Snow and Ice Physical Properties (SIPR)

[DOI: 10.57746/EO.01gs73b3t54vbanyyszgcvqtsy]
[DOI: 10.57746/EO.01gs73b3v45wngznvj72tfkg36]

Introduction

SIPR	Define	Grain size of snow ice particle in shallow layer derived mainly from SGLI 865nm band reflectance.
	Unit	μm
	ATBD	Ver.1 (Mar. 2016) Ver.2 (May. 2020)

Update contents of Ver.2

・Improved algorithm for solving snow particle size
・Update table of emissivity

Update contents of Ver.3

・Updated training dataset
・Added snow and ice blue-sky albedo (SALB）to Image_data
・Modified Mask_for_statistics

Sample image

File format	Ver.1	Ver.2	Ver.3
hdf5	TBU	SIPRQ(250m)	SIPRQ(250m)
Image	TBU	SGSLQ(250m) SISTQ(250m)	SGSLQ(250m) SISTQ(250m) SALBQ(250m)

Dataset name

Ver.1,2 Ver.3

Data name	Description
SGSL	Snow grain size of shallow layer
SIST	Snow and ice surface temperature based on a model snow
QA_flag

Data name	Description
SGSL	Snow grain size of shallow layer
SIST	Snow and ice surface temperature based on a model snow
SALB	Direct retrievals of broadband blue sky snow albedo
QA_flag

QA_flag information

Ver.1 Ver.2,3 Ver.1(Sample Image) Ver.2,3(Sample Image)

Bit	Data name	SGSL_L3_mask*	SIST_L3_mask*
0	no input data	1	1
1	land/water flag	0	0
2	cloudy/clear flag	0	0
3	day/night(shadow) flag	0	0
4	snow over land or seaice	1	1
5	snow mixed w/t vegetation or bare ice	1	1
6	melting snow over land or seaice	1	1
7	stray light correction (VN)	0	0
8	stray light correction (SW)	0	0
9	stray light correction (IR)	0	0
10	radiance saturation	0	0
11	sun-glint area	0	0
12	missing channel(VN)	0	0
13	missing channel(SW)	0	0
14	missing channel(IR)	0	0
15	reserved	-	-

* Bits masked by statistical processing are indicated by 1.

Please refer to here to the detail information for QA flag.

Bit	ver2	Description	SGSL_L3_mask*	SIST_L3_mask*
0	no input data		1	1
1	land/water flag		0	0
2	cloudy/clear flag		1	1
3	day/night(shadow) flag		1	1
4	snow over land or seaice	111 no snow	1	1
5	snow mixed w/t vegetation or bare ice		1	1
6	melting snow over land or seaice		1	1
7	stray light correction (VN)		0	0
8	stray light correction (SW)		0	0
9	stray light correction (IR)		0	0
10	radiance saturation		0	0
11	sun-glint area		0	0
12	missing channel(VN)		0	0
13	missing channel(SW)		0	0
14	missing channel(IR)		0	0
15	reserved		-	-

* Bits masked by statistical processing are indicated by 1.

Please refer to here to the detail information for QA flag.

*Download:QA_flag(Ver1) Sample Image

*Download:QA_flag(Ver2) Sample Image

Attribute information

Ver.1 Ver.2 Ver.3

Data name	Attribute		Remarks
Attribute of Image_data
Attribute of Image_data	Number_of_lines	4800	250m: 4800 1km: 1200
	Number_of_pixels	4800	250m: 4800 1km: 1200
	Grid_interval	0.00208333	250m: 0.00208333 1km: 0.00833333
	Grid_interval_unit	deg
	Image_projection	L1B reference grid
	Lower_left_latitude	40	Variable
	Lower_left_longitude	130.541
	Lower_right_latitude	40
	Lower_right_longitude	143.595
	Upper_left_latitude	50
	Upper_left_longitude	155.572
	Upper_right_latitude	50
	Upper_right_longitude	171.13
SGSL
SGSL 16-bit unsigned integer	Slope	0.08
	Offset	20
	Data_description	Snow grain size of shallow layer (SGSL): SGSL = slope*DN + offset
	Unit	micrometer
	Maximum_valid_DN	62250
	Minimum_valid_DN	0
	Error_DN	65535
	No_retrieval_DN_(night)	65534
	No_retrieval_DN_(no_main_VN_SW_channels)	65533
	No_retrieval_DN_(no_main_IR_channels)	65532
	No_retrieval_DN_(out_of_parameter_range)	65531
	Mask_for_statistics	113	Detail: QA_flag_information(～L3_mask)
SIST
SIST 16-bit unsigned integer	Slope	0.0005525
	Offset	240
	Data_description	Snow and ice surface temperature based on a model snow (SIST): SIST = slope*DN + offset
	Unit	kelvin
	Maximum_valid_DN	59999
	Minimum_valid_DN	0
	Error_DN	65535
	No_retrieval_DN_(night)	65534
	No_retrieval_DN_(no_main_VN_SW_channels)	65533
	No_retrieval_DN_(no_main_IR_channels)	65532
	No_retrieval_DN_(out_of_parameter_range)	65531
	Mask_for_statistics	113	Detail: QA_flag_information(～L3_mask)

