Gravity waves (GWs) are generated in a fluid medium such as atmosphere or ocean when it is perturbed and the gravity/buoyancy acts as restoring force. Gravity waves are ubiquitous in the atmosphere and occur in a variety of spatial and temporal scales. They play an important role in the atmosphere thermal equilibrium and global circulation. This talk will focus on observational studies of gravity waves propagating in mesosphere and lower thermosphere (80-110 km). In this region, active and passive optics methods are used to observe atmospheric properties. Data acquired from a narrow-band sodium lidar, airglow imager and meteor radar are used to analyze the gravity waves characteristics. This talk will also give an overview of the plans for the upcoming superpressure balloon Strateole-2 campaign, and a description of the ROC2 instrumentation that will be deployed in the 2018 technology validation campaign.