A device and method for dynamically adapting spatial resolution for imager Fourier transform spectrometers makes it possible to acquire data in interferogram mode and image mode on survey points for an observed scene, each survey point being associated a matrix of macro-pixels and defined by a plurality of zones. For each survey point, analysis of the content of each zone is carried out on the basis of data of the image mode. Classification into clear zone or non-clear zone is carried out as a function of proportion of cloud, and clear-pixel data are generated on the basis of the sum of the data of the macro-pixels of the clear zone class. Survey point data are generated on the basis of the sum of the data of all the macro-pixels of the matrix associated with the survey point. The survey point and clear pixel data streams are transmitted to the ground.