Disclosed herein is an active seeker system for detection and/or tracking of moving targets. The system includes: an illumination module generating an illumination beam to be output from the system; an optical assembly for shaping the solid angle of the field of view (FOV) of the output beam; an optical path scanning module adapted for angularly deflecting the output optical path of the output beam about a scan axis to perform one or more scanning cycles; and an imaging module adapted to image light in the spectral regime of the beam, arriving from a certain field of view about the output optical path of the beam. In some cases, the solid angle of the output light beam is shaped such that it has an elongated FOV cross-section extending along a certain lateral of the beam; and the output optical path is angularly deflected in a direction travers to the longer axis of the elongated FOV of beam so as to swipe the elongated FOV of the beam to cover a desired field of regard (FOR) with one dimensional scanning. In some implementations, the system is adapted for monitoring the FOR for detecting and tracking the target. The monitoring may include a target detection stage during which the FOV of the light beam is set to an extent smaller than the FOR and the FOR is imaged in a scanning imaging mode. The monitoring may include a target tracking stage during which one or more imaging parameters are adjusted according to certain estimated properties associated with the target being tracked.