mitsuteru sato - american astronautical society · 2014-07-21 · 3rd annual iss research and...

＃1 3rd Annual ISS Research and Development Conference, June 19, 2014

Mitsuteru SATO(1), T. Ushio(2),

T. Morimoto(3), H. Kikuchi(2), Y. Takahashi(1),

M. Mihara(1), Toru Adachi(4), M. Suzuki(5),

A. Yamazaki(5), U. Inan(6), and I. Linscott(6)

1. Hokkaido University, Japan

2. Osaka University, Japan

3. Kinki University, Japan

4. Meteorological Research Institute, Japan

5. ISAS / JAXA, Japan

6. Stanford University, Stanford, CA, USA


・JEM-GLIMS (Global Lightning and sprIte MeasurementS on JEM-EF)

・Lightning and TLEs observation from Japanese Experiment Module (JEM),

Exposed Facility (EF), ISS.

JEM-GLIMS

© NHK

Sprites

【 Objectives 】

1. Nadir observations of lightning and TLEs from ISS/JEM-EF,

2. Identification of sprite spatial distribution and generation mechanism,

3. Global survey of TLE occurrence.


Transient Luminous Events (TLEs) :

Lightning-excited transient discharge phenomena in the mesosphere

© NHK

Watch here!!

What is TLEs?


Sprite :

One of the occurrence type of TLEs.

© NHK

What is TLEs?

alt. (km)

90

80

70

60

50

• First discovered in 1989.

• Occurring in 50-90 km alt.

• Always excited by strong

cloud-to-ground lightning

discharges

• Most frequently observed.


• Occurrence types of TLEs.

What is TLEs?


Quasi-Electrostatic (QE) Field Model

The reason determining the horizontal distribution of sprites

is still big mystery since the discovery of sprites.

What is the Generation Mechanism?

[Pasko et al., 1997]

Most of the observational facts

can not be explained only by

the simple QE model.

We need more accurate

generation mechanism

of sprites.

Nadir observation is essentially effective.


What is the Occurrence Rates?

Global Occurrence Rates of Lightning

OTD / MicroLab-1 LIS / TRMM

We do not know the global occurrence rates and distributions of TLEs...

ISS is an ideal platform for the lightning and TLE observations.

ISS has 51° orbital inclination. Lighting and TLE observation by

scanning all the local time area!!


NOx production by sprites

Global occurrence rates and distributions of TLEs

Chemical Impact of Sprites on Earth’s Atmosphere

What is the Chemical Impact of TLEs?

We can evaluate chemical impact of TLEs on Earth’s atmosphere!!


Name ID Specification

CMOS Camera

(optical) LSI

Two CMOS cameras 512x512 pixels, FOV=28.3×28.3, fps = 29 (122, 488),

10 bit resolution,

LSI-1: = 762+/-5 nm, LSI-2: =765-830 nm

Photometer

(optical) PH

6 channel photometers = 150-280 nm, 316+/-5 nm, 337+/-5 nm, 392+/-5 nm,

= 762+/-5 nm, 600-900 nm

fs = 20 kHz, FOV=43, 12 bit resolution

VLF Receiver

(EM) VLFR

1 set of VLF antenna and a receiver f = 1-40 kHz, fs = 100 kHz, 16 bit resolution,

15cm monopole antenna

VHF

Interferometer

(EM) VITF

2 sets of VHF antennas and a receiver fs = 70-100 MHz, 8 bit, patch antenna, baseline=1.5 m

Science

instrument

Handling Unit SHU

Onboard computer Power control, Event triggering, Data acquisition & handling,

Command/telemetry I/F, Data compression

GLIMS Instruments


Item Value

Wavelength 765-830 nm (LSI-1)

762+/-5 nm (LSI-2)

FOV 28.3° × 28.3°

Optics F=1.4, f=25mm

Detector CMOS (STAR-250)

Pixel Number 512 × 512

Sensitivity 6.9E-6 W/m2

Resolution 10 bit

Spatial

Resolution

0.4 km/pix

@ ground surface

Time

Resolution

34.5 ms (29fps)

Table. Summary of LSI specification.

LSI

• ２ CMOS cameras (wide-band / narrow-band filter)

• LSI-1 : wide-band filter (lightning)

• LSI-2 : narrow-band filter (TLEs)

Fig. Picture of LSI flight model.

