WVRGPS 0
GPSWVR RAOBs ( Radiosonde Observation ) WVR GPS PW LWP GPSWVR RAOBs WVR GPS WVR
.....III.....IV 1 3 2-1WVR.3 2-1-1...3 2-1-2 7 2-1-3 8 2-2GPS.9 2-2-1GPS 9 2-2-2GPS 9...12 3-1..12 3-2..14 3-3..15 3-3-1WVR 15 3-3-2..18
..20 4-1.20 4-2 PW LWP.26 4-3....32 4-4GPSWVR RAOBs.52...67.....69
3-1WVR.13 3-21998 345..19 4-11997..21 4-21998 345.21 4-3 T b..27 4-4 Tau..27 4-5 Tb.28 4-6 Tau...28 4-7WVR PW.34 4-8 WVRGPS RAOBs..59 4-9 WVRGPS RAOBs..59 4-10 WVRGPS RAOBs 59 4-11.62 4-12.62 4-13.65 4-14 Lamont...65 4-15. 66
2-1.4 2-2.4 2-3.5 3-1WVR-1100...12 3-2...13 3-3...14 4-11998 3 A 3 B C D E F T s T m..23 4-21998 4 A 4 B C D E F T s T m..24 4-31998 5 A 5 B C D E F T s T m 25 4-41998 3 9 3 18 PW LWP 29 4-51998 4 10 4 27 PW LWP.. 30 4-61998 5 5 5 31 PW LWP 31 4-71998 3 WVR PW.35 4-81998 4 WVR PW.36 4-919985 WVR PW.. 37 4-101998 3 15 WVR 30 ()23.8 GHz ()31.4 GHz.....38 4-111998 3 15 WVR 60 ()23.8 GHz ()31.4 GHz.....39 4-121998 3 15 WVR 90 ()23.8 GHz ()31.4 GHz.....40 4-131998 3 15 WVR ()30 ()60 ()90.41 4-141998 4 12 WVR 30 ()23.8 GHz ()31.4 GHz.....42 4-151998 4 12 WVR 60 ()23.8 GHz ()31.4 GHz.....43 4-161998 4 12 WVR 90 ()23.8 GHz ()31.4 GHz.....44 4-171998 4 12 WVR ()30 ()60 ()90.45 4-181998 5 25 WVR 30 ()23.8 GHz ()31.4 GHz.....46 4-191998 5 25 WVR 60 ()23.8 GHz ()31.4 GHz.....47
4-201998 5 25 WVR 90 ()23.8 GHz ()31.4 GHz.....48 4-211998 5 25 WVR ()30 ()60 ()90.49 4-223 16 08:00.50 4-233 16 WVR PW LWP...51 4-24 WVRGPS RAOBs 55 4-25 WVRGPS RAOBs...56 4-26 WVRGPS RAOBs...57 4-27RAOBs()WVR()GPS()1998 3 5 (a) Total (b) Rainfall event ( > 0.1mm) (c) Rainfall event ( < 0.1mm) (d) maximum....58 4-28GPS()WVR()RAOBs() 60 4-29WVR-RAOBs()GPS-RAOBs()WVR-GPS() 61 4-301998 345 GPSWVR RAOBs (a)wvr-raobs (b)wvr-raobs (c)gps-raobs (d)gps-raobs (e)wvr-gps (f)wvr-gps..63 4-31WVR-RAOBsGPS-RAOBs WVR-GPS..63 4-32 Lamont WVRGPS RAOBs (a)wvr-raobs (b)wvr-raobs (c)gps-raobs (d)gps-raobs (e)wvr-gps (f)wvr-gps.64 4-33 Lamont WVR-RAOBsGPS-RAOBs WVR-GPS...64
( Precipitable Water ; PW ) WVR (Global Position System ; GPS) ( ) GPS GPS Radiometrics Corporation ( WVR ) [7] [8][23][24][25]
2-1WVR 2-1-1 Chandrasekhar ( 1960 ) I ν I ν 2-1 di ds ν = I κ ν e + S ( 2-1 ) S ( source function )κ e s
2-1 [20] Kirchoff κ a κ e S S a ν = κ B (T ) ( 2-2 ) B ν (T) Planck B ν 3 2 hν 1 ( T ) = 2 / kt c e h ν 1 ( 2-3 ) h Planck k Boltzmann c ν B ν (T) 2-2 B ν (T) = I ν
圖 2-2 表面亮度與輻射強度關係的示意圖[20] 綜合以上的推論 將(2-2)式帶入(2-1)式並求解(2-1)式 得到的 一般解 即為初步的輻射傳送方程式 I (0 ) = I ( s ) e ν ν τ ( s0 ) 0 + B (T ) e s0 ν 0 κ ds τ ( s) a ( 2-4 ) 其中 τ 為光程( optical depth ) τ ( r1, r 2 ) = r2 r1 κ a dr ( 2-5 ) 在(2-4)式中 s 0 為起始點的位置 等號右邊第一項表示大氣邊界層 的貢獻量 第二項為從邊界層到觀測位置之間路徑上的貢獻量 如 圖 2-3 圖 2-3 輻射傳遞路徑圖[20]
