Gravity waves are an important coupling mechansim between the different compartents of the atmosphere: chiefly generated in the troposphere, they propagate upward and deposit momentum and energy in the stratosphere and mesosphere. Infrared limb sounder measure GWs by means of their temperature structures. GLORIA offers the opportunity to deduce the 3D temperature field inside closed flight patterns. Determining the horizontal and vertical wavelength, the momentum flux carried by a wave can be calculated. In addition, the wave can be backtraced to its source region. This is illustrated in the Figure of GWs generated by flow over the topography of Greenland taken from a study for a limb imager in space. GLORIA was therefore an essential part of the instrumentation for the HALO mission GW-LCYCLE (led by DLR). The campaign studied the generation, propagation and dissipation of GWs by combining different air-borne and ground-based measurements complemented by modeling efforts.