Calibration and instrument status of ADEOS-II Global Imager

September 8,2003SPIE Remote Sensing 2003

GLI Calibration TeamS. Kuriharaa, H. Murakamib, K. Tanakaa, H. Hashimotob, I. Asanumab, J. Inouec

a NASDA ADEOS-II Project,b NASDA EORC

c NASDA EOC

GLI : Global Imager

• Multi spectral optical imager with wide FOV on ADEOS-II• Global observation succeeding OCTS on ADEOS platform.

+X

+Y+Z

Sea Winds

AMSR

ILAS-II

POLDER

GLI

Specification

1.25 mrad (1km resolution, 30ch)

0.3125 mrad (250m resolution, 6ch)

Instantaneous Field Of View (IFOV)

-20deg, 0deg, +20degTilt Angle

+/- 45 deg

（1600km cross track swath）

Field Of View (FOV)

4dayRepeat period

3.3～12 micron （total 7 channels）Middle Thermal infrared channels (MTIR)

1.1～2.2 micron （total 6 channels）Short Wave infrared channels (SWIR)

380～865 nm （total 23 channels）Visible Near infrared channels (VNIR)

GLI on-orbit initial checkout

▲Safety Mode

CAL/VALphase

Milestone ▲

Launch Dec 14

(～ Jan 10)

２００３

AprMar

２００２

Dec Jan Feb

check out phase

Critical phase

Jun

Apr 14▽

GLICheckout Jan 10▲

Cool Down

#1 C/O

Jan 24-26

#2 C/O

2/6-7

2/12,15,22,25▲ △ ▲ △A B A B

Lamp Calibration

3/7▲Lamp Calibrationvia DRTS

System Total Test

Initial critical phase (to Dec 17）

May Jul Aug Sep Oct Nov Dec

Operationalphase

▲Today

CAL/VAL activity

GLI first ImageJan. 25 2003

Instruments Status (1/2)

-25℃

-20℃

-15℃

-10℃

-5℃

0℃

5℃

10℃

15℃

20℃

25℃

30℃

DIS

P TE

MP

PELT

IER

RA

DTE

MP

OTC

TEM

P

SCA

N M

TR T

EMP

SCA

N E

NC

TEM

P

TILT

MTR

TEM

P

BB

C T

EMP

45 M

IRR

OR

TEM

P

LAM

P TE

MP1

LAM

P TE

MP2

LEN

S TE

MP1

(MT-

Lens

)

LEN

S TE

MP6

(VN

2-Le

ns)

VN

-DET

1 TE

MP

VN

-DET

2 TE

MP

SW-D

ET1

TEM

P

ASP

TEM

P2

MT-

PRE

TEM

P3

Max (On orbit). Min. (On orbit) Analysis Cold Analysis Hot

• ALL GLI commands is successfully executed through all initial checkout activities and routine operation.

• All GLI temperature and currents are equivalent to the pre-launch testing and/or predictions within allowable limits with proper margin.

GLI component temperatures during 19-22 March (System total test).

Instruments Status (2/2)

-5

0

5

10

11-Jan

18-Jan

25-Jan

1-Feb

8-Feb

15-Feb

22-Feb

1-M

ar

8-M

ar

15-M

ar

22-M

ar

29-M

ar

5-A

pr

12-A

pr

19-A

pr

26-A

pr

3-M

ay

10-M

ay

17-M

ay

24-M

ay

31-M

ay

7-Jun

14-Jun

21-Jun

28-Jun

5-Jul

GL4151 SCAN ENC TEMP (Max.)　 GL4151 SCAN ENC TEMP (Min.)　

GLI’s temperature is stable in routine operation.

