The platform travels forward in the flight direction (A) with the nadir (B) directly beneath the platform.
The microwave beam is transmitted obliquely at right angles to the direction of flight illuminating a swath (C) which is offset from nadir.
Range (D) refers to the across-track dimension perpendicular to the flight direction, while azimuth (E) refers to the along-track dimension parallel to the flight direction.
This side-looking viewing geometry istypical of imaging radar systems (airborne or spaceborne).