argentina to fill a gap in the growing chain of optical instruments for aeronomy research in South America.
