Twenty-five years of narrowband metal resonance lidars and current trends

Chiao-Yao She, Colorado State UniversityCurrently visiting NIPR

Outline of the talk:

History: It began with temperature measurement in Europe

Doppler effect in resonance scattering (Laser Induced Fluorescence): Ph i f b d t l tt i lidPhysics for narrowband metal resonance scattering lidarsIn north America: measuring temperature and windScience example: Searching for the global mesopause thermal p g g pstructureCSU Na lidar investigating dynamics at different time scalesCurrent trends and directions on metal lidar technologiesCurrent trends and directions on metal lidar technologiesConclusion

Laser induced fluorescence: NaD2‐T‐W measurement

3 P2

3/2 (16) 0 5

0.6175 K190 KE

0.3

0.4

0.5

450 K

190 K 210 K

LU

OR

ESC

EN

C

0.1

0.2

0.3

RM

AL

IZE

D F

L

a

+–νν

ba b

3 S2

1/2

F=2(5)0

0.1

-4 -3 -2 -1 0 1 2 3 4N

OR

1/2F=1(3)

•Scanning: Spectrum → temperature

FREQUENCY SHIFT (GHz)

•RT = (I+ + I- ) / 2Ia; RW = (I+ - I- ) / Ia1nm ~ 1050 GHz; 1MHz ~ 0.6m/s

Fricke and von Zahn JATP (1985)

Historical temperature measurements Demonstration of Doppler Fricke and von Zahn, JATP (1985)Demonstration of Doppler temperature measurement via a tunable dye laserNonlinear fit to spectrum

Scan & LIF

Gibson, Thomas, and Bhattachacharyya,

Five years of science observation with a number of excellent scienceBhattachacharyya,

Nature (1979)with a number of excellent science publications plus climatoloy studies in Lübken/Zahn (1991)

Doppler Effect for LOS wind & temperature measurement with LIF works differently from that with Rayleigh scatteringLIF works differently from that with Rayleigh scattering

( ) :Cabannes Rayleigh scattering0.8

1Cabannes scattering @589 nm

G(νL, 200 K)

G( 0 17 50 / )ons

2 2(1 )rec L L

L

u uc

Frequency analysis

ν ν νλ

= − = −0.4

0.6

G(νL+0.17; 50m/s)

nesh

ape

func

tio

( )or with associated intensity

Frequency analysis0

0.2

-3 -2 -1 0 1 2 3

Lin

Freq (GHz)

00

LIF=Absorption+Re-emssion

: ;Re :a L

uAbs emissionν ν ν

λ= = − −

1

1.5Laser Induced Fluorescence

G(ν0, 200 K)

0.02*g(nL=0.4 GHz)

ctio

ns

1

1.5Laser Induced Fluorescence

G(abs;200K)0.02*g(0.4 GHz)G(abs;200K,50m/s)0 02* ( 0 4 GH )ct

ions

0

0 0 0 00

( ) 2

'

e L L

u

F l i d t k

λ

ν ν ν ν ν ν νλ

= − = − − = −0.5

1 G(ν0+0.085;50m/s)

Line

shap

e fu

nc0.5

1 0.02*g(-0.4 GHz)0.02*g(0.0 GHz)

Line

shap

e fu

nc

'in

Frequency analysis doesn t workIntensity dependent Tand LOS w d

0-3 -2 -1 0 1 2 3

L

Freq (GHz)

0-3 -2 -1 0 1 2 3

L

Freq (GHz)

2.5N

aD

2 Doppler-Free Spectrum

0.7Con_5(97.0)WTST-W Calibration Curves

2.0

2.5

rb. U

nit)

-: - 1,281.4 MHza: - 651.4 MHz+: - 21.4 MHz

0.6

+I- )/2

I a]

280K-100

m/s

0m/s

100m

/s

1 0

1.5

ence

(Ar

cν

0 4

0.5

re R

atio

[(I ++

200K

0.5

1.0

uore

sce

ν

a

b

νν ν+-

0.3

0.4

Tem

pera

tu

120K

0.0-1.5 -1 -0.5 0 0.5 1 1.5

Fl

νb

-0.4 -0.2 0.0 0.2 0.4 0.60.2

Wi d R ti [(I I )/I ]Frequency (GHz) Wind Ratio[(I+-I

-)/I

a]

We use DFS to lock the laser at •RT = (I+ + I‐ ) / 2Iaνa and AOM to get to ν+ and ν- •RW = (I+ ‐ I‐ ) / Ia

Observation Under Sunlit ConditionsSodium Faraday Filter: Rejection of sky background

Na

BP1 P2

A heated sodium cell in

axial magnetic field betweenaxial magnetic field between

two crossed polarizers

Chen et al., 1993 and 1996

100

105(e) Hourly Mean Temperature (Noon_310_205)

