9881-26 Proto Flight Model (PFM) development status of Visible...
Transcript of 9881-26 Proto Flight Model (PFM) development status of Visible...
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Proto Flight Model (PFM) development statusof Visible and Near-Infrared Radiometer (VNR)
on the Second-Generation Global Imager (SGLI)
6 April 2016
T. Sakashita, S. Tsuida, T. Amano, K. Shiratama (NEC)Kazuhiro Tanaka (JAXA)
9881-26
10th SPIE Asia-Pacific Remote Sensing SymposiumEarth Observing Missions and Sensors: Development, Implementation, and Characterization IV
New Delhi, India, 4-7 April 2016
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Contents
GCOM mission and satellite SGLI specification (SGLI-VNR and SGLI-IRS) SGLI VNR Current Status Test Results of VNR VNR Geometric Test VNR Radiometric Test NP Polarization Sensitivity PL Polarization Measurement
Conclusion
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Global Change Observation Mission (GCOM)
Global observation satellite system as JAXA’s GEOSS contribution. 2 satellite series for 5 years, total 13 years observation. GCOM-W Microwave radiometer observation for WATER
CYCLE using AMSR2 (AMSR-E follow on) GCOM-C Optical multi-channel observation for
RADIATION BUDGET and CARBON CYCLE using SGLI(GLI follow on)
GCOM-Cis scheduled forlaunch in 2017.
GCOM-C(CLIMATE)
SensorAdvanced Microwave Radiometer 2 (AMSR2)
Passive Microwave ObservationWater vapor, soil moisture etc
SensorSecond Generation Global Imager(SGLI)
Optical Observation 380nm – 12 micronCloud, Aerosol, Vegetation, Chrolophl etc
GCOM-W(WATER) AMSR2
SGLIGCOM-W “SHIZUKU” was launched on May 18, 2012.
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SGLI on GCOM-C1 satellite
SGLI Second Generation Global ImagerVNR Visible and Near Infrared RadiometerIRS Infrared Scanning RadiometerSRU Scanning Radiometer UnitELU Electronic Unit
Mission Life > 5 years
Solar Paddle > 4000w (End of Life)
Mass about 2,000kg
SGLI IRSELU
+X
flight direction+Y
+Z earth
deepspace
SGLI VNRELU
SGLI IRSSRU
SGLI VNRSRU
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SGLI (Second Generation Global Imager)
PolarizedObservationTelescopes(55deg FOVx 2)
Non PolarizedObservation Telescopes(24deg FOV x 3)
SolarDiffuser
About1.7m
About1.3m
Infrared Scanning Radiometer(SGLI-IRS)
EarthView Window
DeepSpaceWindow
About1.4m
About0.6m
Sensor Unit Features
SGLI VNRNon Polarized Observation (11ch), IFOV 250m, Swath 1150kmPolarized Observation(2ch), IFOV 1km, Swath 1150km
SGLI IRSShortwave Infrared (SWI 4ch), IFOV 250m/1km, Swath 1400kmThermal Infrared (TIR:2ch), IFOV 500m, Swath 1400km
Visible and Near Infrared Radiometer(SGLI-VNR)
Sun Cal.Window
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SGLI Specification
SGLI channels
CH
Lstd Lmax SNR at Lstd IFOV
VN, P, SW: nmT: m
VN, P: W/m2/sr/m
T: Kelvin
VN, P, SW: SNR
T: NETm
VN1 380 10 60 210 250 250VN2 412 10 75 250 400 250VN3 443 10 64 400 300 250VN4 490 10 53 120 400 250VN5 530 20 41 350 250 250VN6 565 20 33 90 400 250VN7 673.5 20 23 62 400 250VN8 673.5 20 25 210 250 250VN9 763 12 40 350 1200 250/1000VN10 868.5 20 8 30 400 250VN11 868.5 20 30 300 200 250P1 673.5 20 25 250 250 1000P2 868.5 20 30 300 250 1000
SW1 1050 20 57 248 500 1000SW2 1380 20 8 103 150 1000SW3 1630 200 3 50 57 250SW4 2210 50 1.9 20 211 1000T1 10.8 0.7 300 340 0.2 250/500T2 12.0 0.7 300 340 0.2 250/500
•The SGLI features are 250m (VNR-NP & SW3) and 500m (TIR)spatial resolution and polarization/along-track slant viewchannels (VNR-PL), which will improve land, coastal, and aerosol observations.
