Detailed Reports on the Validationof the SGLI Products

3．Atmosphere Products

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3.1 Evaluation Summary
ProductReleasethresholdStandard
accuracy

Targetaccuracy

Status*1

10% (withCloud
whole-skyflag/Classification camera)

Incl. below cloud Incl. below cloudamountamount☆

Classified cloud
fraction

20% (on solarirradiance)

15% (on solarirradiance)

10% (on solarirradiance)☆

Cloud top
temp/height

1K

3 K/2 km (toptemp/height)

1.5 K/1 km(temp/height)◎Water cloudOT/effectiveradius
Ice cloud opticalthickness
Aerosol over theoceanLand aerosol bynear ultra violet
Aerosol by
Polarization

Evaluation Methods

Comparison with in-situ observation (sky-camera images)
for release threshold. Evaluations for standard and target
accuracies were performed as the Classified cloud fraction
products.
Comparison of SGLI-derived solar irradiance using cloud
products including cloud flag, cloud fraction etc. withground-measured solar irradiance.
Evaluation was made as vi-cal. of SGLI TIR bands for the
release threshold. In addition, comparison with othersatellite data for evaluating the achievement of thestandard accuracy.

10%/30%100% (as cloud(CloudOT/radius
50% / 20%liquid water))○Comparison with other satellite (MODIS) data.

30%

70%20%○

Comparison with other satellite (MODIS) data.

0.1 (Monthly
τa_670,865)

0.1 (sceneτa_670,865)

0.05 (sceneτa_670,865)○

Comparison with other satellite (MODIS) data.

0.15 (Monthly
τa_380)0.15 (sceneτa_380)0.1 (sceneτa_380 )○Comparison with in-situ observation and other satellite(MODIS) data.

0.1 (sceneτa_670,865)◎Comparison with in-situ observation and other satellite(MODIS) data.

0.15
0.15 (scene(Monthlyτa_670,τa_670,865)
865)*1 Symbols denote as follows; 〇: the release threshold achieved, ◎: the standard accuracy achieved, ☆: the target accuracy achieved.

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3. Validation Results of Atmosphere Products
3.2 (a) Cloud flag/Classification (CLFG)
Validation Method:-Release Threshold: Overall classification errors are evaluated comparing SGLI derived CLFG with thosederived from sky-camera images (by matching the field of view of SGLI and sky-camera).
Standard and target accuracies: Evaluated as the classified cloud fraction product.

Validation data and condition etc.:-In-situ data: Binary classification of clear/cloudy was applied to sky-camera images using red, green,
and blue band digital data of the images. Sky-area within the field of view of 120 degree circle wasused for the analysis of cloud fraction.
SGLI data: SGLI-derived cloud flag was binary classified into clear and cloudy pixels using the data ofclear probability. The areas within the circle of 6 km from the in-situ camera sites are extracted fromSGLI CLFG images and analyzed to derive cloud fraction to be compared with in-situ data.

Validation period:-Daytime: Apr. 1st to Jul. 7th 2018 for seven sites (Ny-Alesund, Sapporo, Tsukuba (JAXA), Tsukuba(Meteorological Research Institute), Kumamoto, Miyako-jima, Syowa Station at Antarctica).
Nighttime: Apr. 1st to Sep. 1st 2018 for three sites (Sapporo, Tsukuba (JAXA), and Kitami)

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3. Validation Results of Atmosphere Products
3.2 (a) Cloud flag/Classification (CLFG)
Validation Results:Daytime

Binary classification of sky-camera images
DaytimeNighttime

Estimated errors

Release threshold

9.5 % (Day)
8.6 % (Night)

10 %Standard accuracy

Target accuracy

Evaluated as the classified cloud fraction
product.

Release threshold is achieved*（*Standard and Target accuracies are also achieved evaluated as the cloud fraction product）

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3. Validation Results of Atmosphere Products
3.2 (a) Cloud flag/Classification (CLFG)
Validation Results:

Supplemental slides

Results of individual sites
札幌

つくば

つくば

熊本

宮古島 昭和基地

Accuracies*1

NyAlesund(Sapporo)

TKSC

Tsukuba

Kumamoto

Miyako-jima

Syowa St.

AllN

53

2558

25

53

4733

294

UAcloud

100.0

95.0

91.7

100.0

100.0

82.9

86.7

92.9

PAcloud

92.1

90.5

100.0

100.0

82.9

93.5

96.3

92.2

OA

94.3

88.0

94.8

100.0

88.7

83.0

84.8

90.5

精度

全体

*1 In the case of cloud height at 6 km

UA: User’s Accuracy
PA: Producer’s Accuracy

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3. Validation Results of Atmosphere Products
3.2 (a) Cloud flag/Classification (CLFG)

Supplemental slides

Evaluation method: BI-SI method for cloud classificationa) Training datafor clear caseb) Training datafor cloudy cased)c)

ClearCloudy
Fig X1 Example of analysis method of the Logistic regression approach. a) 2D-histogram for clear training data, b) 2Dhistogram for cloudy training data, c) example of the Logistic regression curve, and d) calculated clear probability on the BISI space.

a)

b)

c)

Fig X2 Examples of raw sky-camera images (upper images) and analyzed sky-camera images (lower images) for a)completely clear sky, b) completely cloudy, c) mixture of clear and cloudy.