Rayleigh-Jeans hν << kt Planck 2 2ν kt 2kT B ν ( T ) = ( 2-6 ) 2 2 c λ λ (2-6) ( T )Planck ( B ν (T) ) ( Brightness TemperatureT b ) 2 λ T b ( ν ) I ν ( 2-7 ) 2k (2-4) T b ( ν ) τ ( s ) s T ( s ) 0 0 τ ( s ) = T ( ν ) e + e κ ds b 0 ( 2-8 ) 0 a R ( ν, T ( s )) T b0 (ν) R 2 1 / R( ν kt kt hν kt, T ) = ( e 1) 2 λ B ( T ) hν ( 2-9 ) ν R(ν,T) hν/kt
1 hν 1 hν R ( ν, T ) = 1 + [ ] + [ ] 2 +... ( 2-10 ) 2! kt 3! kt Rayleigh-Jeans R = 1 (2-8) Radiative Transfer Equation RTE T b ( ν ) = τ ( s0 ) s0 T e + 0 T ( s) e b 0 τ ( s ) κ a ds ( 2-11 ) T b0 = 2.7 K 0 s 0 2-1-2 T P ρ v κ a ( H 2 O ) ( O 2 ) κ + κ a =.15κ O + 1. 08κ 2 H 2O 1 ( 2-12 ) L 1.15 1.08 Keihm [1992]
22.235 GHz( )183.31 GHz( ) Liebe [1987] 50 GHz 70 GHz 118.8 GHz [Rosenkranz 1975]
2-2GPS 2-2-1GPS GPS 24 6 60 55 20200 11 58 GPS [7] 2-2-2GPS GPS 1575.42 MHz (L1)1227.6 MHz (L2) GPS i i i i i i L = ρ I + ρ + cδ cδ + λn 1k k k k k 1 ( 2-16 ) 1k f 2 i i 1 i i i i L ρ I + ρ + cδ cδ + λ n 2k k 2 k k k 2 2k = ( 2-17 ) f 2 L L1 L2 ρ I 1575.42 MHz δ k δ i
( k ) ( i ) λ n GPS L1 2 f1 ρ = I ( 2-18 ) I 2 f 2 L 1 2 2 = ( f L f ) ( 2-19 ) 2 2 1 1 2 2 f f 3 L 1 2 [8] ij L 3kl i i j j = L L ) ( L L ) ( 2-20 ) ( 3k 3l 3k 3l [8] D Z m ( θ) + Z m ( θ) = ( 2-21 ) w w h h Z m ( Zenith Wet Delay ; ZWD )Z h ( Zenith Hydrostatic Delay ; ZHD )θ m w (θ)m h (θ)
ZWD ZHD ( Mapping Function ) Hopfield [17] 12 m w (θ) m h (θ) [13] ( k, l ) dd dd = Z m θ ) Z m( θ ) ( 2-22 ) k ( k l l Z k Z l ( k, l ) θ k θ i (2-22) dd = Z Z ) m( θ ) ( 2-23 ) ( k l l m(θ k )m(θ l ) [24]
3-1 Radiomatrics ( Water Vapor and Liquid Water RadiometerWVR ) WVR-1100 3-1[25] 23.8 GHz 31.4 GHz 23.8 GHz ( 22.235 GHz ) (pressure broadening) (down-link transmissions) ( Precipitable Water ) 31.4 GHz 3-1WVR-1100 [25]
3-2 [25] Instrument function or parameter Sample time functions Beam width Accuracy Resolution Radiometric range User selectable for all instrument 5.7 & 4.4 degree 0.3 K 0.25 K 0 K ~ 700 K Operating range -20C ~ +50C Power requirements condi- Voltage requirements Output Dimensions 120 watts maximum ( cold operating tions ) 3-1WVR [25] 90-130 or 180-260 vac, 50 to 440 Hz Rs-232 at 1200 baud, n, 8, 1, to notebook Computer, ASCII data files 50x28x76 cm
3-2 3-3 WVR 0 ( ) 180 ( 15 165 15 [2] ( ) GPS WVR Raob GPS 3-3
3-3 3-3-1WVR [15] (92 %94 % 98 %) 98 % [2] 98 % ( Tb )PW LWP [1] PW = A0 + A i Tb i i ( 3-1 ) LWP = B0 + B i Tb i i ( 3-2 ) A 0 B 0 A i B i i Tb τ PW LWP
