A system for determining a region of interest for an imaging device based on instrument landing system (ILS) is provided herein. The system may include an imaging device attached to an aircraft; an ILS detector; a computer processor configured in to calculate in a line of sight between said aircraft and a planned touch down point, based on the received ILS signals; a touchdown positioning module executed by the computer processor and configured to calculate a position in a field of view (FOV) of said imaging device which represents the planned touchdown point, based on said line of sight; and a region of interest (ROI) module executed by the computer processor and configured to define a region of interest (ROI) of the imaging device based on said position in said FOV, wherein said computer processor is further configured to apply an image processing operation only to data within said ROI.