LSI-1

LSI-2

LSI (Lightning and Sprite Imager)


10

100

400

O2

ISS altitude

762nm

762nm

Alt. [km] Lightning Spectrum

Sprite Spectrum（N2 1PG）

LSI


Item Value

Wavelength 150-280 nm

337+/-5 nm

762+/-5 nm

600-900 nm

316+/-5 nm

392+/-5 nm

PH1

PH2

PH3

PH4

PH5

PH6

N2 LBH

N2 2P(0,0)

N2 1P(3,1)

N2 2P(0,0)

N2 2P(1,0)

N2+ 1N(0,0)

FOV 42.7°

86.8°

for PH1-3,5,6

for PH4

Detector PMT (R7400)

PDD (S1227)

for PH1-3,5,6

for PH4

Sensitivity @SNR=10

0.1E-6 W/m2

10E-6 W/m2

for PH1-3,5,6

for PH4

HV Range 0-1000 V

Resolution 12 bit

Sampling Freq. 20 kHz

Table. Summary of PH specification.

PH • 2 photometer units (PH-U)

• Absolute intensity measurement of

N2 1P, 2P, N2+ 1N emission lines

Fig. Picture of PH Unit #1 (top) and PH Unit #2 (bottom).


10

100

400

O3

ISS altitude

Alt. [km]

150-280nm

150-280nm

N2 LBH spectrum of sprites

Atmospheric transmittance

PH


Item Value

Freq. Range 1-30 kHz

Resolution 14 bit

Sampling Freq. 100 kHz

Antenna monopole antenna (15cm)

Table. Summary of VLFR specification.

VLFR

• VLF Receiver

• Detection of whistler wave generated by lightning

Fig. Picture of VLFR electronics (top) and VLFR antenna (bottom). Fig. Schematic illustration showing the propagation of whistler waves.


VITF

Item Value

Freq. Range 70-100 MHz

Resolution 8 bit

Sampling Freq. 200 MHz

Antenna patch-type antenna

Table. Summary of VITF specification.

• VHF Interferometer (VITF)

• Measurement of VHF pulses excited by lightning

Fig. Picture of VITF electronics (top) and VITF antennas (bottom). Fig. Development of lightning currents derived from VHF interferometer data.


GLIMS Instruments

PH-U1

PH-U2 LSI-1

VLFR antenna

Fig. Picture of GLIMS flight model.

SMA connectors for VITF antennas

LSI-2


IMAP/VISI REX-J

HDTV

SIMPLE

GLIMS/PH

IMAP/EUVI

GLIMS/LSI

GLIMS/VLFR-ANT

GLIMS/VITF-ANT

GLIMS/VITF-ANT Nadir

JEM-GLIMS and MCE Multi-mission Consolidated Equipment (MCE)


JEM-GLIMS was launched by H-IIB rocket and HTV-3 cargo ship 2012

Jul. 21

HTV-3 docked with ISS

Jul. 27

MCE was installed at JEM Exposed Facility (EF)

Aug. 9 GLIMS initial checkout operation started

Sep. 15 Initial checkout operation completed, and

started test observation

Nov. 12

Nominal operation started

Nov. 20 Continuous observation

and data acquisition 2013

Parameter studies for event triggering

Mission Status

2014


2013/03/22 22:10:47UT

10km

2012/12/25 12:49:04UT

10km

2013/01/01 19:36:17UT 2013/01/30 04:20:58UT

10km

2013/02/11 02:45:02UT

10km

2013/03/29 13:20:05UT

10km

2013/01/18 17:04:59UT

10km

2012/12/29 00:16:20UT

10km

10km

Period : 2012/ 11/ 20 - 2014/ 01/ 31

3,130 events

JEM-GLIMS Lightning Events


South Atlantic

Anomaly (SAA)

Period : 2012/ 11/ 20 - 2014/ 01/ 31

Global Map of Triggered Events

3,130 events


South Atlantic

Anomaly (SAA)

Seasonal Variation

Northern Summer (June, July, August)


Seasonal Variation

Northern Winter (December, January,

February)

South Atlantic

Anomaly (SAA)


20 km

LSI-1 LSI-2

765-830nm 762±5nm

Frame 1 (Ttrigg.=-33ms)

Frame 2 (Ttrigg. = 0ms)

Frame 3 (Ttrigg.=+33ms)


150-280nm

337nm

600-900nm

316nm

392nm

762nm

PH1

PH2

PH3

PH4

PH5

PH6

Trigger 2013/09/28 19:50:40.30580 UT @ Central Africa

Occurrence of TLEs

90 95 100 105 110 115 120 [ms]

Sprite Event / Outline of the Event




Subtracted Image LSI-1 Image

Existence of the

fine structures!!

