progress of in-flight calibration of hj-1a/hsi

21
Progress of in-flight Calibration of HJ-1A/HSI Li Chuanrong Invited expert of NRSCC Professor and Vice President Academy of Opto-Electronics,CAS Phuket, Nov 03, 2009 1 23 rd CEOS Plenary I Phuket, Thailand I 3-5 December 2009

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Progress of in-flight Calibration of HJ-1A/HSI. Li Chuanrong Invited expert of NRSCC Professor and Vice President Academy of Opto-Electronics,CAS Phuket, Nov 03, 2009. Contents. Brief introduction of HJ satellite and HSI senor CAL/VAL activities of HJ-1A/HSI Challenges Prospect. - PowerPoint PPT Presentation

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Progress of in-flight Calibration of HJ-1A/HSI

Li Chuanrong Invited expert of NRSCC

Professor and Vice President Academy of Opto-Electronics,CAS

Phuket, Nov 03, 2009

123rd CEOS Plenary I Phuket, Thailand I 3-5 December 2009

Contents

Brief introduction of HJ satellite and HSI senorCAL/VAL activities of HJ-1A/HSIChallenges Prospect

23rd CEOS Plenary I Phuket, Thailand I 3-5 December 2009 2

Introduction

23rd CEOS Plenary I Phuket, Thailand I 3-5 December 2009 3

““ 2+1”2+1”““ 2+1”2+1”22 optical optical moonletmoonletss22 optical optical moonletmoonletss

11 radarradar--moonletmoonlet11 radarradar--moonletmoonlet

first-stagefirst-stage

““4+4” 4+4” ““4+4” 4+4”

4 4 optical optical satellitesatellitess4 4 optical optical satellitesatellitess

44 radarradar satellite satellitess44 radarradar satellite satellitess

second-stagesecond-stage

• On 2008.09.06, the small satellite constellation HJ -1A/1B were launched by a single LM-2C (CZ-2C) launch vehicle.

• On 2009.03.30, HJ -1A/1B were ready for operational applications.• HJ -1C will launch soon.

Introduction

23rd CEOS Plenary I Phuket, Thailand I 3-5 December 2009 4

satellitesatellite HJ-1AHJ-1A HJ-1BHJ-1B

payloadpayload2 2 CCDs CCDs 2 2 CCDs CCDs

HSIHSI IRSIRS

orbital type sun-synchronous orbitorbital height ( km) 649.093orbital inclination 97.9486orbital period (minute) 97.5600circles per day 14+23/31revisiting period (hour)

CCD 96 (48 with HJ-1A/1B combination)HSI 96IRS 96coverage period (day) 31coverage period circles 457local time at descending node 10:30 AM ± 30min

The small satellite for environment and disaster ( HJ-1A) in China carried a hyper-Spectral Imaging (HSI) sensor, designed by Academy of Sciences, CAS

HJ-1A

Spectral range: 450nm-950nmBand number: 115 Spatial resolution: 100mSwath: 50kmSide-looking: ±30°Revisiting: 4-31days

Introduction

Principles of HSI

23rd CEOS Plenary I Phuket, Thailand I 3-5 December 2009 6

On-orbit calibration

lamp

Integral sphere

Collimation lens

Ground object

Switch mirror

Object lens Slit

Sagnac prism

Fourier lens

Cylindrical lens

Detector

The imaging approach used by HSI is a spatially modulated Fourier transform method based on a Sagnac interferometer.

Onboard inner calibration mode and earth observation mode can be switched by a swing mirror.

