Plans for QTT Overall Introduction Wang Na Xinjiang Astronomical - PowerPoint PPT Presentation

Plans for QTT —Overall Introduction Wang Na Xinjiang Astronomical Observatory, CAS May 19-21,2014 Green Bank

Outline • Background • General Plan • QTT Site • Science Goal • Technique Schemes • Progress 2014-5-19 3rd US-China Meeting 2

Background  Almost all of our knowledge about the universe are based on the received electromagnetic radiation by the observer, only a small part are from real material (such as meteor)  The transmission window of the atmosphere for radio frequency: 10MHz ～ 1THz （ 30m ～ 0.3mm ）  Radio wavelength spanning: λmax / λmin ～ 3 × 10 4  Optical: λmax / λmin ～ 2 2014-5-19 3rd US-China Meeting 3

Background Giant single telescopes 美国 305 305 米， 1963 1963 年 中国， FAST 5 500 米，在建 Arrays SKA SKA ，低频阵列，预研 GMRT 低频阵列，印度， 1998 GM 1998 ALMA ， 高频阵列，美国， 2010 2010 年 ALM 2014-5-19 3rd US-China Meeting 4

Background Fully steerable telescopes 德国 100 100 米， 1972 1972 年 英国 76 76 米， 1958 1958 年 美国 100 100× 110 110 米， 2000 2000 年 澳大利亚 64 64 米， 1961 1961 年 2014-5-19 3rd US-China Meeting 5

Background 佘山 25 25 米， 1987 1987 年 南山 25 25 米， 1993 1993 年 昆明 40 40 米， 2006 2006 年 密云 50 50 米， 2005 2005 年 上海 65 65 ， 2012 2012 年 2014-5-19 3rd US-China Meeting 6

General Plan • QiTai radio Telescope (QTT) – Steerable 110m radio telescope 2014-5-19 3rd US-China Meeting 7

General Plan • Features – Prime/Gregorian paraboloid, Az/El – Aperture: 110 m – Fully Steerable – Active Surface – Freq Range 150 MHz – 115 GHz 2014-5-19 3rd US-China Meeting 8

General Plan • Chin China V a VLBI (CV (CVN): astrometry, space exploration CVN+QTT: sensitivity increases 1.8 times CVN+QTT+65m: sensitivity increases 3 times • EV EVN EV EVN SEFD FD ( (Jy Jy) ) SEFD FD ( (Jy Jy) Rat atio Ban and (c (cm) Avai ailab able T Tele le (NS 25 25m) (QT QTT) impro roveme ment 18 10 13 9 30% 13 8 61 17 71% 6 10 14 12 16% 3.6 8 31 21 34% 1.3 6 149 101 33% 2014-5-19 3rd US-China Meeting 9

General Plan • Sur Surfa face Accu Accuracy ( y (rm rms): : – main reflector: ≤0.6mm (no active surface) ≤0.3mm (active surface, long term ≤0.2mm) single panel:≤ 0.07mm – sub-reflector: ≤0.1mm single panel:≤0.05mm 2014-5-19 3rd US-China Meeting 10

General Plan • Pointing Accuracy @ 6m 6mm wa wave length with wind speed≤4m/s, temperature drift≤2 ℃ /h, observation time: 69.5% – blind pointing≤5arcs – repeatability precision≤2.5arcs • QT QTT T Electr tric ic P Perfo forman ance ces Band 100cm 30cm 5cm 1cm 6mm 3mm Efficiency 60% 54% 30% 60% 63% 63% (Optimum El.) ~50% ~30% ~12% System Noise 30 25 20 20 45 100 (K) 2014-5-19 3rd US-China Meeting 11

General Plan Band RF Freq Focus Feed Poln Science Goals Type (cm) (GHz) Pulsar, RRT 100 0.15 – 0.6 Primary Kildal Linear Pulsar, RRT, HI, OH, 30 0.6 – 4 Primary Horn Linear Galaxies Molecular spectrum, 5 2 – 12 Greg. Horn Linear Single Galaxies; VLBI Pixel Pulsar, H2O, NH3, VLBI 1 12 – 36 Greg. Horn Linear Molecular spectrum, 0.6 36 – 50 Greg. Horn Linear High-z CO Molecular spectrum, 0.3 72 – 115 Greg. Horn Linear Galaxies VLBI, space exploration, 2.2 – 2.5 13/3.6 Greg. Horn Circular System measurement Dual- 8 – 9 (3.6cm) Band 8 – 9 VLBI, space exploration 3.6/0.9 Greg. Horn Circular 30 – 34 Pulsar, RRT, HI, OH, 15 1 – 2 Primary PAF Linear Multi- Galaxies Pixel Horn Molecular spectrum, 0.6 36 – 50 Greg. Linear (multi Beam) Galaxies 2014-5-19 3rd US-China Meeting 12

QTT Site Qitai Urumqi Shihezi Village Nanshan Ulastai 2014-5-19 3rd US-China Meeting 13

QTT Site • 1.5 km ×2 km basin • Altitude range from 1730 m to 2250 m • Surrounding ridges form an isolated layer with outside region 2014-5-19 3rd US-China Meeting 14

QTT Site • Elevation of mountain shelter 2014-5-19 3rd US-China Meeting 15

QTT Site • Average annual rainfall of area: – 180 to 200 mm • A verage evaporation capacity of Xinjiang area: – ~2000mm • Atmosp sphe heric ic wate ater vapour ur cont ntent nt: – Summer: ~19 mm – Spring and Autumn: ~9mm – Winter: ~3 mm 2014-5-19 3rd US-China Meeting 16

