Terahertz reveals unexplored world

The StarTiger imager operates at two frequencies: 0.25 THz and 0.3 THz. It captures natural submillimetre waves and having responses at two frequencies provides a means for contrasting between materials with different transmission and reflection properties, effectively creating two colours. A hand is here seen captured by the StarTiger imager and the four images illustrated processing steps to extract the information. From left to right:

1. raw data shows pixillation and lines
2. bi-linear resampling reduces line structure
3. information is improved by change of dynamic range
4. using false colours based upon the image taken in two frequencies, brings out more subtle features

By change of image processing focus can be selected according to interest, e.g. the skin, the hand itself or maybe objects behind, i.e. hidden by the hand. It has been verified that objects can be captured through clothes and more solid objects like books.