Ver2. Ocean Products

1

Evaluation Summary
ProductReleasethresholdStandard
accuracy

Target accuracy

Normalized water
50% (<600nm)
30% (<600nm)
2
0.5W/m/str/um
0.25W/m2/str/um
leaving radiance (incl. 60% (443~565nm)(>600nm)(>600nm)cloud detection)
Atmospheric
80%
50%
30%
correction(AOT@865nm)(AOT@865nm)(AOT@865nm)
parameters
Photosynthetically20% (10km/month) 15% (10km/month) 10% (10km/month)available radiation−35~+50%
Chlorophyll-a−60~+150%(offshore),−60~+150%(offshore)concentration−50~+100% (coast)

Evaluation Methods◎

Comparison with in-situ observation data.

○

Comparison with in-situ observation data.

◎

Comparison with in-situ observation data.

○⇒◎

Comparison with in-situ observation data.

−60~+150%−50~+100%○⇒◎Comparison with other satellite data(GOCI).

−60~+150%(offshore)−60~+150%−50~+100%○⇒◎Comparison with in-situ observation andother satellite data (MODIS).

0.8 K (daytime)

0.8 K (day & night 0.6 K (day & nighttime)
time)

☆

Comparison with in-situ observation data.

Total suspended−60~+150%matter concentration (offshore)
Colored dissolved
organic matterSea surface
temperature

Status*1*1 Symbols denote as follows; 〇: the release threshold achieved, ◎: the standard accuracy achieved, ☆: the target accuracy achieved.

2Validation Results of Ocean NWLR Products:
Normalized Water-Leaving Radiance - NWLR
Major Updates of Algorithm:••

Improved aerosol estimation method, sunglint correction method, in-water model
Applied the vicarious calibration of version 2.0

Validation Method:
Validated the accuracies of predicted NWLR data from the SGLI algorithm comparing with insitu data: ship observation, buoy (MOBY and BOUSSOLE) and AERONET-OCQuality Control:••

In-situ data: time difference in ±3 hours to SGLI observation
SGLI data: average of the data passed the following conditions within a 5 by 5 pixel
centered the in-situ point (for details refer to Bailey et al., 2006) :1. 13 or more pixels which satisfies the following conditions: aerosol optical thickness <0.5, solar zenith angle < 70 degrees, NWLR of all channels > 0, CLDAFFCTD flagisn’t set.
2. Median CV (coefficient of variation) computed from NWLR_380-565nm andTaua_865 nm less than 0.15

Period of Validation•January 1, 2018-February 29, 2020
Reference: Bailey, S.W., and Werdell, P.J. (2006). A multi-sensor approach for the onorbit validation of ocean color satellite data products. Rem. Sens. Environ. 102, 12-23.

Validation Results of Ocean Products:
Normalized Water-Leaving Radiance - NWLR
NWLR_530

Achv. Target

Achv. Standard

Achv. Standard

Achv. Target

Achv. Target

N=113

Accuracy:28%

N=721Accuracy:

47%

In-situ nLw [W/m2/sr/μm]

In-situ nLw [W/m2/sr/μm]

NWLR_565

NWLR_670

Achv. Target

Not Achv.
Stnd.
n=722

N=722

Accuracy:

22%

N=659

Accuracy:

0.9 W/m2/sr/um

In-situ nLw [W/m2/sr/μm]

In-situ nLw [W/m2/sr/μm]

N=722

Accuracy:32%
In-situ nLw [W/m2/sr/μm]

N=722

Accuracy:

19%
In-situ nLw [W/m2/sr/μm]

SGLI nLw [W/m2/sr/μm]

NWLR_490
SGLI nLw [W/m2/sr/μm]

NWLR_443
SGLI nLw [W/m2/sr/μm]

NWLR_412
SGLI nLw [W/m2/sr/μm]

NWLR_380

SGLI nLw [W/m2/sr/μm]

SGLI nLw [W/m2/sr/μm]

SGLI nLw [W/m2/sr/μm]

・Ver. 2: Validation Results

N=722

Accuracy:22%
In-situ nLw [W/m2/sr/μm]• NWLR(380nm, 490-565nm) achieved the target accuracies,NWLR(412-443nm) achieved the standard accuracies 。
• NWLR(670 nm) didn't achieved the standard accuracy on coastal
regions. It is a issue to be solved by version 3. However, version 2
accuracy improved than version 1 (1.2→0.9W/m2/sr/um).
• Number of In-situ points increased than the validation result atversion 1 release(ver.1 release: 14-102 points → ver.2 release: 113-722 points).