PW = C 0 + τ i C i i ( 3-3 ) LWP = D 0 + τ i D i i ( 3-4 ) C 0 D 0 C i D i τ i (2-12) [20] ext T = T e τ + T (1 e τ b b mr ) ( 3-5 ) T mr (mean radiating temperature) [20] T mr = 0 0 α Te α e s 0 s α dt 0 α dt ds ds ( 3-6 ) (3-5) ext Tmr Tb τ ( db) = 3.43 ln ( 3-7 ) Tmr Tb [22]
WVR Tb WVR ( PW ) ( LWP ) ( T 0 ) ( Vd 0 ) ( P 0 ) [1] PW = LWP = A 0 B + A Tb + 0 i + B Tb i i i i i A i+ 1 + B T i + 1 0 T + 0 A i + 2 + B Vd i+ 2 0 Vd + 0 + A i + 3 B P i+ 3 0 P 0 ( 3-8 ) 2 WVR PW 1 0.1 0.25 [1] X 0 j j ( j) = A + A Tb ( 3-9 ) i i i X(j) j ( ) A j 0 A j i (3-8)
3-3-2 GPS ZWD ZWD PW [23] PW = ZWD ( 3-10 ) 8 10 = ( 3-11 ) ρ R [( k / T ) k ' ] + v 3 m 2 R v (J/Kg-k)k 3 3.793±0.012 10 5 (K 2 /mb) ρ k 2 22.1±2.2 (K/mb)T m T m = ( P / T ) dz v 2 ( P / T ) dz v ( 3-12 ) P v (mb)t (K) 0.15 20% [10] [Liou et al. 2000b] 1997 1998 586 0.153 0.166 0.159 0.0022 GPS
T s [Bevis et al. 1992] [23] T a + b = ( 3-13 ) m T s a b 3-2 a b March 24.4 0.89 April 91.1 0.65 May 62.4 0.75 3-21998 345
WVRGPS GPSWVR RAOBs 4-1 ( Temperature Inversion ) WVR GPS
( T s ) ( T m ) T s T m 2 1997 3 4-1 1998 345 T s T m R R 22.9 % 1998 3 R 0.883 0.928 5.2 %
Month Raobs Jan 42 6 4 2 Feb --- --- --- --- Mar 62 14 5 2 Apr 60 8 5 4 May 59 2 10 0 Jun 60 0 4 0 Jul 62 1 11 0 Aug 62 1 4 0 Sep 60 5 5 2 Oct 62 6 4 2 Nov 60 9 3 1 Dec 62 5 4 2 4-11997 March 0.89 0.88 0.93 5.2 April 0.61 0.54 0.68 22.9 May 0.80 0.73 0.76 4.6 4-21998 345
4-11998 3 A 3 B C D E F T s T m
4-21998 4 A 4 B C D E F T s T m
4-31998 5 A 5 B C D E F T s T m
4-2 PW LWP T b τpwlwp (3-1) (3-2)(3-3)(3-4) PW LWP PW LWP PW LWP 4-24-3 T b PW LWP 4-44-5 τ T b PW 4 11 LWP 4 12 4 WVR PW LWP 4-44-54-6 1998 3 9 3 18 4 10 4 27 5 PW LWP
Month PW0 PW1 PW2 Mean Rmsd, cm Jan -0.239 0.096-0.059 2.924 0.127 Feb -0.231 0.096-0.058 3.136 0.149 Mar -0.332 0.097-0.058 3.655 0.150 Apr -0.531 0.101-0.060 4.249 0.174 May -0.874 0.105-0.059 5.061 0.143 Jun -1.059 0.108-0.062 5.572 0.144 Jul -1.090 0.107-0.057 5.524 0.104 Aug -1.118 0.107-0.056 5.636 0.121 Sep -1.035 0.108-0.062 5.284 0.140 Oct -0.634 0.101-0.058 4.419 0.115 Nov -0.413 0.097-0.055 3.643 0.082 Dec -0.203 0.094-0.057 3.113 0.136 4-3 Month PW0 PW1 PW2 mean Rmsd,cm Jan 0.069 21.84-12.93 2.924 0.0487 Feb 0.080 21.72-12.87 3.136 0.0486 Mar 0.094 21.47-12.65 3.655 0.0538 Apr 0.070 21.46-12.63 4.249 0.0688 May 0.086 21.15-12.36 5.061 0.0587 Jun 0.055 21.11-12.26 5.572 0.0598 Jul 0.112 21.05-12.56 5.524 0.0840 Aug 0.166 20.69-12.08 5.636 0.0759 Sep 0.048 21.22-12.42 5.284 0.0710 Oct 0.129 20.94-12.23 4.419 0.0380 Nov 0.129 21.07-12.33 3.643 0.0460 Dec 0.139 21.21-12.51 3.113 0.0460 4-4