Introduction

23rd CEOS Plenary I Phuket, Thailand I 3-5 December 2009 7

Principles of HSIIntroduction

HSIImaging

SpectrumRebuild (base

on IFFT)

PushSweep

GroundObject(line)

Interferogram

Interferogramquence

SpectrumCube (115

bands)

Swath Width

Swath Width512

OPD256

115 band

nn

512

Imaging Parameters of HSI

ParametersHJ-1A EO-1

CCD HSI ALI Hyperion

Spectral Range 430-900nm 450-950nm 400-2400nm 400-2500nm

Spatial Resolution 30m 100m 30m 30m

Swath Width 360km 50km 36km 7.5km

Spectral Resolution -- ~4.3nm -- ~10nm

Number of Bands 4 115 10 220

Comparison of Parameters Between HJ-1A and EO-1

Introduction

823rd CEOS Plenary I Phuket, Thailand I 3-5 December 2009

• Calibration requirement to HSI: New imaging system and mechanism—We have

less experiences We have not carried out on board calibration

with consideration of instrument safetyWith the issues above we do need more sites and

more experiments to study the way to calibrate this new kind of sensor

CAL/VAL activities of HJ-1A/HSI

23rd CEOS Plenary I Phuket, Thailand I 3-5 December 2009 9

Vicarious calibration activities

• Dunhuang Site (twice after launch)– 40.08N, 94. 38E– Altitude: 1200m– 2008.10.14-2008.10.22 (Gain level 1)– 2009.08.19-2009.08.29 (Gain level 2)

• Inner Mongolia (once for validation)– 2009.09

23rd CEOS Plenary I Phuket, Thailand I 3-5 December 2009 10

CAL/VAL activities of HJ-1A/HSI

Measure Target

Surface Properties

MeasureAtmospheric

Properties

Radiative Transfer Model- Modtran; 6S

Predicted At-Sensor Radiance (L)

Illumination+ Viewing

angles Sensor Signal (DN)

DN

LGain=dL/dDN

offset

Sensor’s spectral

response function

Vicarious calibration at Dunhuang Site

23rd CEOS Plenary I Phuket, Thailand I 3-5 December 2009 11

Radiometric vicarious calibration results of HSI ( Gain1)WL(nm) Gain WL(nm) Gain WL(nm) Gain WL(nm) Gain WL(nm) Gain

