  Waves can be used to probe and image an unknown medium. Passive imaging uses
ambient noise sources to illuminate the medium. This paper considers passive
imaging with moving sensors. The motivation is to generate large synthetic
apertures, which should result in enhanced resolution. However Doppler effects
and lack of reciprocity significantly affect the imaging process. This paper
discusses the consequences in terms of resolution and it shows how to design
appropriate imaging functions depending on the sensor trajectory and velocity.