)

100

105(f) Hourly Mean Temperature (Night_310_205)

T2310_10.5_NT2205_9.5_N

m)

Temp – Wind Obs. by Na lidar1 8 0

A p ri l 20 0 2 (T w o m in . In t ig ra t io n )

160 170 180 190 200 210 220 230 24080

85

90

95T2310_19.5_NT2205_19.5_N

Temperature (K)

Alti

tude

(km

)

160 170 180 190 200 210 220 230 24080

85

90

95

Temperature (K)

Alti

tude

(km

1 0 0

1 2 0

1 4 0

1 6 0

1 8 0c h 4c h 4c h 4

de (k

m)

A p r 2 2 1 9 :2 9 : 1 2

A p r 2 2 1 1 :4 3 : 5 5A p r 2 2 1 1 :5 6 : 0 3

85

90

95

100(g) Hourly Mean North Wind (Noon_310_205)

V2310_19.5_NV2205_19.5_N

Alti

tude

(km

)

85

90

95

100(h) Hourly Mean North Wind (Night_310_205)

V2310_10.5_NV2205_9.5_N

Alti

tude

(km

)

0 5 0 1 0 0 1 5 0 20 0 25 0 3 0 0 3 5 0 40 020

40

60

80Altit

u

The CSU Na lidar system in 2002with two beams pointing 30o off

ith t th t th th t

CSU hourly mean profiles in summer and winter at night (right) and noon (worst case; left) with

-100 -50 0 50 10080

85

Wind (m/s)-100 -50 0 50 100

80

Wind (m/s)

0 5 0 1 0 0 1 5 0 20 0 25 0 3 0 0 3 5 0 40 0P h oto n s /1 50 m

S S i ht

zenith, one to the east, the other tothe north. Each beam has atelescope, 35 cm in diameter.

M i i f

g ( g ) ( ; )respectively measured temperature profiles (upper panels) and wind profiles (lower panels).

• Summer noonRange: 84-97kmDelta: <20K,<30m/s

• Summer nightRange: 84-100kmDelta: <2K, <3m/s

• Winter noon • Winter night

Measurement uncertainties of a scaled Na Lidar system with two 80cm diameter telescopes will be reduced by a factor ofRange: 82-98km

Delta: <5K,<10m/s

gRange: 84-100kmDelta: <1K, <2m/s

will be reduced by a factor of 2.3.

Mesopause temperature structure: Double minima?

69oN Higher alt.

Lower alt.

Lübken/Zahn (1991) @ 41oN; She et al. (1993)

States and Gardner (1998)Agree with model; She et al. (1995)

Global mesopause thermal structure

Von Zahn et al. (1996)

She et al. (2000) Mertens et al. (2000)

Tides and tidal variability – CSU Full‐diurnal Lidar Observation (raw data)

September 2003 Diurnal Cycle Observations

Convective  instability; large wind grad.

Planetary‐tidal wave interactionsNine‐day continuous observation ofTidal perturbations & variability; GWs

Planetary tidal wave interactions

She et al., GRL, 2004

Mean state (T, U, V) and GCM comparison, Fig.4 of Yuan,S,K,S,G,R,L,&S; JGR, 2008

The observed results are in qualitative agreement with our current understanding of the mesopause region thermal and dynamical structure with two level mesopausethe mesopause region thermal and dynamical structure, with two-level mesopause , zonal wind switching directions and “residual” meridional flow (SP → WP).Note: Difference from model less than that between models.

Long-term CSU lidar (1st light, Aug.,’89; regular, May ’91) Nightly average temperatures (1990 March 2010)Nightly average temperatures (1990 – March 2010)

240

260

)Nightly Mean Temperature at 87km (90-Mar10)

(a)

200

220

240

pera

ture

(K)

160

180

0 3 6 9 12 15 18 21

Tem

Time (Year starting Jan 01, 1990)

200

250

240

260Solar Flux(81-day mean; 87-May2010)

Lidar Temperature (100km; 90-Mar2010)

2 Wm

-2H

z)

Te

(b)01-01-'98

100

150

200

200

220

240

x (S

FU=1

022

emperature (

Solar Min6.49

MPE1.45

0

50

160

180

-3 0 3 6 9 12 15 18 21

F10.

7 Fl

u

(K)

Time (Years from January 1, 1990)

9.99

Main Results: Comparison between the analyses for the entire data set (1990-Mar2010) with “Pinatubo effect” accounted for (Red solid), removed (smaller red open) and ignored (large open).