Example of GLI’s telemetry: Scan encoder temperature

VN/SW Band

• Dynamic Range and Linearity– Equivalent to pre-launch ground test data

• Non-Linearity, Over-saturation– Equivalent to pre-launch ground test data – data is “tailing” in non-linear region– required for the detailed analysis for non-linear region response.– detailed analysis is on-going as a Cal/Val phase activity

• Strip pattern noise– Mirror side difference is stronger than detector response deviation for data

striping– detailed analysis is on-going as a Cal/Val phase activity

• Long term sensitivity– detector sensitivity is stable according to on board calibration data

Over saturation & tailing

Over saturation

GLI

DN

Radiance

GLI

DN

Input radiance

Tailing

GLI

DN

RadianceScanning Direction Linear Max

Over saturation Tailing Over saturation+Tailing

Non-linear region

• Over saturation: DN decreased when input radiance increased in non-linear region at VNIR2 band•Tailing: Increasing input DN when detector is continued to input radiance of saturation region

0

500

1000

1500

2000

2500

3000

3750 3800 3850 3900 3950 4000 4050 4100 4150

ch18出力 （深宇宙補正前） [DN]

ch19出

力 （

深宇

宙補

正前

） [D

N]

Over saturation

Over saturation & tailing (Example)

Ch18 (High gain) Cf. Ch19 (Low gain)

tailing

Over saturation

These phenomena is found in only non-liner region.

Same wavelength (866nm)

Noise (Strip pattern)

• 1) Detector sensitivity error• 2) Mirror side difference error• 3) Electric error (MT band only)

Strip pattern noise appears in GLI image.

Error 2) is greater than Error 1)

Detector sensitivity error

0.96

0.98

1

1.02

1.04

1.06

1.08

Det1 Det2 Det3 Det4 Det5 Det6 Det7 Det8 Det9Det1

0Det1

1Det1

2

Detector

Ratio

to d

et. 7

ch10 Solar cal ch10 Earth observationch10 Ground test

The detector sensitivity error differs from the error by earth observation and by solar calibration about 1 or 2%.

Mirror side difference error

Mirror side B/ Mirror side A

0.95

0.96

0.97

0.98

0.99

1

1.01

1.02

1.03

1.04

0 50 100 150 200

Day from launch

Ratio

to 1

2/14

/200

2ch2(400nm)

ch6(490nm)ch10(625nm)

ch15(710nm)

ch19(865nm)ch26(1240nm)

Ground test data

Mirror side difference error on orbit differs from it on pre-launch test data.

Lamp data

Correction of strip pattern noise

GLI L1B data will be carried out de-striping

Original L1B image De-striping L1B image

Strip noise (problem)

• Strip pattern correction is not perfect because of mirror side difference• Stray light may cause change of mirror side difference

Observation image in CH18 when moon light incidented through deep

space window

The mirror side A (Red) is about two times bigger than it of mirror

side B (Blue).

Long term sensitivity (Solar Calibration)

• The change ratio at mirror side A on CH 2 (400nm) and CH 26 (1240nm) decrees about 10% and 2% respectively for 140 days

• The shorter wavelength is faster degradation than longer wavelength.• The change ratio at mirror side B is bigger than it at mirror side A

Sun Calibration trend (Sun EL 15 deg mirror side A)

0.88

0.9

0.92

0.94

0.96

0.98

1

1.02

0 50 100 150 200

Day from launch

Ratio

to 1

/26/

2003

ch2

ch6

ch10

ch15

ch19

ch26

Sun Calibration trend (Sun EL 15 deg mirror side B)

0.88

0.9

0.92

0.94

0.96

0.98

1

1.02

0 50 100 150 200

Day from launchRa

tio to

1/2

6/20

03

ch2

ch6

ch10

ch15

ch19

ch26

Long term sensitivity (Lamp calibration)

• The DN of lamp in orbit is different from ground test data.• Data of mirror side A is increasing, but data of mirror side B is

decreasing

Internal Lamp A mirror side A

0.94

0.96

0.98

1

1.02

1.04

1.06

1.08

0 50 100 150 200

Day from launch

Ratio

to g

roun

d te

st da

ta

ch2(400nm)

ch6(490nm)

ch10(625nm)

ch15(710nm)

ch19(865nm)

ch26(1240nm)

Internal Lamp A mirror side B

0.96

0.98

1

1.02

1.04

1.06

1.08

0 50 100 150 200

Day from launch

Ratio

to G

roun

d te

st da

tach2(400nm)ch6(490nm)ch10(625nm)ch15(710nm)ch19(865nm)ch26(1240nm)

Ground test data

•Lamp data remain stable on orbit•Solar data decrease(Degradation of diffuser ? No degradation of GLI output ?)

