The air pollution is a hot scientific and political issue. Its importance was confirmed once again by the Nobel Prize for Peace 2007. However, the long term forecast of the possible consequences for the Earth and civilization can only be made based on exact atmospheric models. Obviously, all scientific models are based on facts and all models require careful experimental verification. It has been already accepted that the global coverage of the atmosphere monitoring can be achieved from space, i.e. from orbiting the Earth satellites. Such environmental satellites have been already used (e.g. Swedish Odin, or NASA's EOS-MLS), and a number of them are foreseen in the future.
Molecular spectroscopy is probably the most powerful tool to measure which gases and in what concentration exist in different atmospheric layers. It has been proven that terahertz range (100GHz-3THz) contains fingerprints of many important atmospheric pollutants (i.e. CO2). Instruments for terahertz spectroscopy are called radiometers, and some of them have already been used in space and on stratospheric balloons, confirming their importance for global environmental monitoring. As the technology evolves, new horizons open up for instruments developers. E.g. recent progress with terahertz integrated circuit receivers, low noise amplifiers, and advances in Schottky diode technology at Chalmers University of Technology, has created a unique opportunity for terahertz radiometers of a new class: high performance, compact, cost effective. In collaboration with Onmisys Instruments AB, one of the world’s leader in high frequency instrumentation, new radiometer architectures will be explored using the above mentioned techniques. Among the other applications for terahertz radiometers security screening, non-destructive tests, etc., can be named.