Vegetation Index (VGI)

Introduction

NDVI, EVI Define Indices indicating vegetation cover and activity such as NDVI and EVI
Unit none
ATBD Ver.1 (Nov. 2018)
SDI Define An index indicating shadow fraction of vegetation area inferred from spectral reflectance.
Unit none
ATBD Ver.1 (Sep. 2014)
Ver.2 (May 2020)

Update contents of Ver2

  • ・Modified the parameter of shadow index calculation
  • ・Modified QA flag

Stored Physical quantity

Ver1,2 Description
EVI Enhanced Vegetation Index
NDVI Normalized Difference Vegetation Index
QA_flag
SDI Shadow Index

QA_flag information

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

Bit ver1 Description EVI_L3_mask* NDVI_L3_mask* SDI_L3_mask*
0 no data 1: VN08 and/or VN11 are error 1 1 1
1 land/water 0: water >50%, 1: land > 50% 0 0 0
2 mixed with land/water 1: land and water > 1% 0 0 0
3 cloud 1: cloud 1 1 1
4 probably cloud 1: probably cloud 0 0 0
5 snow or ice 1: snow or ice 0 0 0
6 no data for EVI 1: no data for EVI 0 0 0
7 no data for SDI 1: no data for SDI 0 0 1
8 bad input for SW 1: bad input for SW 0 0 1
9 bad input for VN 1: bad input for VN 1 0 0
10 solar zenith angle >70 1: sza > 70° 1 1 0
11 sensor zenith angle >45 1: vza > 45° 0 0 0
12 EVI <-0.2 or EVI >1.0 1: EVI < -0.2 or 1.0 < EVI 1 0 0
13 large incident angle 1: cos(incident angle) < 0.1 0 0 0
14 small NDVI 1: NDVI < 0.65 0 0 0
15 anti solar side 1: anti solar side 0 0 0

* Bits masked by statistical processing are indicated by 1.

Bit ver2 Description EVI_L3_mask* NDVI_L3_mask* SDI_L3_mask*
0 no data 1: VN08 and/or VN11 are error 1 1 1
1 land/water 0: water >50%, 1: land > 50% 0 0 0
2 mixed with land/water 1: land and water > 1% 0 0 0
3 cloud 1: cloud 1 1 1
4 probably cloud 1: probably cloud 0 0 0
5 snow or ice 1: snow or ice 0 0 0
6 shadow 1: shadow 1 1 0
7 bad input for NDVI 1: bad input for NDVI 0 1 0
8 bad input for SDI 1: bad input for SDI 0 0 1
9 bad input for EVI 1: bad input for EVI 1 0 0
10 solar zenith angle >70 1: sza > 70° 1 1 0
11 sensor zenith angle >30 1: vza > 30° 0 0 0
12 EVI <-0.2 or EVI >1.0 1: EVI < -0.2 or 1.0 < EVI 1 0 0
13 large incident angle 1: cos(incident angle) < 0.1 0 0 0
14 small NDVI 1: NDVI < 0.65 0 0 0
15 anti solar side 1: anti solar side 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 0.002083333 250m: 0.002083333
Grid_interval_unit deg
Image_projection EQA (sinusoidal equal area) projection from 0-deg longitude
Number_of_pixels 4800 250m: 4800
Number_of_lines 4800
EVI
EVI
16-bit unsigned integer
Error_DN 65535
Minimum_valid_DN 0
Maximum_valid_DN 30000
Slope 0.0001
Offset -1
Spatial_resolution 0.002083333 250m: 0.002083333
Data_description Enhanced Vegetation Index (EVI)
Unit NA
Spatial_resolution_unit degree
Mask_for_statistics 5641 Detail: QA_flag_information(~L3_mask)
NDVI
NDVI
16-bit unsigned integer
Error_DN 65535
Minimum_valid_DN 0
Maximum_valid_DN 20000
Slope 0.0001
Offset -1
Spatial_resolution 0.002083333 250m: 0.002083333
Data_description Normalized Difference Vegetation Index (NDVI)
Unit NA
Spatial_resolution_unit degree
Mask_for_statistics 1033 Detail: QA_flag_information(~L3_mask)
SDI
SDI
16-bit unsigned integer
Error_DN 65535
Minimum_valid_DN 0
Maximum_valid_DN 10000
Slope 1
Offset 0
Spatial_resolution 0.002083333 250m: 0.002083333
Data_description Shadow Index (SI)
Unit NA
Spatial_resolution_unit degree
Mask_for_statistics 393 Detail: QA_flag_information(~L3_mask)
Ver2 Attribute Remarks
Attribute of Image_data
Attribute of Image_data Grid_interval 0.002083333 250m: 0.002083333
Grid_interval_unit deg
Image_projection EQA (sinusoidal equal area) projection from 0-deg longitude
Number_of_pixels 4800 250m: 4800
Number_of_lines 4800
EVI
EVI
16-bit unsigned integer
Error_DN 65535
Minimum_valid_DN 0
Maximum_valid_DN 30000
Slope 0.0001
Offset -1
Spatial_resolution 0.002083333 250m: 0.002083333
Data_description Enhanced Vegetation Index (EVI)
Unit NA
Spatial_resolution_unit degree
Mask_for_statistics 5705 Detail: QA_flag_information(~L3_mask)
NDVI
NDVI
16-bit unsigned integer
Error_DN 65535
Minimum_valid_DN 0
Maximum_valid_DN 20000
Slope 0.0001
Offset -1
Spatial_resolution 0.002083333 250m: 0.002083333
Data_description Normalized Difference Vegetation Index (NDVI)
Unit NA
Spatial_resolution_unit degree
Mask_for_statistics 1225 Detail: QA_flag_information(~L3_mask)
SDI
SDI
16-bit unsigned integer
Error_DN 65535
Minimum_valid_DN 0
Maximum_valid_DN 10000
Slope 1
Offset 0
Spatial_resolution 0.002083333 250m: 0.002083333
Data_description Shadow Index (SI)
Unit NA
Spatial_resolution_unit degree
Mask_for_statistics 265 Detail: QA_flag_information(~L3_mask)

How to use

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