We consider GLI is stable by on board calibration data(Vicarious calibration data show other results ? )

We continue to more detail study this topic.

Long term sensitivity (Summary)

Lamp rate - Sun rate

-0.14

-0.12

-0.1

-0.08

-0.06

-0.04

-0.02

0

300 500 700 900 1100 1300

Wave Length (nm)

Rate

of c

hang

e fr

om 1

/26/

2003

to15

/6/2

003

Lamp A Mirror side A

Lamp A Mirror side B

Lamp B Mirror side A

Lamp B Mirror side B

Degradation

0.86

0.88

0.9

0.92

0.94

0.96

0.98

1

1.02

1.04

300 500 700 900 1100 1300 1500

Wave Length (nm)

Rat

e o

f chan

ge f

rom

1/26/2003 t

o15/6/2003

Lamp mirror sideA

Lamp mirror sideB

Solar mirrror side A

Solar mirror side B

Vicarious calibration result (long term trend)

Temporal change Vicarious calibration by SeaWiFS and simulation(SPIE, San Diego 2003,5155-10 H.Murakami)

Ch1 Degradation?

Cross calibration over snow fields near Barrow, Alaska(SPIE, San Diego 2003,

5151-46, Nieke)

Degradation?

MT band

• Detector Response– Equivalent to pre-launch ground test data– detailed analysis is on-going as a Cal/Val phase activity

• Strip pattern noise– Strip noise in MT band is smaller than it in VN/SW band – Electric noise appear

• Black Body Calibration– Black Body Calibration function is confirmed– 2 points calibration method (deep space & black body) functions properly.– Calibration coefficients are stable

Electric noise

•Detector and mirror side noise can be corrected, but electrical noise remain after the current de-striping process on MT band.

Original image De-striping image

MT calibration coefficients trend

Ch36 C1' trend Det1 Mirror side A Scene 1

99.60%

99.80%

100.00%

100.20%

100.40%

100.60%

100.80%

Jan

-03

Feb-

03

Feb-

03

Mar

-03

Apr

-03

Apr

-03

May

-03

Jun-03

Jun-03

Jul-

03

Aug-

03

Rat

io t

o 2

5 J

an. 2003

Initial check out

•The calibration coefficients are stable. •The change is within 0.2% at ch 36 in a day.

CH C1' 30 3.5% 31 0.5% 32 0.4% 33 0.3% 34 0.2% 35 0.2% 36 0.2%

Change of coefficient in a day

- 1 0

- 5

0

11-Jan

18-Jan

25-Jan

1-Feb

8-Feb

15-Feb

22-Feb

1-M

ar

8-M

ar

15-M

ar

22-M

ar

29-M

ar

5-A

pr

12-A

pr

19-A

pr

26-A

pr

3-M

ay

10-M

ay

17-M

ay

24-M

ay

31-M

ay

7-Jun

14-Jun

21-Jun

28-Jun

5-Jul

G L 4 1 3 1 B B C T E M P ( M a x .) G L 4 1 3 1 B B C T E M P ( M in .)

Geometric status

Refer to Con. 5234A-07 (today 11:10AM)

Pre launch test parameter Updated parameter

The geo location errors are about 2 samples using pre launch alignment data.

We will update alignments parameter in the next L1 software version.

Summary

• All GLI components status are normal within the predicted ranges. • Output level and calibration coefficients is stable.• Several sensor characteristics analysis is on-going for the CAL/VAL

phase activity, such as;– Non-Linearity Response– Mirror side difference and destriping– sensor degradation– Vicarious calibration– others

• The target for these analysis is GLI data delivery to the public at the end of this year