MULTIFREQUENCY IMAGING METHOD AND APPARATUS

摘要

Terahertz imaging apparatus uses multiple frequencies simultaneously to obtain images of a field of view. In this at least one terahertz receiver 300-320 detects the incoming radiation 340 from a field of view to form an image. The image data is then transferred to a preprocessor 325 before being sent to an image signal generator 330, which combines the frequencies into a colour coded composite image in which differences in properties of materials at the different frequencies give rise to colour differentiation in the composite image. The image processor can provide gray scale image data at each of the different respective frequencies and the composite image generator is provided with a colour map having constituent colours with the generator being adapted to apply a respective constituent colour to the gray scale image data at the respective frequencies. The apparatus can be used for security purposes such as the detection of concealed objects.