QTT Site • Temper perature e range: – max +29.3 °, min － 26.6 ° • Temper perature e drifting: Temperature Ratio drifting ≤ 5 ℃ /hr 99.0% ≤ 3 ℃ /hr 92.7% ≤ 2 ℃ /hr 82.7% 2014-5-19 3rd US-China Meeting 17

QTT Site • Freque uency distr y distrib ibution of m f max. ax. win ind sp d speed: Roses diagram Ratio Wind speed Qitai_Day Qitai_Night Qitai_Average GBT ≤ 4m/s (3 beaufort scale) 48.9% 83.0% 65.9% 45.9% ≤ 6m/s (4 beaufort scale) 74.3% 92.9% 83.6% 64.5% ≤ 8m/s (5 beaufort scale) 91.0% 96.6% 93.7% 79.2% 97.5 ％ 88.9 ％ ≤ 10m/s (6 beaufort scale) 96.7% 98.3% ≥ 17m/s (8 beaufort scale) 0.21% 0.06% 0.14% 0.5% 2014-5-19 3rd US-China Meeting 18

QTT Site • RF RFI: I: S SKA-FAST AST measurement and processing stan standa dards • Most t interference are recognizable: − Measured 150 MHz ─ 13 GHz − 2 or 3-G mobile wireless communication (UHF, L, S band) − broadcast television (analog digital, VHF, UHF band) − differential rotation system of wireless satellite television (UHF, C band) − satellite navigations 2014-5-19 3rd US-China Meeting 19

Science Goal Astr Astronomy • Molecular spectra observations • High precision pulsar timing • Active galactic nuclei • Dark matter NASA/GSF • VLBI astrometry, astro-dynamics and space C VLBI • Sky survey: detecting organic molecule and sulphur chain molecule Applic icatio ation • VLBI orbit measurement for space exploration • Pulsar time standard • Deep space pulsar autonomous navigation 2014-5-19 3rd US-China Meeting 20

Science Goal High precision pulsar timing (Lyne, 2010) 2014-5-19 3rd US-China Meeting 21

Science Goal Grav avit itat ational al w wav ave de dete tect ction NANOGrav, IPTA, PPTA Best: ~50 ns PSR J1744-1134, polarization correction, residual reduces from 487 to 195ns 20cm 50cm PSR J1045-4509, DM correction, reduces residual by ~50% 2014-5-19 3rd US-China Meeting 22

Science Goal • Follow up up obs. s. o of f FAS AST p puls ulsar ar sur survey y • Sp Spectrum sur survey at y at 6mm & & 3mm 2014-5-19 3rd US-China Meeting 23

Technique Schemes Gen ener eral • Structure design: high antenna efficiency • Servo control: accurate pointing • Active surface: quasi closed-loop control • Track: welded track + heavy load • Structure and electronics: temp under － 30 ℃ • Rx: wide band feed • Multi- beam / PAF 5m 2 , 2856 12.5m 2 , 888 15 ° 15 ° ring1…… ring22 2014-5-19 3rd US-China Meeting 24

Technique Schemes Tele lesc scope e effici fficiency – Conformal design – Homology design – Active surface Aperture efficiency Gain (K/ Jy) Frequency (GHz) 2014-5-19 25 3rd US-China Meeting

Technique Schemes Activ Active sur surfa face • Deformation: – Gravity, thermal, temperature drifting, wind load • FEM to Quick measurement: OOF • Closed-loop control GBT ： 25mins at Q-band 25m 2014-5-19 3rd US-China Meeting 26

Technique Schemes Wheel-track antenna mount: 4 or 6 feet support Max. load 2014-5-19 3rd US-China Meeting 27

Technique Schemes 60 50 Segmented main surface 40 – Single joint, 27 rings, ～ 4000@4m 2 30 20 – Secondary joint 10 0 0 10 20 30 40 50 60 2x2-1 strut Panel : Back sub-truss 1:1.53 2x2-2 strut 1:1.27 1x3 strut 1x2 strut 2014-5-19 3rd US-China Meeting 28

Technique Schemes Pointing correction • Thermal deformation • Temperature deformation • Wind load 2014-5-19 3rd US-China Meeting 29

Technique Schemes Telescope control Low speed Increase the resonance frequency large torque Increase the rigidity, reduce structure drive transmission impassable range Digital control Reduce the systematic and random error of sys servo system PI regulator+ Compound control Front feed compound control(FF)+ technique LQG 2014-5-19 3rd US-China Meeting 30

Technique schemes Welde lded w d whe heel tr l track ack – Heavy load: ~5000 ton – Temperature range － 30—+30 ℃ 2014-5-19 3rd US-China Meeting 31

Technique Schemes Sub Sub-refl flecto ctor – carbon fiber – 6-pole adjust system – Rotate to change Rx 2014-5-19 3rd US-China Meeting 32

Technique schemes Ultra-wideband feed – Increase S/N – Simultaneous multi spectrum line obs. Four ridge feedBW: 10 octave ELEVEN feed band • Simplify structure • Better radiation pattern • Compact, low cost • High-pass filter • Stable phase center • Constant beam width 2014-5-19 3rd US-China Meeting 33

Technique Scemes Soft ftwar are 2014-5-19 3rd US-China Meeting 34

Progress • Leading group by Nuer Baikeli (Chairman of XJ) Bai Chunli (President of CAS) • Leading group office / Site headquarters Liu Hua (secretary of XJ government) 2014-5-19 3rd US-China Meeting 35