Tadar Technology

Mechanically-scanned millimetre-wave imaging systems typically use single, rotating, optical mirrors to focus scene segments onto single or multiple receivers. This approach produces irregular image formats that are very difficult to sharpen in real time. In addition, the optical processing required results in the loss of a major portion of the incident signal radiation and can only be compensated by increasing the number of expensive receivers.

The Tadar camera uses a patented scanning method to produce a linear raster build-up of the scene, which, because of it uniformity, can easily be sharpened by a factor of two, in real time, using standard PC processing power. Tadar’s simple optical reflective surfaces, result in a minimal loss of incoming energy and a minimum number of receivers are needed to image the scene.

The optical system consists of three mirrors that are used to scan the scene and focus the incident radiation onto one or more receivers. The basic configuration is shown in figure 1. The rotation and relative inclination of the plane and concave mirrors combine to focus a spot on the target onto the receiver. This spot on the target travels in a vertical line as the mirrors rotate. The motion of the flapping mirror moves this vertical line scan across the scene to build up a full frame image.