Post on 30-Dec-2015
description
transcript
Zdr for chosen spectral coefficients in 5-7-2004, clear-air, day time, south wind,
insects, clutter.
S.Bachmann
-60 -40 -20 0 20 40 60-50
-40
-30
-20
-10
0
10
20Complex spectrum @23.5 km
HorizontalVertical
Spectrum
oneoneelevation scanelevation scan
az
N = 1..360
IQ
Radial 1
Radial N
Radial az
Zdr
128 pulses
- - Horizontal Vertical
H V
-60 -40 -20 0 20 40 60-50
-40
-30
-20
-10
0
10
20Complex spectrum @23.5 km
HorizontalVertical
Spectrum
oneoneelevation scanelevation scan
az
N = 1..360
IQ
Radial 1
Radial N
Radial az
Zdr
128 pulses
- - Horizontal Vertical
H V
Get rid of DC
I 'Q'
M
i
iii M
III
1
M
i
iii M
QQQ
1
Estimate Spectral CoefSC=f(az, v)
0 50 100 150 200 250 300 35040
50
60
70
80
90
Azimuth, degree
Velo
city,
Spec.
coef.
# Center of the "Hump" of Spectral Coefficients
header
Center of Spectral Coef.
GCF
Window
Spectral observation
Window
-60 -40 -20 0 20 40 60-50
-40
-30
-20
-10
0
10
20Complex spectrum @23.5 km
HorizontalVertical
Spectrum
oneoneelevation scanelevation scan
az
N = 1..360
IQ
Radial 1
Radial N
Radial az
Zdr
128 pulses
- - Horizontal Vertical
H V
Get rid of DC
I 'Q'
M
i
iii M
III
1
M
i
iii M
QQQ
1
Estimate Spectral CoefSC=f(az, v)
0 50 100 150 200 250 300 35040
50
60
70
80
90
Azimuth, degree
Velo
city,
Spec.
coef.
# Center of the "Hump" of Spectral Coefficients
header
Center of Spectral Coef.
GCF
Window
v, h)
2 4 6 8 10 12 14 160
0.25
.5
.75
1
1.25
1.5
1.75
2
2.25
2.5
2.75
Velocity, m s-1
Hei
ght,
km
Sounding: Norman 12Z 7 May
wind velocityrelh, %/10mixr, g/kg
0 20 40 60 80 100 1200
0.5
1
1.5
2
2.5
3
Spectral Coefficient #
Hei
ght,
km
Center of Spec.Coef. corresponding to max velocity
Spectral observation
Sounding
Zdr
for the original spectrum (all 128 pulses included in calculations)
for the chosen spectral window (21 pulses), s.t.
the center of spectral window assumes sin- azimuthal dependence
for the chosen spectral window (21 pulses), s.t.
the center is chosen in agreement with azimuthal and height dependence from sounding.
0.5°
1.5°
2.5°
all 128 pulses window 21 pulses original GSf GSf, DCf, f(h) GSf, DCf
sounding gives v@h. High Zdr vanish at second layer (circled) - birds
128, GSf window, GSf, DCf, f(h) window, GSf, DCf
0 20 40 60 80 100 120-40
-30
-20
-10
0
Spectra: range gates 110 - 250
0 50 100 150 200 250 300 350 400 450-10
-5
0
5
10
15
Zdr
, Fdp
(rad.) and phv
(x10) for points [40:55]
Zdr
Fdp
|rhv
|0 20 40 60 80 100 120
-40
-30
-20
-10
0
Spectra: range gates 110 - 250
0 50 100 150 200 250 300 350 400 450-10
-5
0
5
10
15
Zdr
, Fdp
(rad.) and phv
(x10) for points [40:55]
Zdr
Fdp
|rhv
|0 20 40 60 80 100 120-40
-30
-20
-10
0
Spectra: range gates 110 - 250
0 50 100 150 200 250 300 350 400 450-10
-5
0
5
10
15
Zdr
, Fdp
(rad.) and phv
(x10) for points [40:55]
Zdr
Fdp
|rhv
|
4.5°
2.5°
1.5°
0 20 40 60 80 100 120-40
-30
-20
-10
0
Spectra: range gates 110 - 250
0 50 100 150 200 250 300 350 400 450-10
-5
0
5
10
15
Zdr
, Fdp
(rad.) and phv
(x10) for points [40:55]
Zdr
Fdp
|rhv
|
0.5°
GCf, DCfWindow(40-55)
180°
0 50 100 150 200 250 300 350 400 450-20
-15
-10
-5
0
5
10
15
207-pt. av., no GC: radial 000o, cut 2
Zdr1..128
Zdr40..55
Fdp1..128
-5
Fdp40..55
-5
Rhv1..128
x10+5
Rhv40..55
x10+5
0 32 64 96 128-30
-25
-20
-15
-10
-5
0Spectrum @ gate 140, radial 0o, el. 1.5o
0 32 64 96 128-30
-25
-20
-15
-10
-5
0
Pulse #
HV
HV
Spectrum @ gate 168, radial 0o, el. 1.5o
Zdr window < Zdr 128
0 50 100 150 200 250 300 350 400 450-20
-15
-10
-5
0
5
10
15
207-pt. av., no GC: radial 180o, cut 2
Zdr1..128
Zdr40..55
Fdp1..128
-5
Fdp40..55
-5
Rhv1..128
x10+5
Rhv40..55
x10+5
more Birds/insects/both? If Zdr birds (-1..4), insects (0..10)
75..95
75..95
0 50 100 150 200 250 300 350 400 450
-20
-15
-10
-5
0
5
10
15
207-pt. av., no GC: radial 180o, cut 2
Zdr1..128
Zdr40..55
Fdp1..128
-5
Fdp40..55
-5
Rhv1..128
x10+5
Rhv40..55
x10+5
from Ryzhkov: Biological scatterers in atmosphere
Insects Birds
Z (dBZ)
5 – 20 5 – 30
ZDR
(dB) 0 – 12 -2 – 3
ρhv 0.5 – 0.8
δ (°)0 – 120
0 – 40
KDP (°/km) Low & noisy
1
0.5
0
ρhv
0
δ