Month LWP0 LWP1 LWP2 Mean Rmsd,µm Jan -423.87-11.39 39.09 272.80 158.8 Feb -524.31-9.46 38.3 423.05 233.02 Mar -493.84-11.6 40.64 402.95 214.72 Apr -458.2-15.04 45.98 247.26 256.02 May -287.51-21.84 55.15 262.18 201.41 Jun -397.71-22.27 59.06 205.44 215.06 Jul -266.41-19.0 48.51 84.10 228.35 Aug -270.88-22.78 56.77 140.31 198.45 Sep -273.12-21.6 54.32 167.80 213.98 Oct -344.06-19.7 52.58 148.42 163.62 Nov -362.26-16.98 47.73 122.79 172.42 Dec -538.11-10.55 41.57 246.80 270.2 4-5 Month LWP0 LWP1 LWP2 mean Rmsd, µm Jan -166.19-2036.61 6670.8 272.80 55.94 Feb -165.78-2058.26 6722.99 423.05 82.8 Mar -192.96-2013.61 6868.08 402.95 84.67 Apr -177.4-2200.56 7067.44 247.26 91.38 May -196.07-2310.99 7472.7 262.18 111.51 Jun -200.75-2333.73 7428.54 205.44 93.78 Jul -122.75-2465.65 7092.21 84.10 125.36 Aug -239.06-2210.16 7359.84 140.31 107.81 Sep -186.31-2363.3 7403.16 167.80 107.89 Oct -170.9-2375.37 7390.2 148.42 75.82 Nov -150.92-2423.72 7328.28 122.79 48.92 Dec -157.05-2093.64 6730.13 246.80 61.99 4-6
4-41998 3 9 3 17 PW LWP
4-51998 4 11 4 26 PW LWP
4-61998 5 6 5 31 PW LWP
4-3 30 ( Tb ) 60 PW 4-74-84-9 1998 34 5 PW 4-7 60 90 0.447 cm 30 60 2.035 cm 30 90 2.482 cm 30 5 4-104-11 4-12 30 60 90 1998 3 15 19:00 ~ 24:00 4-13
PW 4 5 4-14 4-16 4 12 9:00 ~ 14:00 4-18 4-20 5 25 12:00 ~ 17:00 4-17 4-21 PW 3 4-22 1998 3 16 4-23 WVR WVR PW
30 PW mean(cm) 60 PW mean(cm) 90 PW mean(cm) 30 &60 30 &90 60 &90 March 6.012 3.977 3.53 2.035 2.482 0.447 April 6.744 4.352 3.83 2.392 2.914 0.522 May 8.648 5.75 5.10 2.898 3.548 0.650 4-7WVR PW
4-71998 3 10 3 31 PW
4-81998 4 1 4 28 PW
4-91998 5 6 5 31 PW
4-101998 3 15 WVR 30 ()23.8 GHz ()31.4 GHz LST = Local Standard Time
4-111998 3 15 WVR 60 ()23.8 GHz ()31.4 GHz
4-121998 3 15 WVR 90 ()23.8 GHz ()31.4 GHz
4-131998 3 15 WVR ()30 ()60 ()90
4-141998 4 12 WVR 30 ()23.8 GHz ()31.4 GHz
4-151998 4 12 WVR 60 ()23.8 GHz ()31.4 GHz
4-161998 4 12 WVR 90 ()23.8 GHz ()31.4 GHz
4-171998 4 12 WVR ()30 ()60 ()90
4-181998 5 25 WVR 30 ()23.8 GHz ()31.4 GHz
4-191998 5 25 WVR 60 ()23.8 GHz ()31.4 GHz
4-201998 5 25 WVR 90 ()23.8 GHz ()31.4 GHz
4-211998 5 25 WVR ()30 ()60 ()90
4-223 16 0800 [ ] 1022 33 127 1617
4-233 16 WVR PW LWP
GPSWVR GPS [2223] WVR ( Quality Control ; QC ) ( > 0.1 mm ) ( < 0.1 mm ) WVR PW GPS 4-15 4-244-254-26 QC WVR GPS QC WVR 4-27 QC 4-84-9 4-10
PW 3 ~ 5 WVR GPS PW WVR GPS 4-284-29 GPS 4-11 4-12 WVR GPS 3 ~ 4 cm 4 ~ 5 cm 5 ~ 6 cm WVR GPS WVR - RAOBs GPS RAOBs WVR GPS PW RAOBs WVR GPS 170 3000