20 km 20 km

Sprite Event / Image Subtraction


Sprite Event

2013/12/21 05:08:14.63340 UT @ Mexico, Middle America

Frame 3 (Ttrigg.= +33 ms)

Subtracted Image with LSI-1 Image LSI-1 Image

10 km 10 km

Subtracted image

Detailed horizontal structure of sprites is first identified!!


15 km

LSI-1 LSI-2

765-830nm 762±5nm

Frame 1 (Ttrigg.=-33ms)




150-280nm

337nm

600-900nm

316nm

392nm

762nm

PH1

PH2

PH3

PH4

PH5

PH6

Occurrence of TLEs

90 95 100 105 110 115 120 [ms]

2013/09/08 16:57:33.70315 UT @ Southern Australia

Elves Event / Outline of the Event


Elves Event / Interpretation

Due to the rapid lateral expansion (<1ms) and thin optical depth of the elves emission, LSI can not image elves (below the sensitivity).

Due to the wide FOV and high sensitivity, PH can only detect elves signal.

FOV of LSI (160km×160km @90km)

iFOV of LSI (0.3km×0.3km @90km)

FOV of PH (42.7° conical)

Elves

Propagation of EMP

Alt.

[km]

410

90

10

GLIMS

Lateral expansion

CG discharge

(r=125km circle @90km)


Lightning Whistler

2013/09/09 13:04:07.39706 UT

Lightning emission

Lightning whistler

Time delay from the lightning

can be reasonably explained by

the propagation of whistler

wave with a group velocity (Vg).

Frequency Dispersion

Electrical properties of

lightning discharge.


VHF Pulses

2013/05/25 14:50:30.18751 UT Lightning images (LSI)

Light curve data of PH

VHF pulses are mainly emitted by

in-cloud lightning currents.

Detection number of VHF

pulses

Sample waveforms of VHF

pulses

First identification!!

We will estimate source location

using interferometric technique.


JEM-GLIMS is continuing nadir observations of lightning &

TLEs from ISS, and it succeeded in detecting thousands of

lighting events since Nov. 2012.

JEM-GLIMS succeeded in detecting sprite and elves events by

the optical instruments.

JEM-GLIMS also succeeded in detecting lighting whistler and

VHF pulses, which enable us to identify the electrical

properties of lightning discharges.

Future Plan

Comparison between GLIMS optical data and GLIMS/VLF and VHF

data to clarify the generation mechanism of sprites,

Identification of seasonal / LT dependences of TLE occurrences.

Conclusion


Appendix


Global Map of FUV Events

South Atlantic

Anomaly (SAA)

Period : 2012/ 11/ 20 - 2014/ 01/ 31

PH1 Events = 365

Global Distribution of Possible TLEs


JEM-GLIMS and MCE

PH Unit1

LSI

PH Unit2

VLF

Antenna

VITF

Antenna #1

GLIMS Main

Instruments

MCE VITF

Antenna #2

©JAXA

GLIMS

• 2-channel CMOS cameras (LSI)

• 6-channel photometers (PH)

• VLF receiver (VLFR)

• 2-sets of VHF receivers (VITF)


Item Value

Main Function Power control Data acquisition Event trigger Data compression (HIREW encoding) GPS time synchronization Command, Telemetry I/F (RS422 I/F)

FPGA Xilinx Vertex II

CPU SH2

S-RAM 8MB x 2 for FPGA (temporal data buffering)

8MB for CPU

Mass Memory 128MB (FIFO memory for TLM)

Table. Summary of SHU specification.

SHU SHU (Science instruments Handling Unit)

• Power control (power, A/D)

• Event trigger, data acquisition

• GPS synchronization

• data compression： HIREW (lossless)

• Command and telemetry interface

Fig. Picture of SHU flight model.


