:TELIS meeting N.Suttiwong Status of 1.8 THz Channel TELIS (TErahertz and submm LImb Sounder) by Nopporn Suttiwong, Remote Sensing Technology Institute, DLR Oberpfaffenhofen

4/12/2007, Slide 2 N.Suttiwong 1.8 THz Channel (DLR) Mixer: Hot Electron Bolometer (HEB) Diplexer for coupling in LO DSB mode LO: solid state LO technology Digital autocorrelator spectrometer Preliminary design of the 1.8 THz Channel

4/12/2007, Slide 3 N.Suttiwong 1.8 THz Receiver : Diplexer Characterization at 4 K Diplexer Overview 1.8 THz channel in the filght module cryostat  Diplexer was characterized at 4K in the flight module cryostat.  LO Frequency : THz  The figure shows the comparison of the expected diplexer position and the real measurement. Maximum output power  MPI based Diplexer  Leakage is about 0.7%  Optimizing Adjustment on absolute power

4/12/2007, Slide 4 N.Suttiwong  Diplexer was characterized at 4K in the flight module cryostat.  LO Frequency : THz  The figure shows the comparison of the expected diplexer position and the real measurement. Maximum output power 1.8 THz Receiver : Diplexer Characterization at 4 K Comparison of NT spectrum and the calibrated spectrum measured from optimizing with HEB‘s current and the one optimized with absolute power

4/12/2007, Slide 5 N.Suttiwong 1.8 THz Receiver : Measurement Setup Methanol Gascell

4/12/2007, Slide 6 N.Suttiwong 1.8 THz Receiver : Stability of receiver Integration time = 2 sec ~25 minutes measurement Cooler at 10 K LO: GHz Absolute power from ACS (926 channels) Standard deviation ~ +/- 0.4%

4/12/2007, Slide 7 N.Suttiwong Noise temperature spectrum(across 2 GHz bandwidth)  measured in DSBmode  LO was tuned at GHz  Absolute NT ~2100 K 1.8 THz Receiver : System Noise Temperature Spectrum From measurement on D:\TELIS\Measurement_results\2007\2730_11_2007_MicrowindowTHzCH\29_11_2007\ck_uWindows_reproducibility\2_c\ACS\mea2

4/12/2007, Slide 8 N.Suttiwong The methanol spectrum measured in DSB mode  Measure Sequence : H-G-C-A- …  LO was tuned to THz  Sample gas : methanol Cell length : 50 cm. Window material : PE 1.8 THz Receiver : Methanol Spectrum

4/12/2007, Slide 9 N.Suttiwong Microwindow Selection for THz channel * IF = 5 GHz SpeciesLine center/GHzLO range/GHzSideband OH USB OH LSB H2O USB H2O LSB H2O USB H2O LSB O USB HO USB CO USB HCl USB

4/12/2007, Slide 10 N.Suttiwong

4/12/2007, Slide 11 N.Suttiwong Atmosphere Remote Sensing Measurement TELIS instrument Recently Test Ph.D Work packages  Why DSB mode on the first flight ?  SSB filter causes the extra standing wave in the system  SSB filter generates the audio-frequency at 4K

4/12/2007, Slide 12 N.Suttiwong Microwindow Selection for THz channel SPECIESPRIORITYLine center [GHz] Line center [cm-1] LO [GHz]Side Band OHhighest1837,7861,301832,78USB HO 2 prefer.highest1781,8659,441786,81LSB HO 2 highest1821,8360,771816,83USB O2O2 highest1870,0562,381875,05LSB NOmiddle1853,5961,831858,59LSB NO 2 middle1854,5861,861859,58LSB HClmiddle1873,462,491868,4LSB H2OH2Omiddle1853,8961,841858,69LSB O3O3 middle1835,8461,241830,84USB COlow1841,3661,421836,36USB HOCllow1782,6959,461777,82USB HOCl prefer.low1772,8259,141777,82LSB H2O2H2O2 low1849,0061,681844,00USB * IF = 5 GHz

