Sentinel-3 data introduction

Preface

I want to use sentinel-3 data , But I don't know the band parameters , The search found that there was no introduction to this on the Chinese website , I had to go over the wall to check the user guide on the ESA website . For easy reference , Collating ESA's report on S-3 Introduction to .

OLCI brief introduction

S-3 The satellite has two payloads , One is OLCI（ Sea land colorimeter ）, The other is SLSTR（ Land sea surface temperature radiometer ）.
OLCI It is an optical instrument , Used to ENVISAT Of MERIS Provide data continuity .OLCI It is a push broom imaging spectrometer , It uses 300 m The spatial resolution of the ground is 21 Solar radiation reflected by the earth is measured in spectral bands .
OLCI And MERIS The comparison of band settings is as follows ：

Cyan by MERIS The wave band of , yellow by S-3 OLCI To increase the

The product type

1. L1B Class a products
   L1 The product provides the radiance of each band in the image grid and each pixel in the view , As well as OLCI Annotation data associated with pixels .
2. L2 Class a products

• 2 First class land products
  2 The class a land product provides the calculated land and atmospheric geophysical parameters for full resolution and reduced resolution .
  • OL-2-LFR Surface full resolution products
  • OL-2-LRR Surface resolution reduction product
• 2 Grade aquatic products
  2 Class a aquatic products provide water and atmospheric geophysical parameters calculated for full resolution and reduced resolution .

notes ：NRT For near real-time products , It can be delivered three hours after data collection ,NTC It is not a timely product , One month after data collection . You can view the file suffix “NR”,“NT” distinguish .

Product level	Is the user available	describe	Level
OL_1_EFR___	yes	Full resolution atmospheric radiation ceiling	1 level
OL_1_ERR___	yes	Reduced resolution atmospheric emissivity
OL_1_RAC___	no	Dark shift and gain coefficient of radiometric calibration
OL_1_SPC___	no	Wavelength characterization in spectral calibration
OL_2_WFR___	yes	Full resolution water and atmospheric geophysical products	2 level
OL_2_LFR___	yes	Full resolution terrestrial and atmospheric geophysical products
OL_2_WRR___	yes	The resolution of water and atmospheric geophysical products is reduced
OL_2_LRR___	yes	Land and atmospheric geophysical products with reduced resolution

The resolution of the

Spatial resolution ：
FR The spatial resolution is 300m
RR The spatial resolution is 1.2km, In fact, that is FR Through 4*4 Pixel resampling of .

spectral resolution ：
common 21 Band , Range from visible light to near-infrared （400nm~1020nm）.

surface ： OLCI band characteristics

Band	Central wavelength (nm)	bandwidth (nm)	function
Oa01	400	15	Aerosol correction , Improve water component retrieval ？
Oa02	412.5	10	Yellow matter and turbidity
Oa03	442.5	10	Where chlorophyll absorption is greatest ,biogeochemistry, Vegetation
Oa04	490	10	High chlorophyll
Oa05	510	10	chlorophyll , precipitate , turbidity , red tide
Oa06	560	10	Chlorophyll reference band , Minimum absorption valley
Oa07	620	10	Sediment
Oa08	665	10	The second chlorophyll absorption peak , Sediment , Yellow substance , Vegetation
Oa09	673.75	7.5	For improved fluorescence retrieval and to better account for smile together with the bands 665 and 680 nm
Oa10	681.25	7.5	Chlorophyll fluorescence peak , Red edge
Oa11	708.75	10	Chlorophyll fluorescence baseline , Red edge transition
Oa12	753.75	7.5	Oxygen absorption , Vegetation
Oa13	761.25	2.5	Oxygen absorption zone , Aerosol correction
Oa14	764.375	3.75	Atmospheric correction
Oa15	767.5	2.5	O2A used for cloud top pressure, fluorescence over land
Oa16	778.75	15	The atmosphere correction / Aerosol correction
Oa17	865	20	Atmospheric correction / Aerosol correction , a bank of clouds , Pixel co registration
Oa18	885	10	Water vapor absorption reference band .SLSTR The public reference belt of the instrument . Vegetation monitoring
Oa19	900	10	Water vapor absorption / Vegetation monitoring （ Maximum reflectivity ）
Oa20	940	20	Water vapor absorption , Atmospheric correction / Aerosol correction
Oa21	1020	40	Atmospheric correction / Aerosol correction