460.04 0.2927 513.56 1.0333 581.18 1.7071 669.29 2.9618 788.89 4.4275

462.14 0.3050 516.17 1.1463 584.52 1.7016 673.73 3.0574 795.07 4.6644

464.25 0.3447 518.81 1.1874 587.90 1.7869 678.23 3.0978 801.34 4.6438

466.38 0.3786 521.48 1.1288 591.33 1.9722 682.79 3.1684 807.72 4.5858

468.53 0.4018 524.17 1.1658 594.79 2.0156 687.41 3.4454 814.20 4.9406

470.71 0.4296 526.89 1.2008 598.30 1.9759 692.10 4.3658 820.78 6.4526

472.90 0.4713 529.64 1.2321 601.85 1.9553 696.85 3.9148 827.47 5.5252

475.11 0.5059 532.42 1.2460 605.44 1.9843 701.66 3.8392 834.27 5.3826

477.35 0.5022 535.22 1.3309 609.07 2.0150 706.54 3.8968 841.18 4.5829

479.60 0.5239 538.06 1.2698 612.74 2.1141 711.50 3.7569 848.20 4.3767

481.88 0.6020 540.92 1.4228 616.46 2.2630 716.52 3.7909 855.35 4.4874

484.18 0.6329 543.82 1.3548 620.23 2.1945 721.61 5.8620 862.62 4.2436

486.50 0.7557 546.75 1.3759 624.04 2.1912 726.77 5.1258 870.01 4.3057

488.84 0.7367 549.71 1.4898 627.90 2.3906 732.01 5.5057 877.53 4.1998

491.20 0.7456 552.70 1.4741 631.81 2.4263 737.33 4.3242 885.18 4.1541

493.59 0.8194 555.73 1.4915 635.76 2.4634 742.73 4.1700 892.96 4.0919

496.00 0.7721 558.79 1.5827 639.77 2.4562 748.20 3.9960 900.89 5.7221

498.44 0.8276 561.88 1.5462 643.82 2.5488 753.75 3.9403 908.95 5.6478

500.90 0.8993 565.00 1.5896 647.93 2.7137 759.39 3.8426 917.16 6.2722

503.38 0.9542 568.16 1.6073 652.09 2.9064 765.11 11.5210 925.52 4.7639

505.89 0.9832 571.36 1.6783 656.31 2.9426 770.92 4.5856 934.04 7.7071

508.42 1.0366 574.60 1.5987 660.58 2.9840 776.82 4.0644 942.71 12.8335

510.98 1.0400 577.87 1.6443 664.90 2.8501 782.81 4.1707 951.54 10.0017 12

Cross comparison at Dunhuang site

Between HJ-1A/HSI channels and corresponding MODIS bands

HSI Radiance

Cross comparision

Spectralconvolution

MODIS Radiance

HSI Convolved Radiance

Si te Registration

23rd CEOS Plenary I Phuket, Thailand I 3-5 December 2009 13

HJ-1A/HSI and Terra/MODIS Image Pairs

MODIS channel 1

UTM 04:25 May 29,2009

HSI channel 73

UTM 04:41, May 29,2009870

pixels

180 pixels

Cross-comparison at Dunhuang site

23rd CEOS Plenary I Phuket, Thailand I 3-5 December 2009 14

CAL/VAL activities of HJ-1A/HSI

Spectral response of MODI S

0. 00

0. 20

0. 40

0. 60

0. 80

1. 00

400 500 600 700 800 900 1000

wavel ength nm( )

SRF/

Ref

HSI spectralcoverageMODI S channel 1

MODI S channel 2

MODI S channel 3

MODI S channel 4

MODIS channel 1 HSI channels 57-74

MODIS channel 2 HSI channels 98-109

MODIS channel 3 HSI channels 1-11

MODIS channel 4 HSI channels 34-43

23rd CEOS Plenary I Phuket, Thailand I 3-5 December 2009 15

Cross-comparison at Dunhuang site

CAL/VAL activities of HJ-1A/HSI

MODIS observed radiance HSI-convolved radiance

MODIS channel 1 112.6021 109.5861

MODIS channel 2 74.00458 65.9016

MODIS channel 3 126.2463 135.7682

MODIS channel 4 120.6291 123.0256

distinction of observing geometry and atmosphere due to different acquisition time

Discrepancy

MODIS calibration accuracy

HSI calibration accuracy

1 2 3

16

Cross-comparison at Dunhuang site

CAL/VAL activities of HJ-1A/HSI

Current challenges

Uncertainties in radiometric vicarious calibration

Radiometric cross-calibration method based on other well-calibrated satellite data is to be studied

Spectral calibration is to be expected

23rd CEOS Plenary I Phuket, Thailand I 3-5 December 2009 17

Prospect Invited by former WGCV group chair Dr. Cao Changyong, we will

take part in Antarctic Dome C project on behalf of NRSCC The actions including confirmation of coverage area of Antarctic

region and planning of data acquisition in Dec. of this year has been carried out

By working on this project, AOE, as technical and operational facilitator of NRSCC, is willing to join the actions of CEOS WGCV.

AOE will also be pleasant to technically bridge the action cooperation between CEOS and China related agencies, such as data democracy, calibration, validation, virtual constellation etc.

23rd CEOS Plenary I Phuket, Thailand I 3-5 December 2009 18

Anticipated agency participation HJ-1A/HSI image over Dome C area for example

23rd CEOS Plenary I Phuket, Thailand I 3-5 December 2009 19

2009-09-13 23:59

scene Center Latitude: S74.676132°

scene Center Longitude:E124.513398°

solar altitude angle: 5.5°

Anticipated agency participation Near-term plans

Provide related HJ-1A/HSI data and technical parameters support, so as to enrich datasets about the Dome C site.

In accordance with the procedure of CEOS/WGCV, carry out the cross-calibration studies between HJ-1A/HSI and other well-calibrated visible/near infrared sensors based on the Antarctic Dome C calibration site.

Invite foreign calibration experts including those work for CEOS to go to China for scientific discussion periodically.

23rd CEOS Plenary I Phuket, Thailand I 3-5 December 2009 20

Thank you !Thank you !