4/12/2007, Slide 13 N.Suttiwong 1.8 THz receiver : NT Measurement TELIS instrument Ph.D‘s Goal Overview Cryogenic 1.8 THz Channel Ph.D Work packages

4/12/2007, Slide 14 N.Suttiwong The NT measurement (solid state LO) The NT measurement (FIR laser) TELIS instrument Ph.D‘s Goal Overview Cryogenic 1.8 THz Channel Ph.D Work packages 1.8 THz Receiver : System Noise Temperature

4/12/2007, Slide 15 N.Suttiwong 1.8 THz channel Prerequirement Radiometric T sys : <600 K (RAL) <400 K (SRON) <6000 K (DLR) Gain error:<1% Offset error: <1 K Baseline ripple: <0.1 K Spectral Resolution: <4 MHz Range: 2 GHz (SRON, DLR) 4 GHz (RAL) Accuracy : <2 MHz Atmosphere Atmosphere Remote Sensing Measurement TELIS instrument Recently Test Ph.D Work packages

4/12/2007, Slide 16 N.Suttiwong Development of 1.8 THz Channel in Testing Cryostat Transfer 1.8 THz channel to the TELIS’s flight module cryostat Software development for laboratory test Software development (ground) for the post processing which will be used in campaign Hardware : Software : Scientific work: Characterization of 1.8 THz Channel in Testing/Flight Module Cryostat Characterization of the TELIS’s IF backend IF chain Digital autocorrelator spectrometer Analysis the measurement data from the first campaign (Teresina, Brasil : Nov 2007) Focus-> OH ; Satellite validation of MLS/Aura What to be achieved? TELIS instrument Ph.D‘s Goal Overview Cryogenic 1.8 THz Channel Ph.D Work packages

4/12/2007, Slide 17 N.Suttiwong Optical bench Window Cryogenic THz channel Signal TELIS instrument Ph.D‘s Goal Overview Cryogenic 1.8 THz Channel Ph.D Work packages

4/12/2007, Slide 18 N.Suttiwong Cryogenic THz channel Polarizer SSB filter TELIS instrument Ph.D‘s Goal Overview Cryogenic 1.8 THz Channel Ph.D Work packages

4/12/2007, Slide 19 N.Suttiwong Cryogenic THz channel Imaging Mirror LO SSB filter TELIS instrument Ph.D‘s Goal Overview Cryogenic 1.8 THz Channel Ph.D Work packages

4/12/2007, Slide 20 N.Suttiwong Cryogenic THz channel LO HEB Diplexer Imaging Mirror f IF(USB) = f S -f LO or f IF(LSB) = f LO -f S SSB filter TELIS instrument Ph.D‘s Goal Overview Cryogenic 1.8 THz Channel Ph.D Work packages

4/12/2007, Slide 21 N.Suttiwong What has been done? / What to do more? TELIS instrument Ph.D‘s Goal Overview Cryogenic 1.8 THz Channel Ph.D Work packages

4/12/2007, Slide 22 N.Suttiwong First Integration of TELIS with MIPAS ( ): “TELIS side view” TELISMIPAS-B Flight module cryostat Telescope, Optical Module Autocorrelator plate “TELIS with MIPAS”

4/12/2007, Slide 23 N.Suttiwong TV Test in Karlsruhe ( ): “TELIS in Vacuum Chamber” Heat pipe and Black body Analog/Digital Racks Autocorrelator Plate

4/12/2007, Slide 24 N.Suttiwong Limb Sounding Measurement from balloon platform  Atmospheric profiles of molecular abundances, temperature, and pressure can be determined from the measured emission spectra. Atmosphere Remote Sensing Measurement TELIS instrument Recently Test Ph.D Work packages

4/12/2007, Slide 25 N.Suttiwong Software Development: PC104 HEB,LO,Dip,SSB, Telescope, etc. ACS DB Server Spectrum Post- Processing Raw Data Calibrated Spectra TCP/IP Balloon Ground Autocorrelator calibration Spectral post-processing Quantization correction Calibrating the raw spectra

