MHz 10 MHz Mbps 1 C 2(a) 4 GHz MHz 56 Msps 70 MHz 70 MHz 23 MHz 14 MHz 23 MHz 2(b)

2011 32 ANNALS OF SHANGHAI OBSERVATORY ACADEMIA SINICA No. 32, 2011 1,2,3 1 2,3 2,3 2,3 2 1 1 ( 1. 200030 2. 100094 3. 100094 ) V474 1 (CEI) ( VLBI ), CEI 100 nrad ( 50 km) CEI 10 100 km 2 2 2 CEI [1] NASA (DSN) 20 80 CEI [2 5] 3.6 10 4 km 0.1 20 80 ESA 19 1 2 4 0.2 2 0.1 1 2 0.1 [6] 2011-06-27 2011-08-01, (11073048) (10PJ1411700) Shanghai Key Laboratory of Space Navigation and Position Techniques (Y054262001) (SFDLHZ2010002)

32 169 2 1 105 2 1 2 30 70 MHz 10 MHz 2 2 2 2 56 Mbps 1 C 2(a) 4 GHz 1 2 23 MHz 56 Msps 70 MHz 70 MHz 23 MHz 14 MHz 23 MHz 2(b)

170 2011 2 3 3.1 2 2 2 x 1 (t) x 2 (t) 1 2 X 1 (jω) = F (x 1 ) X 2 (jω) = F (x 2 ) i S i (ω) = X i 1(ω) X i 2(ω) S i (ω) = Ae jφ(t,ω) φ(t, ω) 2 2π 3.2 [7] φ(ω, t) = φ 0 (ω 0, t 0 ) + φ ω (ω ω 0) + φ t (t t 0). τ pd = φ 0 ω 0, τ gd = φ ω, τ pd = 1 φ ω 0 t 3.3.

32 171 2 [8] 4 4.1 2 FFT 3(a) τ = φ 2π f 1 500 f = NF F T 500f s, (1) f NF F T F F T f s n bit = τ/t sample 8 8 bits 3(b) 3(b) 3(c) 3(d) 3(c) 10 3(d) 100 3 f1 f2 f3 f1 f3 f2 3 F F T 100 500 800 1200 1400 1800 300 1000 1600 3(d) 4.2 4 3 19.6 rad/s 1000 ns

172 2011 3 ( ) ( ) F F T 4096 4 3 -

32 173 1 s 1 (t) = exp(j2πft) 2 s 2 (t) = exp[j2πf(t + τ)] 1 s 1 (t) = exp[j(2π(f f LO1 )t 2πf IM1 τ inst1 )] 2 s 2 (t) = exp[j(2π(f f LO2 )t + 2πfτ 2πf IM2 τ inst2 )] 1 2 φ(t) = 2π(f LO1 f LO2 )t + 2πfτ + 2πf IM1 τ inst1 2πf IM2 τ inst2 φ(t) = 2π f LO + 2πf τ + φ IM 2 2 f LO = φ(t)/2π = 19.567/2π = 3.114 Hz 2 3.16 Hz 10 Hz 2 σ τ = f LO t int /f BW 0.02 s 10 MHz 6 ns 1 s 10 MHz 0.1 ns f LO < 1 mhz 0.1 mhz 2 2 f1 f3 f1 f2 5 f1-f3 f1-f2 5 f1 f3 2 f1 f3 5 f1-f2/f1-f3 f1 f2 f1 f2 4.3 3 3 3 6(a) f3 1400 1600 1600 1800 f1 f3 2 f1 f3 6(b)

174 2011 f1+f3 f2 6(c) 0.73 s 100 6(d) 6 3 4.4 f1 f3 f2 7(a) f1 f2 f1 f3 7(b) 2 7(a) (b) 15 min 400 ps 7ps 7ps f2 4 f21(800 900)

32 175 7 f22(900 1000) f23(1000 1100) f24(1100 1200) 4 8 f2 8(a) f2 ns ns 3 f21 f22 f23 4 f24 f2 f2 f2 3 f21 f2 f1 8(b) 8(b) 7(a) 7(b)

176 2011 4.5 - RMS f22-f23 2 9 3 10(a) 9 f2 (a) (b) 2010-04-21 8.169 11 (c) (d) 9.014 3 (e) (f) 10.002 6 10(b) 9 4 GHz 3.6 2.5 ps ps

32 177 10 5 VLBI 2 2 0.1 mhz 1 ps 100 m CEI 100 m 10 km 1 m 10 km 10 m

178 2011 1 m 1 2 m 10 m [1]., 2003, 4: 20 [2] Edwards C D. Short Baseline Phase Delay Interferometry, TDA Progress Report 42-91, 1987 [3] Edwards C D. The effect of spatial and temporal wet-troposphere fluctuations on connected element interferometry, TDA Progress Report 42-97, 1989 [4] Thurman S W. Galileo earth approach navigation using connected-element interferometer phase-delay tracking, TDA Progress Report 42-100, 1990 [5] Thurman S W, Badilla G. Using connected-element interferometer phase-delay data for Magellan navigation in Venus orbit, TDA Progress Report 42-100, 1990 [6],,., 2009, 30(3): 967 [7] Sovers, O. J., Fanselow, J. L., and Jacobs C. S. Reviews of Modern Physics, 1998, 70(4): 1393 [8] Liu Q, Kikuchi F, Goossens S et al. J Geod Soc Jpn, 2009, 55: 243 The Wide Band Signal Process and Analysis of the Collocation Geostationary Satellite in Connected-element Interferometry System CHEN Ming 1,2,3, LIU Qing-hui 1, TANG Ge-shi 2,3, CHEN Lue 2,3, LI Li 2,3, SHAO Hua 2, ZHAO Rongbin 1, DAI Zhiqiang 1 (1. Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030; 2. Beijing aerospace control center Bejing 100094; 3. National Key Laboratory of Science and Technology on Aerospace Flight Dynamics, Beijing 100094) Abstract: The orbit resource of the geostationary satellite is becoming scarce with the increase of the human s space activity. The technology of multi-satellite sharing one orbit area is used. In the collocation satellites observation, the safety among the satellites is one of the most important problems that need to be solved. Three-way ranging measurement is always used. But it needs a long period of observation in order to get an accurate orbit. The differential phase delay can be obtained with high accuracy in connected-element interferometry. This kind of observable can give strong constraints in the plane-of-sky. One connected-element system is constructed and the data processing method is shown. The key technology of the data processing and the instrument are also described. Key words: Connected-element interferometry; collocation geostationary satellites; samebeam interferometry; differential phase delay