Data name	Attribute		Remarks
Attribute of Image_data
Attribute of Image_data	Number_of_lines	4800	250m: 4800 1km: 1200
	Number_of_pixels	4800	250m: 4800 1km: 1200
	Grid_interval	0.00208333	250m: 0.00208333 1km: 0.00833333
	Grid_interval_unit	deg
	Image_projection	L1B reference grid
	Lower_left_latitude	40	Variable
	Lower_left_longitude	130.541
	Lower_right_latitude	40
	Lower_right_longitude	143.595
	Upper_left_latitude	50
	Upper_left_longitude	155.572
	Upper_right_latitude	50
	Upper_right_longitude	171.13
SGSL
SGSL 16-bit unsigned integer	Slope	0.08
	Offset	20
	Data_description	Snow grain size of shallow layer (SGSL): SGSL = slope*DN + offset
	Unit	micrometer
	Maximum_valid_DN	62250
	Minimum_valid_DN	0
	Error_DN	65535
	No_retrieval_DN_(night)	65534
	No_retrieval_DN_(no_main_VN_SW_channels)	65533
	No_retrieval_DN_(no_main_IR_channels)	65532
	No_retrieval_DN_(out_of_parameter_range)	65531
	Mask_for_statistics	125	Detail: QA_flag_information(～L3_mask)
SIST
SIST 16-bit unsigned integer	Slope	0.0005525
	Offset	240
	Data_description	Snow and ice surface temperature based on a model snow (SIST): SIST = slope*DN + offset
	Unit	kelvin
	Maximum_valid_DN	59999
	Minimum_valid_DN	0
	Error_DN	65535
	No_retrieval_DN_(night)	65534
	No_retrieval_DN_(no_main_VN_SW_channels)	65533
	No_retrieval_DN_(no_main_IR_channels)	65532
	No_retrieval_DN_(out_of_parameter_range)	65531
	Mask_for_statistics	125	Detail: QA_flag_information(～L3_mask)

Data name	Attribute		Remarks
Attribute of Image_data
Attribute of Image_data	Number_of_lines	4800	250m: 4800 1km: 1200
	Number_of_pixels	4800	250m: 4800 1km: 1200
	Grid_interval	0.00208333	250m: 0.00208333 1km: 0.00833333
	Grid_interval_unit	deg
	Image_projection	L1B reference grid
	Lower_left_latitude	40	Variable
	Lower_left_longitude	130.541
	Lower_right_latitude	40
	Lower_right_longitude	143.595
	Upper_left_latitude	50
	Upper_left_longitude	155.572
	Upper_right_latitude	50
	Upper_right_longitude	171.13
SGSL
SGSL 16-bit unsigned integer	Slope	0.08
	Offset	20
	Data_description	Snow grain size of shallow layer (SGSL): SGSL = slope*DN + offset
	Unit	micrometer
	Maximum_valid_DN	62250
	Minimum_valid_DN	0
	Error_DN	65535
	No_retrieval_DN_(night)	65534
	No_retrieval_DN_(no_main_VN_SW_channels)	65533
	No_retrieval_DN_(no_main_IR_channels)	65532
	No_retrieval_DN_(out_of_parameter_range)	65531
	Mask_for_statistics	28797	Detail: QA_flag information (～L3_mask)
SIST
SIST 16-bit unsigned integer	Slope	0.0005525
	Offset	240
	Data_description	Snow and ice surface temperature based on a model snow (SIST): SIST = slope*DN + offset
	Unit	kelvin
	Maximum_valid_DN	59999
	Minimum_valid_DN	0
	Error_DN	65535
	No_retrieval_DN_(night)	65534
	No_retrieval_DN_(no_main_VN_SW_channels)	65533
	No_retrieval_DN_(no_main_IR_channels)	65532
	No_retrieval_DN_(out_of_parameter_range)	65531
	Mask_for_statistics	28797	Detail: QA_flag information (～L3_mask)
SALB
SALB 16-bit unsigned integer	Slope	0.00002
	Offset	0
	Data_description	Direct retrievals of broadband blue sky snow albedo (SALB): SALB = slope*DN + offset
	Unit	No unit
	Maximum_valid_DN	50000
	Minimum_valid_DN	0
	Error_DN	65535
	No_retrieval_DN_(night)	65534
	No_retrieval_DN_(no_main_VN_SW_channels)	65533
	No_retrieval_DN_(no_main_IR_channels)	65532
	No_retrieval_DN_(out_of_parameter_range)	65531
	Mask_for_statistics	28797	Detail: QA_flag information (～L3_mask)

How to use

・Physical quantity＝DN*slope + offset
・Valid values are during Minimum_valid_DN～Maximum_valid_DN
・Snow and Ice Physical Properties (SIPR) algorithm has the following restrictions.(2020/07/28 Update)
- In Snow grain size of shallow layer (SGSL) and Snow and ice surface temperature (SIST) products, the incorrect values are stored in QA flag of some tiles, and the incorrect values are stored in the statistical product.
- Level2 SIPR,
- Level2 Tile statistics SIPR (SGSL, SIST)
- Level3 (SGSL, SIST)
Product version: Ver.2 (2000)

Snow and Ice Physical Properties (SIPR) [DOI: 10.57746/EO.01gs73b3t54vbanyyszgcvqtsy] [DOI: 10.57746/EO.01gs73b3v45wngznvj72tfkg36]