Validation Result

Release AccuracyStandard Accuracy

Target Accuracy[Ver. 1]30-40 → [Ver. 2] 19-47% (<600nm)

60% (443-565 nm)

50% (<600 nm),

30% (<600 nm)[Ver. 1] 1.2 → [Ver. 2] 0.9W/m /sr/um (>600nm)

N/A2

0.5W/m2/sr/um (>600nm) 0.25W/m2/sr/um (>600nm)

Achieved the standard accuracies (<600 nm)

Validation Results of Ocean NWLR Products :Atmospheric Correction Parameters - ACP
Major Updates of Algorithm:••

Improved aerosol estimation method, sunglint correction method, in-water model
Applied the vicarious calibration of version 2.0

Validation Method:
Validated the accuracy of predicted aerosol optical thickness at 865 nm (Taua_865) from theSGLI algorithm comparing with in-situ data of AERONET-OC

Quality Control:••

In-situ data: time difference in ±3 hours to SGLI observation
SGLI data: average of the data passed the following conditions within a 5 by 5 pixel
centered the in-situ point (for details refer to Bailey et al., 2006) :1. 13 or more pixels which satisfies the following conditions: aerosol optical thickness <0.3, solar zenith angle < 70 degrees, NWLR of all channels > 0, CLDAFFCTD,GAMMA-OUT and OVERITER flags aren’t set.
2. Coefficient of variation for Taua_865 nm less than 0.05

Period of Validation•January 1, 2018-February 29, 2020

Validation Results of Ocean Products:- Atmospheric Correction Parameters: ACPTAUA_865: Ver. 1 [for reference]

TAUA_865: Ver. 2

Achieved
Release Accuracy

Achieved
Release Accuracy

N=98

N=142

Accuracy:80%

Accuracy:79%✓ Kept the release accuracy✓ Increased the validation points than version 1Validation Result

Release AccuracyStandard Accuracy

Target Accuracy[Ver. 1] 80%→ 79% (AOT@865nm)

80% (AOT@865nm)

50% (AOT@865nm)

30% (AOT@865nm)

Achieved the release accuracy

Photosynthetically available radiation
Daily RMS/AVG=21%

8-day RMS/AVG=15%Monthly RMS/AVG=9.5%

Colors indicate difference of the buoy

Yearly RMS/AVG=5.6%

Bias for each buoy; dependency seems small✓ Daily PAR is estimated by instantaneous transmittance from visible channels.
✓ Reference PAR is made from daily SWR observed by buoy, PAR/SWR ratio estimated by Pstar-4 calculation andobjective analysis water vapor data
✓ SGLI PAR will be able to achieve the target accuracy; improvement from Ver.1 is mainly from L1B improvement

Validation result

Release accuracyStandard accuracy

Target accuracy[Ver. 1] 15% (10km/month)→[Ver.2] 9.5% (10km/month)

20% (10km/month)

15% (10km/month)

10% (10km/month)
2.2 - 7

Validation Results of Ocean IWPR Products:
Chlorophyll-a Concentration - CHLA
Major Updates of Algorithm:•None of major updates

Validation Method:
Validated the accuracy of predicted CHLA data from the SGLI algorithm comparing with in-situ
data (High-Performance Liquid Chromatography: HPLC or fluorescence method) of shipobservation

Quality Control:••

In-situ data: time difference in ±3 hours to SGLI observation
SGLI data: average of the data passed the following conditions within a 5 by 5 pixels
centered the in-situ point :1. 13 or more pixels which satisfies the following conditions: aerosol optical thickness <0.5, solar zenith angle < 70 degrees, NWLR of all channels > 0, CLDAFFCTD flag
isn’t set.

Period of Validation•January 1, 2018-February 29, 2020

Validation Results of Ocean IWPR Products:
Chlorophyll-a Concentration - CHLA
CHLA: Ver. 1 [for reference]

CHLA: Ver. 2

Achieved
Standard Accuracy

Achieved
Standard Accuracy

N=135

N=108

Accuracy:-59~142%

Accuracy:-58~140%✓ Increased the validation points(at time of Ver. 1 release: 9 points → 135 points)✓ Achieved the standard accuracy (include the coastal area)
Validation ResultRelease AccuracyStandard Accuracy

Target Accuracy[Ver. 1] -59~142%→[Ver. 2] -58~140%-60~+150% (offshore)-60~+150%-35~+50% (offshore)-50~+100% (coastal)

Achieved the standard accuracy

Validation Results of Ocean IWPR Products:
Total Suspended Matter - TSM
Major Updates of Algorithm:•Improved the empirical formula

Validation Method:
Validated the accuracy of predicted TSM data from the SGLI algorithm comparing with in-situ
data of ship observation

Quality Control:••

In-situ data: time difference in ±3 hours to SGLI observation
SGLI data: average of the data passed the following conditions within a 5 by 5 pixels
centered the in-situ point:
1. 13 or more pixels which satisfies the following conditions: aerosol optical thickness <0.5, solar zenith angle < 70 degrees, NWLR of all channels > 0, CLDAFFCTD flag
isn’t set.

