Aerosol by Polarization (ARPL)

Introduction

ARPL Def Optical thickness, Angstrom exponent, and classification of aerosol estimated using polarization bands.
Unit none
ATBD Ver.1 (Nov. 2018)
Ver.2 (2020)

Update contents of Ver2

  • ・Improved the cloud identification using by polarization band
  • ・Improved the snow/ice identification
  • ・Modified QA flag

Stored Physical quantity

Ver1,2 Description
ARAE_pol_land Aerosol_Angstrom_Exponent at 670 nm and 860 nm
AROT_pol_land Aerosol_Optical_Thickness at 670 nm
ARSSA_pol_land Single_Scattering_Albedo at 380 nm
QA_flag

QA_flag information

Ver.1 Ver.2 Ver.1(Sample Image) Ver.2(Sample Image)

Bit ver1 Description ARAE_pol_land_L3_mask* AROT_pol_land_L3_mask* ARSSA_pol_land_L3_mask*
0 no input data 0 = no/ 1 = yes 1 1 1
1 land/water flag 0 = water/ 1= land 0 0 0
2 cloudy/clear flag 0 = clear/ 1= cloud 1 1 1
3 inhomogeneity of reflectance 0 = no/ 1 = yse 1 1 1
4 stray light (VN1,VN8,VN11) 0 = no/ 1 = yes (at least one channel) 0 0 0
5 stray light (SW3) 0 = no/ 1 = yes (at least one channel) 0 0 0
6 Saturation 0 = no/ 1 = yes (at least one channel) 0 0 0
7 smoke(Existence of absorbing aerosols) 0 = no/ 1 = yes 0 0 0
8 scatter angle < 60 or scatter angle > 120 0 = no/ 1 = yes 0 0 0
9 use climate data 0 = no/ 1 = yes 1 1 1
10 TBD 0 0 0
11 TBD 0 0 0
12 TBD 0 0 0
13 TBD 0 0 0
14 TBD 0 0 0
15 TBD 0 0 0

* Bits masked by statistical processing are indicated by 1.

Bit ver2 Description ARAE_pol_land_L3_mask* AROT_pol_land_L3_mask* ARSSA_pol_land_L3_mask*
0 no input data 0 = no/ 1 = yes 1 1 1
1 land/water flag 0 = water/ 1= land 0 0 0
2 cloudy/clear flag 0 = clear/ 1= cloud 1 1 1
3 inhomogeneity of reflectance 0 = no/ 1 = yse 1 1 1
4 stray light (VN1,VN8,VN11) 0 = no/ 1 = yes (at least one channel) 0 0 0
5 stray light (SW3) 0 = no/ 1 = yes (at least one channel) 0 0 0
6 Saturation 0 = no/ 1 = yes (at least one channel) 0 0 0
7 smoke(Existence of absorbing aerosols) 0 = no/ 1 = yes 0 0 0
8 scatter angle < 60 or scatter angle > 120 0 = no/ 1 = yes 0 0 0
9 use climate data 0 = no/ 1 = yes 1 1 1
10 snow flag 0 = no/ 1 = yes 1 1 1
11 cloudy/clear flag by POL data 0 = clear/ 1= cloud 1 1 1
12 TBD 0 0 0
13 TBD 0 0 0
14 TBD 0 0 0
15 TBD 0 0 0

* Bits masked by statistical processing are indicated by 1.

*Download:QA_flag(Ver1) Sample Image
*Download:QA_flag(Ver2) Sample Image

Attribute information

Ver.1 Ver.2

Ver1 Attribute Remarks
Attribute of Image_data
Attribute of Image_data Grid_interval 0.00833333 1km: 0.00833333
Grid_interval_unit deg
Image_projection EQA (sinusoidal equal area) projection from 0-deg longitude
Number_of_lines 1200 1km: 1200
Number_of_pixels 1200
ARAE_pol_land
ARAE_pol_land
16-bit unsigned integer
Data_description Aerosol_Angstrom_Exponent
Slope 0.0001
Offset -1
Spatial_resolution 0.00833333 1km: 0.00833333
Minimum_valid_DN 0
Maximum_valid_DN 32767
Error_DN 65535
Spatial_resolution_unit degree
Unit NA
Mask_for_statistics 525 Detail: QA_flag_information(~L3_mask)
AROT_pol_land
AROT_pol_land
16-bit unsigned integer
Data_description Aerosol_Optical_Thickness
Slope 0.0001
Offset 0
Spatial_resolution 0.00833333 1km: 0.00833333
Minimum_valid_DN 0
Maximum_valid_DN 32767
Error_DN 65535
Spatial_resolution_unit degree
Unit NA
Mask_for_statistics 525 Detail: QA_flag_information(~L3_mask)
ARSSA_pol_land
ARSSA_pol_land
16-bit unsigned integer
Data_description Single_Scattering_Albedo
Slope 0.0001
Offset 0
Spatial_resolution 0.00833333 1km: 0.00833333
Minimum_valid_DN 0
Maximum_valid_DN 32767
Error_DN 65535
Spatial_resolution_unit degree
Unit NA
Mask_for_statistics 525 Detail: QA_flag_information(~L3_mask)
Ver2 Attribute Remarks
Attribute of Image_data
Attribute of Image_data Grid_interval 0.00833333 1km: 0.00833333
Grid_interval_unit deg
Image_projection EQA (sinusoidal equal area) projection from 0-deg longitude
Number_of_lines 1200 1km: 1200
Number_of_pixels 1200
ARAE_pol_land
ARAE_pol_land
16-bit unsigned integer
Slope 0.0001
Data_description Aerosol_Angstrom_Exponent at 670 nm and 860 nm
Offset -1
Spatial_resolution 0.00833333 1km: 0.00833333
Minimum_valid_DN 0
Maximum_valid_DN 32767
Error_DN 65535
Spatial_resolution_unit degree
Unit NA
Mask_for_statistics 3597 Detail: QA_flag_information(~L3_mask)
AROT_pol_land
AROT_pol_land
16-bit unsigned integer
Slope 0.0001
Data_description Aerosol_Optical_Thickness at 670 nm
Offset 0
Spatial_resolution 0.00833333 1km: 0.00833333
Minimum_valid_DN 0
Maximum_valid_DN 32767
Error_DN 65535
Spatial_resolution_unit degree
Unit NA
Mask_for_statistics 3597 Detail: QA_flag_information(~L3_mask)
ARSSA_pol_land
ARSSA_pol_land
16-bit unsigned integer
Slope 0.0001
Data_description Single_Scattering_Albedo at 380 nm
Offset 0
Spatial_resolution 0.00833333 1km: 0.00833333
Minimum_valid_DN 0
Maximum_valid_DN 32767
Error_DN 65535
Spatial_resolution_unit degree
Unit NA
Mask_for_statistics 3597 Detail: QA_flag_information(~L3_mask)

How to use

  • ・Physical quantity=DN*slope + offset
  • ・Valid values are during Minimum_valid_DN~Maximum_valid_DN