4000 WVR GPS WVR - RAOBs GPS - RAOBs RAOBs PW RAOBs WVR - GPS WVR 4-30 4-31 4-13 2 ~ 3 cm WVR GPS 4 cm PW WVR - GPS Lamont 4 ~ 6 4-324-33 4-14
4-24 WVRGPS RAOBs
4-25 WVRGPS RAOBs
4-26 WVRGPS RAOBs
4-27RAOBs()WVR()GPS()1998 3 5 (a) Total (b) Rainfall event ( > 0.1mm) (c) Rainfall event ( < 0.1mm) (d) maximum
WVR GPS RAOBs W-R G-R W-G Mean SD Mean SD Mean SD rmsd rmsd rmsd March 3.53 1.16 3.21 0.85 3.79 0.61 1.30 0.93 0.88 April 3.83 1.30 3.92 1.20 4.63 0.87 1.38 0.91 0.96 May 5.10 1.35 5.14 1.00 5.54 0.64 1.55 0.79 1.17 4-8 WVRGPS RAOBs WVR GPS RAOBs W-R G-R W-G Mean SD Mean SD Mean SD rmsd rmsd rmsd March 3.19 0.74 3.21 0.85 3.79 0.61 0.98 0.93 0.56 April 3.56 1.05 3.92 1.20 4.63 0.87 1.09 0.91 0.75 May 4.76 0.99 5.14 1.00 5.54 0.64 0.88 0.79 0.88 4-9 WVRGPS RAOBs WVR GPS RAOBs W-R G-R W-G Mean SD Mean SD Mean SD rmsd rmsd rmsd March 3.13 0.58 3.18 0.80 3.79 0.61 0.39 0.54 0.37 April 3.52 1.00 3.90 1.12 4.63 0.87 0.61 0.77 0.60 May 4.67 0.75 5.13 0.93 5.54 0.64 0.57 0.47 0.53 4-10 WVRGPS RAOBs
4-28GPS()WVR()RAOBs()
4-29WVR-RAOBs()GPS-RAOBs()WVR-GPS()
WVR GPS RAOBs 0 ~ 0.5 --- --- --- 0.5 ~ 1 --- --- --- 1 ~ 1.5 55 79 --- 1.5 ~ 2 102 130 --- 2 ~ 2.5 117 139 2 2.5 ~ 3 363 305 7 3 ~ 3.5 676 497 12 3.5 ~ 4 544 464 23 4 ~ 4.5 626 423 30 4.5 ~ 5 627 459 23 5 ~ 5.5 381 318 26 5.5 ~ 6 156 214 30 6 ~ 6.5 38 150 12 6.5 ~ 7 10 46 5 4-11 WVR-RAOBs GPS-RAOBs WVR-GPS -3 ~ -2.5 1 2 1-2.5 ~ -2 2 5 7-2 ~ -1.5 3 7 19-1.5 ~ -1 28 35 81-1 ~ -0.5 49 55 427-0.5 ~ 0 35 43 1637 0 ~ 0.5 7 16 1118 0.5 ~ 1 3 1 271 1 ~ 1.5 --- --- 107 1.5 ~ 2 --- --- 21 2 ~ 2.5 --- --- 12 2.5 ~ 3 --- --- 2 4-12
4-301998 345 GPSWVR (a)wvr-raobs (b)wvr-raobs (c)gps-raobs (d)gps-raobs (e)wvr-gps (f)wvr-gps 4-31WVR-RAOBsGPS-RAOBs WVR-GPS
4-32 Lamont WVRGPS RAOBs (a)wvr- RAOBs (b)wvr-raobs (c)gps-raobs (d)gps-raobs (e)wvr-gps (f)wvr-gps 4-33 Lamont WVR-RAOBsGPS-RAOBs WVR-GPS
WVR-RAOBs GPS-RAOBs WVR-GPS PW 0 ~ 1 --- --- 7 1 ~ 2 --- --- 164 2 ~ 3 8 10 464 3 ~ 4 30 40 1157 4 ~ 5 51 50 999 5 ~ 6 37 41 676 6 ~ 7 14 14 145 4-13 WVR-RAOBs GPS-RAOBs WVR-GPS PW 0 ~ 1 262 262 2792 1 ~ 2 428 428 2675 2 ~ 3 265 265 1037 3 ~ 4 305 305 1159 4 ~ 5 146 146 550 5 ~ 6 25 25 28 4-14 Lamont
WVR GPS(5 mm) RAOBs Total number 4805 3336 170 ( no Q.C. ) Rainfall event 4048 ---- ---- ( > 0.1 mm) Rainfall event 3777 ---- ---- ( < 0.1 mm) Exclude Outliers 71 78 ---- ( Maximum ) After Q.C. 3706 3258 170 4-15
1 WVR GPS 2 WVR PW 3 1998 3 5 WVR 3 3.53 cm 5 5.10 cm GPS RAOBs ( 4-29) 4 WVR WVR RAOBs 1.5 cm 1.0 cmwvr GPS 1.17 cm 0.88 cm
5 WVR GPS ( 0.37 cm ) WVR RAOBs GPS RAOBs ( 0.390.54 cm ) WVR GPS RAOBs