Period of Validation•January 1, 2018-February 29, 2020

Validation Results of Ocean IWPR Products:
Total Suspended Matter - TSM
TSM: Ver. 1 [for reference]

TSM: Ver. 2

Not Achieved
Standard Accuracy

Achieved
Standard Accuracy

N=34

N=19Accuracy:-65~182%

Accuracy:-58~138%✓ Validated for in-situ data (at time of version 1 release, in-situ data comparison
was not possible)✓ Achieved the standard accuracy (issue: continue to validate with wider rangedata)
Validation Result

Release AccuracyStandard Accuracy

Target Accuracy[Ver. 1] -65~182%→[Ver.2] -58~138%-60~+150% (offshore)-60~+150%-50~+100%

Achieved the standard accuracy

Validation Results of Ocean IWPR Products:
Colored Dissolved Organic Matter - CDOM
Major Updates of Algorithm:•Improved the empirical formula

Validation Method:
Validated the accuracy of predicted CDOM data from the SGLI algorithm comparing with in-situ
data of ship observation

Quality Control:••

In-situ data: time difference in ±3 hours to SGLI observation
SGLI data: average of the data passed the following conditions within a 5 by 5 pixel
centered the in-situ point (for details refer to Bailey et al., 2006) :1. 13 or more pixels which satisfies the following conditions: aerosol optical thickness <0.5, solar zenith angle < 70 degrees, NWLR of all channels > 0, CLDAFFCTD flag
isn’t set.
2. Median CV (coefficient of variation) computed from NWLR_380-565nm andTaua_865 nm less than 0.05.

Period of Validation•January 1, 2018-February 29, 2020
Reference: Bailey, S.W., and Werdell, P.J. (2006). A multi-sensor approach for the onorbit validation of ocean color satellite data products. Rem. Sens. Environ. 102, 12-23.

Validation Results of Ocean IWPR Products:
Colored Dissolved Organic Matter - CDOM
CDOM: Ver. 1 [for reference]

CDOM: Ver. 2Achieved
Standard Accuracy

Achieved
Standard Accuracy

N=8The underestimation bias is cased by theaccuracies of the input NWLR. The bias
doesn’t occur when the in-situ NWLR isinputted, as shown below.
Ver. 2 CDOM
inputted in-situ NWLR

N=14Accuracy:-55~121%

Accuracy:-58~139%✓ Increased the validation points(at time of Ver. 1 release: 5points →14 points)✓ Achieved the standard accuracy (include the coastal area)

Accuracy:-47~88%

Validation Result

Release AccuracyStandard Accuracy

Target Accuracy[Ver. 1] -55~121%→[Ver.2] -58~139%-60~+150% (offshore)-60~+150%-50~+100%

Achieved the standard accuracy

Validation Results of Ocean SST Products:
Sea Surface Temperature- SST
Major Updates of Algorithm:••

Improved the cloud mask algorithm (modified cloud mask on coast and inland waters）
Modified the probability density function of cloud mask

Validation Method:
Validated the accuracy of predicted SST data from the SGLI algorithm comparing with in-situdata of iQuam (Ship and buoy observations)

Quality Control:••

In-situ data: bouy data from NOAA/ iQuam passed the following conditions:
1. quality control level on iQuam: iquam_flag=0, quality_level=5
2. time difference in ±30 minutes to SGLI observation
SGLI data: average of the 1km data passed the following conditions within a 5 by 5 pixels(3 km) centered the in-situ point:
1. Standard deviation of the 5 by 5 pixels < 1.0 degrees C
2. Minimum and maximum temperature differences of the 5 by 5 pixels < 3.0 degrees C
3. Temperature difference between SGLI and iQuam < 5.0 degrees C
4. Flag of quality assurance: Good or Acceptable

Period of Validation•January 1, 2018-Decenber 31, 2019

Validation Results of Ocean SST Products:
Sea Surface Temperature- SST
SST (Daytime)

SST (Nighttime)

Achv. Target

Achv. Standard

Accuracy:
0.4℃

Accuracy:0.7℃*) In the night time, more pixels on coastal areas became available bymodified cloud detection algorithm, whereas the accuracy deteriorated by
the slight increase of cloud affected pixels.

Ver. 1Ver. 2

On coastal area, pixels masked on version 1
as shown green of the left figure became
available as shown red of the right figure.

Validation Result

Release AccuracyStandard Accuracy

Target Accuracy[Ver.1] 0.4 → [Ver.2] 0.4 ℃ (D)[Ver.1] 0.5 → [Ver.2] 0.7 ℃ (N)*0.8℃ (Daytime)

0.8℃

0.6℃

Achieved the target accuracy in the daytime andthe standard accuracy in the nighttime