TELIS – development of a new balloon borne THz/submmW heterodyne limb sounder

We present a design concept for a new state-of-the-art balloon borne atmospheric monitor that will allow enhanced limb sounding of the Earth's atmosphere within the millimetre and submillimetre wavelength spectral range. The instrument, called TELIS (TErahertz and submm LImb Sounder), is being developed by a consortium of major European institutes that includes the Space Research Organisation of the Netherlands (SRON), the Rutherford Appleton Laboratory (RAL) in the United Kingdom and the Deutschen Zentrum für Luft- und Raumfahrt (DLR) in Germany (lead institute). The TELIS will utilise state-of-the-art superconducting heterodyne technology and is designed to be a compact, lightweight instrument capable of providing broad spectral coverage, high spectral resolution and long flight duration (~24 hours duration during a single flight campaign). The combination of high sensitivity and extensive flight duration will allow evaluation of the diurnal variation of key atmospheric constituents such as OH, ClO, BrO together will longer lived constituents such as O3, HCL and N2O. Furthermore, the TELIS will share a common balloon platform to that of the MIPAS-B Fourier transform spectrometer, developed by the Institute of Meteorology and Climate research of the University of Karlsruhe, Germany. MIPAS-B will provide simultaneous and complementary spectral measurements over an extended spectral range. The combination of the TELIS and MIPAS instruments will provide atmospheric scientists with a very powerful observational tool and, in addition, will act as a prelude to future spaceborne instruments planned by the European Space Agency (ESA).