10511P(90-10)7P(90-10_PR)

(b)105

Temperature Trend Comparisons

100

7P(90-10)

(km

)

100

(km

)90

95

Alti

tude

90

9511 P_(90 - 10)7 P_(90 - 10_PR)SMLTMHAMMONIA

Alti

tude

(

-8.0 -6.0 -4.0 -2.0 0.0 2.0 4.085

-3 -2 -1 0 1 2 385

Change (K/decade) Change (K/decade)

A mini resonance lidar workshop at CSU, August 2006

Group photo in front of Physics Department: in photo (from left to right) are Zhaoai YanGroup photo in front of Physics Department: in photo (from left to right) are Zhaoai Yan, Xinzhao Chu, Titus Yuan, Sandra Blindheim, Michael Gaussa, Phil Acott, Joe She, Sean Harrell, Wento Huang, Johannes Wiig, Paloma Farias, Dave Krueger, and Chihoko Yamashita. (Aug 06)

1

Atomic 56Fe energy level diagramz5 F o

3d6 4s4p 26874.549

27166.819

cm −1

cm −1

F55o

F54o

z 5Do D53o

126140 cm −1

372nm 374nm

D54o3d64s4p 25900 cm −1

5D 415 932 cm −1D5

386nm 389nm

a5D3d 6 4s2

0.000 cm −1

415.932 cmΔE ≅ 416cm − 1

D54

D3

Boltzmann lidar uses both transitions from 5D4 and 5D3; latter weak

Narrowband Fe lidars (@ 386 or 372 nm) uses the Doppler-broadenedNarrowband Fe lidars (@ 386 or 372 nm) uses the Doppler broadened transitions from the 5D4 level; these are pursued by IAP and CU groups

Recent trends in full-diurnal-cycle metal lidarsWhy Fe (UV) lidar and CW lidar for MLT studies?Lidar trans.λ (nm)

Group(Reference)

Transition Tuning/locking(Daytime filter)

Day Filter(divergence)

6 2 5Pulsed Fe(386)

IAP(Höffner et al., OL,2009)

(3d64s2‐5D4) –(3d64s4p‐5Do

4) Scan(Wavemeter)

Double-etalon(2 GHz)(50‐54 μrad)

Pulsed Fe(372)

CU (Chu et al., ILRC, 2008/2010)

(3d64s2‐5D4) –(3d64s4p‐5F o5) 

3 – freq(Doppler‐free and Optical heterodyne)

Double-etalon(under development)

heterodyne)

CW Na(589)

CSU/TMU/NIPR/CORA(Paper draft

D2 (3s2‐2S1/2) ‐(3s3p‐2P3/2)

3 – freq(Doppler‐free)

Faraday filter(2 GHz)(0.5 – 0.8 mrad)

/HAIPER Prop)

Multiple l(386, Fe)

TMU/NIPR(Abo/

Fe (3d64s2‐5D4) –(3d64s4p ‐

N2+ and Ca+ 

density onlyDouble etalonFaraday filter

(390‐1, N2+)

(393, Ca+)(770, K)

Nakamura) 5Do4) 

KD1 (3s2‐2S1/2) ‐(3s3p‐2P1/2)

Fe and K also temperatures

(under development)

Iron Lidar of IAP• Though with lower backscatter• Though with lower backscatter

coefficient, the high number density produces backscatter signal comparable to Na. The narrow

Left shows thesignal and backgroundnear September noon(Sep 25 07 13:15 UT) comparable to Na. The narrow

resonance line, operating at a field of view of 54 μrad yields an overall bandwidth of 2 GHz. This bandwidth

(Sep 25, 07_13:15 UT)before, between, andafter double etalons.Achievement of S/B ~ 

along with the low sky background and strong Fraunhofer line at 386 nm yields much reduced background in

10 is impressive.

observations under sunlit conditions as compared to current Na and K lidar.

• The center of the FOV is controlled to ithi 5 d d i d t kiwithin 5 μrad, a daring undertaking.

• The fundamental at 772 nm provides Rayleigh-Mie scattering information.

(Hoffner and Lautenbach, 2009)

The MRI Fe Lidar• The MRI iron lidar led by• The MRI iron lidar, led by

Xinzhao Chu, is under construction . The instrument and science potential wereand science potential were briefed in the 24th ILRC.

• Doppler-free with a 372-nm t l it di d lexternal cavity diode laser

(ECDL) and a hollow-cathode Fe discharge cell was also d d (24th ILRC)demonstrated (24th ILRC).

• The chirp (shift) of the pulses are monitored by optical y pheterodyne technique, pulse-to-pulse, the offset is removed by adjusting the seeder@ 744 nm j g @(Chu and Huang, 25th ILRC).

A mesopause region temperature/wind sodium lidar with pseudorandom modulation continuous-wave (PMCW) technique at 589 nm

Sh Ab Y N N kThe CSU Na lidar system in 2002 with two beams pointing 30o off zenith, to the east and to the north.