[1] 2000: [2] 1999: [3] 1999: GPS WVR [4] 1988: [5] 1994: [6] 1999: WVR [7] 1999: GPS [8] Brunner, F. K., and M. Gu, 1991: An Improved Model for Dual Frequency Ionospheric Correction of GPS Observation, Manuscripta Geodaetica, 16(3), pp. 205-214. [9] Beutler, G., E. Brockman, S. Frankhauser, W Gurtner, J. Johnson, L. Mervart, M. Rothacher, S. Schaer, T. Springer, and R. Weber, 1996: Bernese GPS Software Version 4.0. Univ. of Berne, 418 pp. [10] Bevis, M., S. Businger, S. Chiswell, T.A. Hrring, R. A. Anthes, C.Rocken, and R. H. Ware, 1994: GPS meteorology: Mapping Zenith Wet Delay onto Precipitable Water. J. Appl. Meteor.,33,379-386. [11] Bevis, M., S. Businger, T. A. Herring, C. Rocken, R. A. Anthes, and R. H. Ware, 1992: GPS meteorology : Remote Sensing of Atmospheric Water Vapor Using the Global Position System.. J. Geophy. Res.., 97, 15 784-15 801. [12] Chang, A.T. C., L. S. Chiu, C. Kummerow, and J. Meng, 1999 : First Results of the TRMM Microwave Imager (TMI) Monthly Oceanic Rain Rate: Comparison with SSM/I. Geophys. Res. Lett., 26, 2 379-2 382. [13] Duan, J. P., M. Bevis, P. Fang, Y. Bock, S. Chiswell, S. Businger, C. Rocken, F. 1996: Solheim, T. Vanhove, R. Ware, S. Mcclusky, T. A. Herring, R. W. King, GPS Meteorology: Direct Estimation of the Absolute Value of Precipitable Water. J. Appl. Meteor., 35, 830-838. [14] Elgered, G., J. L. Davis, T. A. Herring, and I. I. Shapiro, 1991: Geodesy by Radio Interferometry: Water Vapor Radiometry for Estimation of the Wet Delay. J. Geophys. Res., 96, 6 541-6 555. [15] Han, Y. and E. R. Westwater, 1995: Remote Sensing of Tropospherics Water
Vapor and Cloud Liquid Water by Integrated Ground-Based Sensors, J. Atmos. Oceanic Technol., 12, 1 050-1 059. [16] Güldner, J., and D. Spänkuch, 1999 : Results of Year-Round Remotely Sensed Integrated Water Vapor by Ground-Based Microwave Radiometry. Amer. Meteor. Soc., 38, 981-988. [17] Goad, C.C., and L. Goodman, 1974: A Modified Hopfield Tropospheric Annual Refraction Correction Model in Processing of the Full Meeting of the America Geophysical Union, San Francisco, California, December 12-17. [18] Hofmann-Wellenhof, B., H. Lichtenegger, and J. Collins, 1997: Global Positioning System Theory and Practice, Springer-Verlag, Wien. [19] Hofmann-Wellenhof, B., H. Lichtenegger, and J,Collins, 1993: Global Positioning System: Theory and Practice. Springer-Verlag, pp. 326. [20] Janssen, M. A., 1993: Atmospheric Remote Sensing by Microwave Radiometry. (ed) John Wiley & Sons, Inc., New York, pp. 572. [21] Liebe, H. J., 1987 : A Contribution to Modeling Atmospheric Millimeter- Wave Properties, Frequenz, 41, 31-36. [22] Liou, Y. -A., C.