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3. Validation Results of Atmosphere Products
3.2 (b) Classified cloud fraction (CLFR)

Validation Method:- Overall classification errors are evaluated by comparing SGLI-derived solar
radiation, which is monthly average for every 0.1 degree global grids, within-situ measured solar radiation (monthly average).
Validation data and condition etc.:- Solar radiation was derived using SGLI cloud related products, i.e., cloud flag(CLFG), cloud properties (CLPR), atmospherically corrected land surface
reflectance (RSRF) , and ancillary data (meteorological data, elevation etc.).
- When comparing with in-situ data, only the in-situ data meeting thefollowing conditions were used in order to eliminate variable in-situ data
due to the horizontal heterogeneity of clouds;- The time difference between SGLI and in-situ observation was less than
5 minutes.
- Standard deviation of the in-situ data was less than 10 % of the in-situ
data average.
Validation period:- BSRN： Jul. 1st to Oct. 31st 2018 for 22 sites- SKYNET ： Jul. 1st to Oct. 31st 2018 for 3 domestic sites
別1 - 73. Validation Results of Atmosphere Products
3.2 (b) Classified cloud fraction (CLFR)
Validation Results:
Monthly average

Estimated errors

Release threshold

10 % (as solar radiation)

20% (as solar radiation)

Supplemental: Non-monthly average

SGLI: 0.1 deg. Grid average vs. In-situ instantaneous values

Standard accuracy

Target accuracy

15% (as solar radiation) 10% （as solar radiation)

Release threshold, Standard and Target accuracies are achieved*（*Standard and Target accuracies of cloud flag/classification product are also achieved）

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3.2 (c) Cloud top temperature/Cloud top height (CLTT/CLTH)

Validation Method:- Release threshold: Evaluated as vicarious calibration of SGLI TIR bands.
- Standard and target accuracies: Relative errors are evaluated comparing
SGLI-derived cloud top temperature and height with those derived from insitu (ground and airborne) and/or other satellite products (Terra/MODIS:
MOD06 C6) for uniform liquid clouds with moderate optical thickness.
Validation data and condition etc.:- Only the data of water clouds with MOD06 cloud optical depth larger than
5 and cloud top temperature higher than 270 K were used for comparison.
Validation period:- MOD06：Aug. 22nd to Sep. 14th 2018

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3. Validation Results of Atmosphere Products

3.2 (c) Cloud top temperature /Cloud top height (CLTT/CLTH)
Validation Results:
Cloud top temperature(Land: daytime)

Cloud top height(Land: daytime)

Estimated errors (Ocean, Land)

Release threshold

Standard accuracy

Target accuracy

TIR band Vi. Cal.： 0.55 K
Cloud top temp.: 2.1 K, 2.6 K
Cloud top height: 1.2 km, 0.6 km

1K-3K
2 km

3K
2 km

Release threshold and Standard accuracy are achieved
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3. Validation Results of Atmosphere Products

3.2 (d) Water cloud optical thickness/Water cloud effective radius (CLOT_W/CLER_W)
Validation Method:- Release threshold: Relative errors are evaluated comparing SGLI derived
cloud optical thickness and effective radius with those from other satellite
products (MODIS: MOD06, C6) for clouds of mid- to low latitude regions(monthly average).
- Standard accuracy: Relative errors are evaluated comparing cloud liquidwater converted from SGLI derived cloud optical thickness and effective
radius products with those measured with microwave radiometer on theground.
Validation data and condition etc.:- Only the data of MOD06 data acquired within 30 minutes from SGLI
observations were used for comparison.
Validation period:- MOD06：Aug. 22nd to Sep. 14th 2018

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3. Validation Results of Atmosphere Products

3.2 (d) Water cloud optical thickness/Water cloud effective radius (CLOT_W/CLER_W)
Validation Results:
Water cloud optical thickness

Water cloud effective radius(Left: One-deg. grid average over ocean, Right: zonal average) (Left: One-deg. grid average over ocean, Right: zonal average)

Estimated errors (Ocean, Land)
Optical thickness: 8, 9 %Effective radius: 2, 5 %Cloud liquid water: -, -Release threshold

Standard accuracy

Target accuracy

10 %* (vs. MODIS)
30 %* (vs. MODIS)-

100 % (vs. in-situ obs.)