– She, Abo, Yue, Nagasawa, Nakamura

80

100

120

nter

val)

Night S/N Comparison

(a)

It is a small lidar with PA = 0.05 Wm2/beam. The uncertainties of CSU pulsed lidar at 1 h and 4 km resolution, between the minimum of 0.4 K (1.1 ) d / ( / ) h k k

20

40

60

80Pulsed_10.5UT

PMCW_10.5UT

Altit

ude

(4.0

km

in

K) and 1.5 m/s (2.1 m/s) at the Na peak, ~91 km to the lower edge of 1.2 K (7.7 K) and 2.1 m/s (12.4 m/s) at 80 km and to the upper edge of 3.0 K (31.3 K) and 4 8 m/s (117 m/s) at 105 km for night (local

0 100 200 300 400 5000

S/N (0.67min-4.0km)

A

winterK) and 4.8 m/s (117 m/s) at 105 km for night (local noon) condition, can be scaled to PMCW lidar. As shown, the ratio of the signal to noise ratio (S/N) of Pulsed/PMCW is conservatively estimated (with 80

100

120

terv

al)

Day S/N Comparison

(b)

winter

of Pulsed/PMCW is conservatively estimated (with the same reciever FOV) to be 3.7 (4.9). Thus to achieve comparable results with a PMCW lidarusing the same 35 cm diameter telescope, we  need  20

40

60

80

Pulsed_20.5UT

PMCW_20.5UT

Altit

ude

(4.0

km

in

g p ,a CW laser of 20 W power, still a compact system compared to an 1 W pulsed system. 0 20 40 60 80 100

0

20

S/N (0.67min-4.0km)

A

Targets for Multi‐wavelength Resonance Scattering Lidar for Syowa (69°S)Scattering Lidar for Syowa (69 S) (NIPR/TMU/Antarctic lidar group)

All based on two newly developed Alexandrite lasers

Courtesy of Abo/NakamuraFor Details, please visit PF ‐ 33

References• Höffner, Josef and Jens Lautenbach, Daylight measurements of mesopause

temperature and vertical wind with the mobile scanning iron lidar, Optics Letters, 34, 1351-1353 (2009).

• Chu X W Huang J S Friedman J P Thayer MRI: MOBILE FE• Chu, X., W. Huang, J. S. Friedman, J.P. Thayer, MRI: MOBILE FE-RESONANCE/RAYLEIGH/MIE DOPPLER LIDAR: PRINCIPLE, DESIGN, AND ANALYSIS, Proceeding ILRC24.

• S8P-02 Chu, X., W. Huang. FE DOPPLER-FREE SPECTROSCOPY ANDS8P 02 Chu, X., W. Huang. FE DOPPLER FREE SPECTROSCOPY AND OPTICAL HETERODYNE DETECTION FOR ACCURATE FREQUENCY CONTROL OF FE-RESONANCE DOPPLER LIDAR, Proceeding ILRC25, p. 969.

• She, C.-Y., M. Abo, J. Yue, C. Nagasawa and T. Nakamura, A mesopauseregion temperature/wind sodium lidar with pseudorandom modulation continuous-wave (PMCW) technique at 589 nm (in preparation)

• M Abo T Nakamura M Tsutsumi et al Development of Remote• M. Abo, T. Nakamura, M. Tsutsumi, et al., Development of Remote Controlled Lidar System and Multi-Wavelength Resonance Scattering Lidar System at Syowa Station, 27th Japanese Laser Sensing Symposium No PB-3 2009Sensing Symposium, No.PB 3, 2009.

Conclusion• Metal lidars of various type have proven to be effective for the• Metal lidars of various type have proven to be effective for the

study of mesosphere and lower thermosphere (MLT) science since 1985, about 25 years ago.Th CSU N lid i ll lid (35 di T l 1 W f• The CSU Na lidar is small lidar (35 cm dia. Telescope, 1 W for two beams), measuring T, U, V simultaneously with full-diurnal-cycle observation capability. Its potential for MLT science studies,

t th i ibl ith t lid h b f ll d t t dnot otherwise possible without a lidar has been fully demonstrated by dynamics studies with time scales ranging from 30 min to tens of years, for the study of gravity waves (GWs), tidal waves, l d T U V li l ll lplanetary wave and T, U, V climatology, as well as long-term

effects (volcanic response, solar cycle effect and temperature trends). Shorter period PWs possible with a larger lidar.

• Due to the desire to reduce the reception of sky background, Fe lidar at 386 and 272 nm are being developed. The desire for a compact lidar transmitter, the PMCW Na lidar, pioneered in p pJapan, is under investigation; it is potentially suitable for airborne and/or spaceborne observations.