Add (1)

revisit period

Figure 2: OLCI mean revisit time with a two-satellite configuration, in red 2 days are required to have revisit at equator, in blue less than 0.5 days at high latitude.
notes ： Figure source official User Guide
Official user guide links ： User guide

SLSTR brief introduction

Land sea surface temperature radiometer （SLSTR） It is a dual view scanning temperature radiometer , Can be in low earth orbit （ At an altitude of 800-830 km ） In flight .Sentinel-3A and Sentinel-3B There are two kinds of instruments on the satellite .Sentinel-3 It was part of the Copernicus plan , It is a combat mission .

The product type

• SLSTR L1B Class a products
  Level-1B Products for each view and SLSTR Each pixel in the channel's regular image grid provides radiance and brightness temperature . Besides , It also contains annotation data associated with each image pixel .
• L2 Class a products , Contains five products .
  • Level-2 WCT product Provide single view and dual view , Sea surface temperature of two or three channels , Open only to alliance members
  • Level-2 WST product according to GJRSST standard , Provide L2P Sea surface temperature products
  • Level-2 LST products Provide land surface temperature products
  • Level-2 FRP Provide global （ Including land and water ） Fire radiant power products
  • Level-2 AOD Provide global （ Including land and water ） Aerosol optical thickness products

notes ：NRT For near real-time products , It can be delivered three hours after data collection ,NTC It is not a timely product , One month after data collection . You can view the file suffix “NR”,“NT” distinguish .NTC Better quality .

More about links ：https://sentinels.copernicus.eu/web/sentinel/user-guides/sentinel-3-slstr/product-types

The resolution of the

• Spatial resolution ：
  Solar reflection zone （S1~S6） The spatial resolution is 500m
  Thermal infrared band （S7~S9 and F1-F2） The resolution is 1Km.

• Radiation resolution ：
  common 9 Band , Include VNIR（ The near infrared ）/SWIR（ Shortwave infrared ）/TIR（ thermal infrared ）.

surface ： OLCI band characteristics

Band	Central wavelength (nm)	bandwidth (nm)	function	Comments	Comments
S1	554.27	19.26	Cloud screening , Vegetation monitoring , Aerosol	The near infrared	Solar reflection zone
S2	659.47	19.25	NDVI, Vegetation monitoring , Aerosol	The near infrared	Solar reflection zone
S3	868.00	20.60	NDVI, Cloud tag , Pixel co registration	The near infrared	Solar reflection zone
S4	1374.80	20.80	Cirrus detection on the ground	Shortwave infrared	Solar reflection zone
S5	1613.40	60.68	loud clearing, ice , snow , Vegetation monitoring	Shortwave infrared	Solar reflection zone
S6	2255.70	50.15	Vegetation status and cloud removal	Shortwave infrared	Solar reflection zone
S7	3742.00	398.00	SST,LST,Active fire	thermal infrared （200K-320K）
S8	10854.00	776.00	SST,LST,Active fire	thermal infrared （200K-320K）
S9	12022.50	905.00	SST,LST	thermal infrared （200K-320K）
F1	3742.00	398.00	Movable fire belt ,Active fire	Infrared thermal radiation band
F2	10854.00	776.00	Movable fire belt ,Active fire	Infrared thermal radiation band

More about links ：https://sentinels.copernicus.eu/web/sentinel/user-guides/sentinel-3-slstr/resolutions

revisit period

chart With two satellite configurations SLSTR Average revisit time

Download address

https://scihub.copernicus.eu/dhus/#/home

reference ：
(1)LI Xuwen, ZHANG Yue, SHI Hao, etc. . Based on sentinel -3A satellite OLCI Application of the maximum chlorophyll index in monitoring cyanobacteria bloom in Taihu Lake [J]. China Environmental Monitoring , 2019, 035(003):146-155.