20% (vs. in-situ obs.)
50% (vs. in-situ obs.)*As monthly average of mid- to low latitude regions

Release threshold is achieved

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3. Validation Results of Atmosphere Products

3.2 (d) Water cloud optical thickness/Water cloud effective radius (CLOT_W/CLER_W)
Validation Results: Global distribution (Monthly average)
SGLI-CLPR

Supplemental slides

MOD06

Watercloudopticalthickness

Water
cloudeffectiveradius

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3. Validation Results of Atmosphere Products
3.2 (e) Ice cloud optical thickness (CLOT_I)

Validation Method:- Release threshold: Relative errors are evaluated comparing SGLI derived
ice cloud optical thickness with those from other satellite products(MODIS: MOD06, C6) for clouds of mid- to low latitude regions (monthlyaverage).
- Standard accuracy: Relative errors are evaluated comparing SGLI derived
ice cloud optical thickness with those measured with sky-radiometers onthe ground.
Validation data and condition etc.:- Only the data of MOD06 data acquired within 30 minutes from SGLI
observations were used for comparison.
Validation period:- MOD06：Aug. 22nd to Sep. 14th 2018

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3. Validation Results of Atmosphere Products
3.2 (e) Ice cloud optical thickness (CLOT_I)
Validation Results:
Over Ocean

Over Land(Left: One-deg. grid average over ocean, Right: zonal average) (Left: One-deg. grid average over ocean, Right: zonal average)

Estimated errors(Ocean, Land)27, 29 %(vs. Other satellite)

Release threshold

Standard accuracy

Target accuracy

30 %(vs. Other satellite)

70 %(Sky-radiometer)

20 %(Sky-radiometer)

Release threshold is achieved
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3. Validation Results of Atmosphere Products
3.2 (e) Ice cloud optical thickness (CLOT_I)

Validation Results: Global distribution (Monthly average)
SGLI-CLPR

Supplemental slides

MOD06

Ice cloudopticalthickness

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3. Validation Results of Atmosphere Products

3.2 (f) Aerosol over ocean and land (Non-polarization/Polarization) (ARNP-O, ARNP-L, ANPL)
Validation Method:

Aerosol over ocean:-Release threshold: Overall RMS errors are evaluated comparing SGLI derived aerosol optical thickness (AOT)with those from other satellite sensors (monthly average).
- Standard accuracy: RMS errors are evaluated comparing SGLI derived AOT with those from other satellite
sensors and shipborne in-situ observations (AERONET/Maritime Aerosol Network) (scene by scene).
Aerosol over land:- Release threshold: RMS errors are evaluated comparing SGLI derived AOT with those from sky-radiometers atground observation network (Skynet and AERONET) and other satellite sensors. (monthly average).
- Standard accuracy: RMS errors are evaluated comparing SGLI derived AOT with those from other satellite
sensors and sky-radiometer at ground observation network (Skynet and AERONET) (scene by scene).

Validation data and condition etc.:•

vs. Sky-radiometer: the SGLI data within 10 km from the sky-radiometer sites were used andaveraged for comparison with the data of sky-radiometers.

Validation period:••MODIS: Sep. 1st to 30th 2018
In-situ (sky-radiometer) data for land products:• Data sources: SKYNET (Chiba Univ., Toyama Univ.), Japan Meteorological Agency, AERONET• Period: Aug. 1st to Oct. 22nd 2018 (for non-polarization AOT products); Aug. 5th to Sep. 30th208 (for Polarization AOT product).
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3. Validation Results of Atmosphere Products

3.2 (f) Aerosol over ocean and land (Non-polarization) (ARNP-O, ARNP-L)
Validation Results: Non-polarization AOTs over ocean and land
AOT over LandAOT over Ocean(Monthly average)
vs. MODIS (DT method)(Monthly average)
vs. MODIS (DT method)

AOT over Land
SGLI 0.1 deg. Grid average
vs. In-situ instantaneous values

Estimated errors

Release threshold

Standard accuracy

Target accuracy

0.09 （ocean-other sat., monthly ave.）0.10（monthly ave.）0.10 （scene）

0.05 （scene）

0.15 （land-other sat., monthly ave.）0.15（land-in-situ, scene）

0.15 （monthly ave.）0.15 （scene）

0.10 （scene）

Release threshold is achieved
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3. Validation Results of Atmosphere Products

3.2 (f) Aerosol over ocean and land (Non-polarization) (ARNP-O, ARNP-L)
Validation Results: Global distribution (Monthly average)＊Upper and lower images indicate different results of MODIS land algorithms
SGLI-ARNP
SGLI-ARNP
vs. MODIS
Ocean: DT
Land: DT

SGLI-ARNP
vs. MODIS
Ocean: DT
Land: DB

MODIS
vs. MODIS
DT-landvs. MODIS DB

Note:• DT：Dark Target algorithm• DB：Deep Blue algorithm

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3. Validation Results of Atmosphere Products
3.2 (f) Aerosol over land (Polarization) (ANPL)

Validation Results: Polarization AOTs over land
Vs. in-situ data (sky-radiometer)（Scene）

Vs. MODIS (monthly ave.)Estimated errors

Release threshold

Standard accuracy

Target accuracy

0.14 (in-situ, scene)
0.15 (other sat., monthly ave.)0.15 （monthly ave.）0.15 （scene）

0.10 （scene）

Release threshold and Standard accuracy are achieved
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3. Validation Results of Atmosphere Products
3.2 (f) Aerosol over land (Polarization) (ANPL)

Validation Results: Global distribution (Monthly average)
SGLI vs. MODIS：AOT September 2018 (Descending)

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