GCOM-C SGLI characteristics
OrbitSun-synchronous(descending local time: 10:30)Altitude 798km, Inclination 98.6deg
Mission Life 5 years (3 satellites; total 13 years)
Scan Push-broom electric scan (VNR)Wisk-broom mechanical scan (IRS)
Scan width 1150km cross track (VNR: VN & P)1400km cross track (IRS: SW & T)Digitalization 12bitPolarization 3 polarization angles for PAlong track direction
Nadir for VN, SW and T, +45 deg and -45 deg for P
On-board calibration
VN: Solar diffuser, LED, Lunar cal maneuvers, and dark current by masked pixels and nighttime obs.
SW: Solar diffuser, LED, Lunar, and dark current by deep space window
T: Black body and dark current by deep space window
Multi-angle obs. for 673.5nm and 868.5nm
250m over the Land or coastal area, and 1km over offshore
option
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Visible and Near Infrared Radiometer (VNR)VNR Non-Polarized (NP) sensor
24deg FOV each for 3 NP sensors. (total 70deg, nadir looking) 11 lines Band pass filter(BPF) on the 11 line 6000pix CCD
VNR Polarized (PL) sensor 55dev FOV with +/-45deg tilting mechanism. (forward, backward and nadir looking) 3 polarization filter on the same design CCD with NP sensor for 3 pol. directions
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SGLI VNR Current Status
Integration
Alignment
SRU-ELU Interface
Radiometric
Thermal vacuum
Vib. & Acoustic
Final performance
VNR SRU
Geometric
Radiometric
Vib. & Shock
Stray light
Pol. measurement
PL sub assembly
Thermal vacuum
PL sub-unitNP sub-unit
Geometric
Vib & Shock
Radiometric
Pol. sensitivity
Stray light
NP sub assembly
Thermal vacuum
NP/P
L se
nsor
Pha
se
completed completed ongoing
←NOW
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Current Status
VNR SRU Onboard Configuration
+Xflight direction
+Ydeep space
+Zearth
VNR SRU
PL NP
March 2016, TSUKUBA
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NP/PL sensor Performance Test by CollimatorGeometric testPolarization sensitivity of NP sensorMuller Matrix for PL sensor Stray light test / Stray light correction model
Rotation Stage : 6-axis (3-linear, 3-rotation)
Geometric Test
Collimator
Rotation Stage
NP sensor
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Radiometric Test (Integrating Sphere)
Radiometric Performance Test by Integrating Sphere ; BaSO4, Spectralon(option)Radiometric test for NP/PL sensorRadiometric test for SRU
Integrating Sphere
Simple rotation stage
NP sensor
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Thermal Vacuum Test
Thermal Vacuum TestGeometric test for NP/PL sub-unitRadiometric test for NP/PL sub-unit
Collimator and Rotation stage are setting in the 6mφ Space chamber in TSUKUBATest condition : 6 (2-ambient, 4-vacuum)
6m Space chamber
IR panels
Collimator
Rotation stage
Sub-Unit
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CCD view angle measurements and verificationAmbient and Thermal Vacuum environment
NoteView angles are stable in thermal vacuum condition. (20~30℃)The deviation between ambient and vacuum is due to the change of focal length.The data for geometric model are acquired.
Geometric Performance (Alignment)
ambient1nominal1coldhotnominal2ambient2
-100
-50
0
50
100
-100-50050100
θy(
arcs
ec)
θx(arcsec)
p60 234pixel
-100
-50
0
50
100
-100-50050100
θy(
arcs
ec)
θx(arcsec)
m60 239pixel -100
-50
0
50
100
-100-50050100
θy(
arcs
ec)
θx(arcsec)
pm0 3000pixel
-100
-50
0
50
100
-100-50050100
θy(
arcs
ec)
θx(arcsec)
p60 5765pixel
-100
-50
0
50
100
-100-50050100
θy(
arcs
ec)
θx(arcsec)
m60 5760pixel
vacuum
ambient
Deviation between ambient and vacuum(about 250m for PL-1km)
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MTF defocusFollowing figures show the MTF defocus trend data. Data point : PL2 sensor, +60° of pol. angle, +27.5° of view angle
NOTEMTF defocus is stable in thermal vacuum condition. (20~30℃)MTF peak is almost 0 defocusing position, it means CCD position is suitable. MTF value attains high resolution of >80%.
