Balloon-borne heterodyne stratospheric limb sounder TELIS ready for flight

Abstract

TELIS (TErahertz and submm LImb Sounder) is a three-channel balloon-borne heterodyne spectrometer for atmospheric research. The observational techniques of TELIS can be compared to the presently flying MLS instrument on board NASA's EOS-Aura satellite, but TELIS is built with a new generation of cryogenic heterodyne detectors and novel compact systems suitable for integration into the confined space of a balloon borne cryostat. TELIS will fly on the MIPAS-B2 gondola. The two instruments together will yield the most complete set of stratospheric constituents, measured so far. TELIS is a cooperation between the European institutes DLR (PI-institute), RAL and SRON. First flight foreseen in the spring of 2008 from Teresina, Brasil.The three TELIS receivers provide simultaneous vertical profile measurement of a range of molecules. The 500 GHz channel is developed by RAL and will produce vertical profiles of BrO, ClO, O 3 and N 2 O. The 1.8 THz channel is developed by DLR and will mainly target the OH radical, and will also measure HO 2 , HCl, NO, NO 2 , O3, H 2 O, O 2 and HOCl. Finally the 480 -650 GHz channel is developed by SRON and IREE and will measure profiles of ClO, BrO, O 3 , HCl, HOCl, H 2 O and its 3 isotopomers, H 2 O 2 , NO, N 2 O, HNO 3 , CH 3 Cl and HCN.In this paper, the science and technology of TELIS will be discussed with emphasis on the channel developed by SRON. It contains a Superconducting Integrated Receiver (SIR), which combines on a 4x4 mm 2 chip the low-noise SIS mixer and its quasioptical antenna, a superconducting phase-locked Flux Flow Oscillator (FFO) acting as Local Oscillator (LO) and a SIS harmonic mixer (HM) for FFO phase locking. The latest results from the pre-flight test and integration campaigns will be presented.

Development and characterization of the superconducting integrated receiver channel of the TELIS atmospheric sounder

“…The stability determines the optimum achievable measurement time for a single integration, and thus the required frequency of the calibration cycle. The stability of the complete TELIS-SIR system has been determined with a noise-fluctuation bandwidth of 17 MHz and the results [3] are presented in figure 8. For the two IF channels that are used to determine the Allan variance it is found that the Allan stability time is about 13.5 s. When the difference of the two channels is taken to determine the Allan variance (this is the so-called spectroscopic, or differential, mode), an Allan stability time of 20 s is found.…”

“…TELIS (TErahertz and submillimetre LImb sounder) [1][2][3] is a three-channel balloon-borne heterodyne spectrometer for atmospheric research developed in a collaboration of three institutes: Deutsches Zentrum für Luft-und Raumfahrt (DLR), Germany, Rutherford Appleton Laboratories (RAL), United Kingdom, and SRON-Netherlands Institute for Space Research, the Netherlands. The three receivers utilize stateof-the-art superconducting heterodyne technology and operate at 500 GHz (by RAL), at 480-650 GHz (by SRON in tight collaboration with Kotel'nikov Institute of Radio Engineering and Electronics, IREE, Moscow), and at 1.8 THz (by DLR).…”

“…Both instruments observe simultaneously the same air mass, and together they yield an extensive set of stratospheric constituents that can be used for detailed analysis of atmospheric chemical models, such as ozone destruction cycles. In particular, the 480-650 GHz TELIS channel is able to measure vertical profiles of ClO, BrO, O 3 and its rare isotopologues, O 2 , HCl, HOCl, H 2 O and three rare isotopologues, HO 2 , NO, N 2 O, NO 2 , HNO 3 , CH 3 Cl, and HCN. In this paper the design and technology for the 480-650 GHz channel as used in the flight configuration are presented in conjunction with test results and the first preliminary scientific results.…”