LSI-1

Image


x (1/α)

ave+5σ

LSI-2

Image

Sprite Event / Image Subtraction


Peak intensities of PH light curve data

PH1 (150-280nm)

PH2 (337nm)

PH3 (762nm)

PH4 (600-900nm)

PH5 (316nm)

PH6 (392nm)

98 99 100 101 102 103 104 [ms]

Peak Intensities

150-280nm:

2.02×10-7 [W/m2]

337nm: 2.52×10-4 [W/m2]

762nm: 1.46×10-4 [W/m2]

600-900nm:

1.01×10-2 [W/m2]

316nm: 3.29×10-5 [W/m2]

392nm: 2.88×10-4 [W/m2]

Sprite Event / Absolute Intensity of PH Data


Log（Ratio）

337nm / Red(610-750nm) 337nm / Red(600-900nm)

Ratio (337 / Red) Occurrence probability of TLEs

0.68 10 %

1.07 20 %

2.09 40 %

4.47 60 %

11.7 80 %

Sprite Event / Intensity Ratio, Occurrence Probability O

ccu

rre

nce

Pro

ba

bili

ty

Log（Ratio）

Occu

rre

nce

Pro

ba

bili

ty

ISUAL Case GLIMS Lightning Case

[ Adachi et al., AE33A-0317, this meeting ]


(337/Red): x 26

100 200 300 400 500 600 700 800 900

Wavelength [nm]

102

101

100

10-1

10-2

10-3

10-4

10-5

Re

lati

ve I

nte

nsit

y R

ati

o

Relative Intensity Ratio toward PH4(600-900nm) Intensity

GLIMS Lightning Event

Analyzed Event

Sprite Event / Intensity Ratio

( 337 / Red ) = x 26 ( 392 / Red ) = x 25

Occurrence Probability of TLEs

80% at (337/Red)=11.7

[ Adachi et al., AE33A-0317, this meeting ]


GLIMS

data

ELF

data

40.0 40.2 40.4 40.6 40.8 41.0 [sec]

PH2

NS-comp

EW-comp

NS-comp

EW-comp

Δt = 35.6 ms

(8.5 Mm @ v=0.8c)

Δt = 43.0 ms

(10.4 Mm @ v=0.8c)

Sprite Event / Electrical Properties of Parent CG

Esrange (Kiruna)

Syowa (Antarctica)

40

0

-40 40

0

-40

20

0

-20 20

0

-20

0.0 0.1 0.2 0.3 0.4 0.5 [sec]

4.0

2.0

0.0

[ V

]

[ pT

]

[ pT

]

Possible CG Time = 40.30443 [sec]

↓ Trigger time = 40.30580 [sec]



Propagation Paths of the ELF Waves

Distance between sub-satellite point (SSP) and ELF stations

SSP – Esrange = 7.0 Mm

SSP - Syowa = 8.5 Mm

(13.695°E, 5.540°N)

Location of the sub-satellite point (SSP)

Actual distances between SSP and ELF stations are comparable to these derived from propagation time of the ELF waves.

Cross point of the two great circles and sub-satellite point are very close.

Propagation Path @ESR

Propagation Path @Syowa

Esrange

Sub-satellite point (13.695°E, 5.540°N)

Syowa

8.5 Mm

7.0 Mm

Cross point of the two great circles


Current Moment Waveform (ESR data)

HΦ(f) : observed magnetic filed spectrum Idl(f) : current moment spectrum I0dl : peak current moment θ : angular distance RE : radius of the Earth h0 : wave reflection height n : mode number ν : propagation coefficient Pm : Legendre polynomial τ : time constant of the lightning current

Charge Moment Change (CMC) Estimation

Current Moment Spectrum


Station CMC

Esrange +1843 [Ckm]

Syowa +1622 [Ckm]

Assumed Current Moment Waveform

Enough to excite sprites!!

Current Moment Spectrum (ESR data)

CMC = +1843 [Ckm]


Field-of-view (FOV) of LSI and PH

FOV of LSI and PH

FOV of PH1-3, PH5, PH6(42.7

o, conical)

FOV of LSI(28.7

o x 28.7

o, square)

FOV of PH4(86.8

o, conical)

210 km

210 km

378 km

156 km


• PH1 signals are originated from N2 Lyman-Birge-Hopfield (LBH) emission.

• Sprites can emit N2 LBH emission [Gordillo‐Vázquez et al., 2011; Kuo et al., 2007;

Chang et al., 2010].

• Lightning FUV emission may not reach ISS altitude due to the severe O3

absorption. It this event related to TLEs???

Fig. Simulated N2 LBH spectrum of sprite halo

[Gordillo‐Vázquez et al., 2011].

N2 LBH Spectrum of Sprite Halo

Fig. Calculated atmospheric transmittance in the visible range.

FUV Emission and Atmos. Transmittance

mitsuteru sato - american astronautical society · 2014-07-21 · 3rd annual iss research and...

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