Geometric Performance (MTF)
The ambient data are the corrected value due to the vacuum shift of focal length
40
50
60
70
80
90
100
-0.3 -0.2 -0.1 0 0.1 0.2 0.3
MT
F[%
]
Defocusing Position [mm]
p60 +27.5°CT
40
50
60
70
80
90
100
-0.3 -0.2 -0.1 0 0.1 0.2 0.3M
TF
[%]
Defocusing Position [mm]
ambient1nominal1coldhotnominal2ambient2
p60 +27.5°AT
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Radiometric Performance (Linearity)
Linearity errorTest condition : TVT nominal2 data, 0.3Lstd ~ Lmax of radiancePlot data : worst deviation values
CommentThe data satisfies within 2%. (requirement)The final data will acquire at the final performance test of SRU PFT.
0.0%
0.5%
1.0%
1.5%
2.0%
2.5%
3.0%
3.5%
4.0%
VN1 VN2 VN3 VN4 VN5 VN6 VN7 VN8 VN9 VN10VN11
Lin
eari
ty E
rror
NPRNPNNPLSpec
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Radiometric Performance (SNR)
SNRPL sub-unit TVT results in TVT tests.
CommentThe SNR data satisfies >500.(SNR 500 comes form polarization accuracy requirements)The final data will acquire at the final performance test of SRU PFT.
0
500
1000
1500
2000
2500
3000
3500
4000
0 50 100 150 200 250 300 350
S/N
Radiance [W/m2/str/um]
PL2 @TVT nominal2
+60°0°‐60°LstdTarget
0100200300400500600700800900
1000
nom1 cold hot nom2 amb2
S/N
@L
std
PL1_+60°
PL1_0°
PL1_-60°
PL2_+60°
PL2_0°
PL2_-60°
Target
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Polarization Sensitivity for NP sensor
Polarization measurements using the linear polarizer.a) Polarization sensitivity b) Polarization direction
Polarization sensitivity exceeds3% target in RED and NIR channelsas predicted from EM test results. Sensitivity Model req.
in the retrieval algorithm.
0.94
0.96
0.98
1
1.02
1.04
1.06
0 90 180 270 360
Nor
mal
ized
out
put
Rotation angle[deg]
Polarization Uniformity of NPR VN10 +12deg
Measured value
Fitting curve0%
1%
2%
3%
4%
5%
-12 -6 0 6 12
Pola
riza
tion
sens
itivi
ty
View angle[deg]
Polarization sensitivity of NPR VN10
60
70
80
90
100
110
120
-12 -6 0 6 12
Pola
riza
tion
angl
e (°
)
View angle[deg]
Polarization angle of NPR VN10
0.0%
1.0%
2.0%
3.0%
4.0%
5.0%
VN1 VN2 VN3 VN4 VN5 VN6 VN7 VN8 VN9 VN10VN11
Pmax, Pmin NPR PmaxNPN Pmax
NPL Pmax
NPR Pmin
NPN Pmin
NPL Pmin
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Polarization Sensitivity for NP sensor (Model)
Model parameter ρc, ρmax for Stokes Q and U componets
chxy1tan max2
max2
22
yxyx
ch
chl
Qcos 2
1 cos 21 sin 21 cos 2
ρc : Pol. sensitivity of CCD+BPFρl : Pol. sensitivity of telescopeρmax : Pol. sensitivity of telescope (maximum)xch : channel (pixel) location for AT directiony : pixel location for CT directionymax : pixel location for CT direction (maximum)
-U
-U
+U
+U
-Q-Q
+Q
+Q
x_axis
y_axis
6000pixel1pixel
xch
-y
θ
Imaging plane
45°
Coordinate definition
0.0%
0.5%
1.0%
1.5%
2.0%
VN1 VN2 VN3 VN4 VN5 VN6 VN7 VN8 VN9 VN10 VN11
NPR
NPN
NPL
ρmax
-1.0%
0.0%
1.0%
2.0%
3.0%
4.0%
VN1 VN2 VN3 VN4 VN5 VN6 VN7 VN8 VN9 VN10 VN11
NPR
NPN
NPL
ρc
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Modeling errors from 5 view angles data (3 for model, 2 for verification)
ResultsQ, U modeling are realized with sufficientaccuracy comparing to the req.
Relative errors between bands :
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Target AccuracyPol. ratio (ΔP/Pstd) :
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Conclusion
Test results of VNR-SRU PFM met the requirement.
Precise sensor models are analyzed for the data processingGeometric model
Radiometric gain
Polarization sensitivity model of NP sensor
Mueller Matrix for PL sensor
The final VNR test is now ongoing before the delivery to thesatellite system.Mechanical Environmental Test (Vibration and Acoustic Excitation)
Final Performance Test (Integrating Sphere, Calibration Test , … etc)
Target launch in 2017