Superconducting integrated receiver development for TELIS

Abstract

TELIS (TErahertz and submm LImb Sounder) is a cooperation between European institutes, DLR, RAL, and SRON, to build a three-channel balloon-borne heterodyne spectrometer for atmospheric research. Many atmospheric trace gases have their rotational transitions in the sub millimeter and THz range, yielding a very rich spectrum. Limb sounding results in very accurate vertical profiles.All three TELIS receivers will operate simultaneously. 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 , O 3 , H 2 O, O 2 , and HOCl. Finally the 550 -650 GHz channel is developed by SRON and IREE and will measure profiles of ClO, BrO, O 3 and its isotopologues, HCl, HOCl, H 2 O and its isotopologues, HO 2 , CO, NO, N 2 O, HNO 3 , CH 3 Cl, and HCN.TELIS will fly on the MIPAS-B2 gondola. The two instruments together will yield the most complete set of stratospheric constituents. The qualification flight is foreseen in the winter of 2006/2007. The TELIS instrument serves as a test bed for many novel cryogenic heterodyne technology: novel low-noise cryogenic heterodyne mixer detectors, novel low-noise cryogenic intermediate-frequency amplifiers, novel back-end spectrometer. In the presentation these technologies will be discussed and compared with 'conventional' technology as applied in the Microwave Limb Sounder (MLS) on EOS-Aura, launched in 2004. Emphasis will be on the science and technology of the channel developed by SRON. It contains a Superconducting Integrated Receiver (SIR), which combines on a 4x4 mm 2 chip the low-noise Superconductor-isolator-Superconductor (SIS) mixer and its quasi-optical antenna, a superconducting phase-locked Flux Flow Oscillator (FFO) acting as Local Oscillator (LO) and SIS Harmonic Mixer (HM) for FFO phase locking. Latest test results and retrieval simulations will be presented.

Superconducting Integrated Submillimeter Receiver for TELIS

“…The optical front-end of TELIS [2], [3], [4] consists of a pointing telescope, calibration blackbody and relay optics, common for the three channels: 500 GHz, 550-650 GHz and 1.8 THz. Frequency separation between the channels is performed quasioptically, allowing simultaneous observations by all receivers.…”

Balloon-borne heterodyne stratospheric limb sounder TELIS ready for flight

“…The result of the PLL on the FFO spectrum measured at one of the flight frequencies selected for TELIS is shown in Figure 5. The impact of the non-perfect FFO spectrum on the retrieval accuracy is discussed in [21].…”

“…From the spectra vertical profiles of trace gases will be determined in an off-line retrieval process. The retrieval is based on the comparison between a calculated spectrum and the measured spectrum [21]. The emission spectrum is calculated in a so-called forward model by integrating the radiative transfer equation along the line of sight (LoS), for a given temperature and pressure profile, for assumed molecular density height profiles, and for the observation geometry.…”

Stratospheric isotopic water profiles from a single submillimeter limb scan by TELIS

“…This chip is developed in collaboration with Institute of Radio Engineering and Electronics (IREE), Moscow, and is a major step in the miniaturisation of submillimeter receiver systems. For details we refer to Hoogeveen et al (2005); Koshelets et al (2007).…”

“…In this paper the possibilities of isotopic water retrieval from the 480-650 GHz channel of the balloon borne instrument TELIS (TErahertz and submillimeter LImb Sounder) (Hoogeveen et al, 2005;Yagoubov et al, 2008) are investigated by retrieval simulations. The outline of this paper is as follows.…”