24.11.2015
In May 2015 the Joint Research Project “Microwave and terahertz metrology for homeland security (THz Security)“ was completed successfully. In the project PTB cooperated with five other metrology institutes and partners from industry and universities on the traceability of measurands in the THz frequency region.
The Joint Research Project “Microwave and terahertz metrology for homeland security (THz Security)“ aimed at improving the capabilities for traceability of measurement quantities in novel THz systems. THz spectrometers and security scanners based on microwave and THz radiation are more and more used for security applications. The traceability of radiated signals and the evaluation of heat transfer into the skin of persons exposed to the field remained mostly unresolved problems. Material parameter measurements in different kinds of THz spectrometers showed only limited comparability.
Besides coordination of the project, different aspects of the above mentioned challenges have been addressed in the working group Electromagnetic Fields and Antenna Measuring Techniques. A free space spectrometer based on vector network analysis was established and a new, easy to use procedure for extracting material parameters was developed. Using the spectrometer, extensive investigations on the measurement uncertainty were carried out. In different measurement campaigns, the emission from different security scanners was measured and evaluated. The heat transfer into the skin of persons exposed to the field was examined based on a comparison of calculations and thermographic measurements on a skin phantom.
The results obtainedby the research project were presented in a workshop with participants from project partners and stakeholders from industry, universities, research organizations and regulatory authorities. On May 29, 2015, about 30 persons from this group met at the Physikalisch-Meteorologisches Observatorium Davos (PMOD) to discuss results and further research (Figure 1).
Fig. 1: Participants of the workshops “THz Security – Microwave and terahertz metrology for homeland security” in front of the PMOD building in Davos.