-Y. Huang, and Y. -T. Teng, 2000a: Precipitable Water Observed by Ground-Based GPS Receivers and Microwave Radiometry. Earth, Planets, and Space. (in press) [23] Liou, Y. -A., Y. -T. Teng, Teresa Van Hove, and James Liljegren, 2000b: Comparison of precipitable water observations in the near tropics by GPS, microwave radiometer and radiosondes. J. Appl. Meteor. (in press) [24] Liou, Y. -A., and C.-Y. Huang, 2000: GPS Observation of PW during the Passage of a Typhoon, Earth, Planets, and Space. (in press). [25] Radiometrics WVR-1100 Instrument Manual, 1997: WVR-1100 Water Vapor and Liquid Water Radiometer. Radiometrics Corporation, Boulder, Colorado, 30 pp. [Available from Radiometrics Corporation, 2840 Wilderness Place Unit G, Boulder, CO 80301-5414, USA.] [26] Rosenkranz, P. W., and M. J. Komichak, and D. H. Staelin, 1982: A Method for Estimation of Atmospheric Water Vapor Profiles by Microwave Radiometry. J. Appl. Meteor., 21, 1 364-1 370. [27] Schroeder, J. A., and E. R. Westwater, 1991: Users Guide to WPL Microwave Radiative Transfer Software. NOAA Tech. Memo. ERL WPL-213, 84 pp. [28] Sierk, B., B. Burki, H. Becker-Ross, S. Florek, R. Neubert, L. P. Kruse, and H. Kahle, 1997: Tropospheric Water Vapor Derived from Solar Spectrometer, Radiometer, and GPS Measurements. J. Geophys. Res., 102, 22 411-22 424. [29] Solheim, F., J. R. Godwin, E. R. Westwater, Y. Han, S. J. Keihm, K. Marsh, and
R. Ware, 1998: Radiometric Profiling of Temperature, Water Vapor and Cloud Liquid Water Using Various Inversion Methods. Radio Sci., 33, 393-404. [30] Ulaby, F. T., R. K. Moore, and A. K. Fung, 1981 : Microwave Remote Sensing: Active and Passive Volume 1. Artech House Inc., Norwood. pp. 456. [31] Westwater, E. R, J. B. Snider, and M. J. Falls, 1990: Ground-based Radiometric Observations of Atmospheric Emission and Attenuation at 20.6, 31.65, and 90 GHz: A Comparison of Measurement and Theory. IEEE Trans. Antennas Propag., 38, 1 569-1 580. [32] Westwater, E. R., 1978: The Accuracy of Water Vapor and Cloud Liquid Determinations by Dual-Frequency Ground-Based Microwave Radiometry. Radio Sci., 13(4), 677-685. [33] Westwater, E. R., Y. Han, J. B. Snider, K. S. Gage, W. Ecklund, A. Riddle, J. H. Churnside, J. A. Shaw, M. J. Falls, C. N. Long, and T. P. Ackerman, 1999: Ground-Based Remote Sensor Observations During PROBE in the Tropical Western Pacific. Bull. Amer. Meteor. Soc., 80(2), 257-270.