4/12/2007, Slide 26 N.Suttiwong TELIS instrument’s specification Radiometric T sys : <600 K (RAL) <400 K (SRON) <6000 K (DLR) Gain error:<1% Offset error: <1 K Baseline ripple: <0.1 K Spectral Resolution: <4 MHz Range: 2 GHz (SRON, DLR) 4 GHz (RAL) Accuracy : <2 MHz Atmosphere Atmosphere Remote Sensing Measurement TELIS instrument Recently Test Ph.D Work packages

4/12/2007, Slide 27 N.Suttiwong Atmosphere Remote Sensing Measurement TELIS instrument Recently Test Stability of THz channel system Ph.D Work packages Bolometer Testing cryostat A strong influence on the receiver stability comes from the LO source. The utilization of a solid state LO provides the better system stability of the THz channel. The coupling optics was carefully designed in order to provide sufficient LO power to drive the HEB mixer. The output power of LO (measured by Bolometer)

4/12/2007, Slide 28 N.Suttiwong Atmosphere Remote Sensing Measurement TELIS instrument Recently Test Ph.D Work packages What has been done? / What to do more?

4/12/2007, Slide 29 N.Suttiwong TELIS Team DLR Institut für Planetenforschung HEB mixer for 1.8 THz channel RAL Rutherford Appleton Laboratories, U.K. 500 GHz channel, level 2 processing, cryostat design and fabrication SRON Space Research Organisation of the Netherlands 600 GHz channel, level 2 processing, optical design, HIFI technology Chalmers University of Technology, Sweden HEB mixer for 1.8 THz channel, level 2 processing Institut für Meteorologie und Klimaforschung Forschungszentrum Karlsruhe Gondola, consultancy Institut für Umweltphysik, Uni Bremen Consultancy DLR Abteilung MORABA Microcontroller, consultancy Institut für Mikrowellentechnik Universität Bern, Switzerland Consultancy optical design, heterodyne receiver, antenna profiles, spectrometer DLR Institut für Methodik der Fernerkundung PI, total system, 1.8 THz channel

4/12/2007, Slide 30 N.Suttiwong TELIS instrument overview Limb sounding technique Balloon platform: height range km, altitude resolution 2 km TELIS consists of three channels: DLR : 1830  40 GHz SRON : 600 – 660 GHz RAL: 499 – 503 GHz MIPAS &TELIS on the same platform Species measured by TELIS DLR : OH, HO 2, HCl, NO, NO 2, O 3, H 2 O, O 2, HOCl RAL : BrO, ClO, O 3, N 2 O SRON : ClO, BrO, O 3, HCl, HOCl, H 2 O, HO 2, NO, N 2 O, HNO 3, CH 3 Cl, HCN, H 2 18 O, H 2 17 O, HDO TELIS instrument TELIS highlights MIPAS gondola „with TELIS“ Sensitivity improved vs. MIPAS-B Ph.D‘s Goal Overview Cryogenic 1.8 THz Channel Ph.D Work packages

4/12/2007, Slide 31 N.Suttiwong TELIS instrument’s schematic diagram Telescope Pointing Controller Thermal Radiation Source Autocorrelator Spectrometer (4ch x 2GHz) IF chain (4- 6GHz) IF chain (5-7 GHz) IF chain 2 x 2-4 GHz PC104 MIPAS Altitude and heading reference system House Keeping Unit (Temperature, Voltage) Server ComputerClient Computer Balloon Ground Atmosphere DLR HEB mixer SRON Integrated Receiver RAL SIS mixer LO generation SSB filter Diplexer SSB filter Cryostat Pointing motor /encoder Transferoptic Rate Gyroscope TELIS instrument Ph.D‘s Goal Overview Cryogenic 1.8 THz Channel Ph.D Work packages

4/12/2007, Slide 32 N.Suttiwong Cryogenic THz channel Cryostat Window Optical bench SSB filter (MPI) Diplexer (MPI) Mixer (HEB) LO TELIS instrument Ph.D‘s Goal Overview Cryogenic 1.8 THz Channel Ph.D Work packages