BDC Input Data

INPE pioneered the free provision of medium resolution satellite data, releasing images at no cost from the second China-Brazil Earth Resources Satellite (CBERS-2) [2]. The adoption of this policy encouraged the United States Geological Survey (USGS) to make Landsat data available in 2008 [22], which resulted in a greater amount of access and use of orbital images [24]. Nowadays, Landsat program provides the most faraway orbital image series, providing observations since 1972 and is freely available. Also the European Copernicus program made available the access to all users for Sentinel data, such as Sentinel-2A and Sentinel-2B [3]. The free data approach persists to recent days with free data availability from Landsat-8, Sentinel-2, CBERS-4, Terra, Aqua and more. Images from the Landsat-8/OLI, Sentinel-2A/MSI, Sentinel-2B/MSI, CBERS-4/WFI, CBERS-4/MUX, CBERS-4A/WFI, Terra/MODIS and Aqua/MODIS are used as input data in the BDC products.

CBERS-4

The CBERS (China-Brazil Earth Resources Satellites) program is a cooperation between Brazil and China, established in 1988, to supply both countries with multispectral remotely sensed imagery [13]. Currently, CBERS-4 is in operation, since December 2014. CBERS-4 carries four cameras: (i) Panchromatic and Multispectral Camera, (ii) the Multispectral Camera (MUX), (iii) Infrared System (IRS), and ( iv ) the Wide-Field Imager (WFI). The CBERS-4 satellite has a sun-synchronous orbit with an altitude of 778 km. WFI has four spectral bands, blue, green, red and NIR. All WFI bands present spatial resolution of 64 m (nadir). WFI scenes have approximately 866 km of swath width, which enables a temporal resolution of 5 days.

CBERS-4/WFI (and other products) are freely distributed by INPE. Calibration coefficients for CBERS-4 can be found in [12]. The scenes are provided in INPE’s catalog following CBERS WRS. CBERS-4 main characteristics are:

CBERS-4

WFI

MUX

Launch Date

Dez. 7, 2014

Equatorial crossing time

10:30

Swath (km)

866

120

Field of view (\(^{\circ}\))

28.63

4

Spatial Resolution (m)

64

20

Orbit Height (km)

778

Temporal Resolution (days)

5

26

Spectral Bands (\(\mu m\))

blue (B13)

0.450-0.520

0.450-0.520

green (B14)

0.520-0.590

0.520-0.590

red (B15)

0.630-0.690

0.630-0.690

nir (B16)

0.770-0.890

0.770-0.890

CBERS-4A

Currently, CBERS-4A is in operation, since December 2019. CBERS-4A carries three cameras: (i) Wide Panchromatic and Multispectral Camera (WPM), (ii) the Multispectral Camera (MUX), and (iii) the Wide-Field Imager Camera (WFI). The CBERS-4A satellite has a sun-synchronous orbit with an altitude of 628 km. WFI has four spectral bands, blue, green, red and NIR. All WFI bands present spatial resolution of 55 m (nadir). WFI scenes have approximately 684 km of swath width, which enables a temporal resolution of 5 days.

CBERS-4A/WFI (and other products) are freely distributed by INPE. The scenes are provided in INPE’s catalog following CBERS WRS. CBERS-4A main characteristics are:

CBERS-4A/WFI

Launch Date

Dez. 20, 2019

Equatorial crossing time

10:30

Swath (km)

684

Field of view (\(^{\circ}\))

28.63

Spatial Resolution (m)

55

Orbit Height (km)

628

Temporal Resolution (days)

5

Spectral Bands (\(\mu m\))

blue (B13)

0.450-0.520

green (B14)

0.520-0.590

red (B15)

0.630-0.690

nir (B16)

0.770-0.890

AMAZONIA-1

AMAZONIA-1 is in operation since February 2021. AMAZONIA-1 carries a Wide Field Imager (WFI) Camera. The AMAZONIA-1 satellite has a sun-synchronous orbit with an altitude of 752 km. WFI has four spectral bands, blue, green, red and NIR. All WFI bands present spatial resolution of 60 m (nadir). WFI scenes have approximately 740 km of swath width, which enables a temporal resolution of 5 days.

AMAZONIA-1 (and other products) are freely distributed by INPE. The scenes are provided in INPE’s catalog . AMAZONIA-1 main characteristics are:

AMAZONIA/WFI

Launch Date

Feb. 28, 2021

Equatorial crossing time

10:30

Swath (km)

850

Field of view (\(^{\circ}\))

28.63

Spatial Resolution (m)

64

Orbit Height (km)

752

Temporal Resolution (days)

5

Spectral Bands (\(\mu m\))

blue (B13)

0.450-0.520

green (B14)

0.520-0.590

red (B15)

0.630-0.690

nir (B16)

0.770-0.890

Landsat-8

In the late 60s, NASA (National Aeronautics and Space Administration) started the Landsat program to collect data on renewable and non-renewable natural resources on Earth’s surface. Currently, the Landsat program has two operating platforms, the Landsat-7 (in precarious conditions) and Landsat-8, while Landsat-9 has been authorized and is proceeding towards a December 2020 launch [23]. Landsat-8 was launched in February of 2013. The satellite orbits the Earth in near-polar, sun-synchronous orbit, following the World Reference System (WRS-2) at an altitude of approximately 705 km. The satellite carries two sensors: the OLI (Operational Land Imager) sensor and the TIRS (Thermal Infrared Sensor) sensor, which are co-registered [19]. Landsat-8/OLI presents spatial resolution of 30m, regarding bands of the visible, 15m for panchromatic band and 100m for the thermal bands (TIRS). The imaged scenes have 185 km east-west and present temporal resolution of 16 days.

Digital Number (DN) products are freely distributed by USGS in a tiered structure called Collections. Collection-1 includes Level-1 Precision and Terrain (L1TP) corrected data, which is radiometrically calibrated and orthorectified. The products are provided in the UTM projection and can also be ordered as surface reflectance through USGS ESPA interface, which uses the Landsat Surface Reflectance Code (LaSRC) to process the images [20]. Landsat-8 main characteristics are:

Landsat-8/OLI

Launch Date

Feb. 11, 2013

Equatorial crossing time

10:00

Swath (km)

180

Field of view (\(^{\circ}\))

15

Spatial Resolution (m)

30

Orbit Height (km)

705

Temporal Resolution (days)

16

Spectral Bands (\(\mu m\))

coastal (B01)

0.433-0.453

blue (B02)

0.450-0.515

green (B03)

0.525-0.600

red (B04)

0.630-0.680

nir (B05)

0.845-0.885

swir16 (B06)

1.560-1.660

swir22 (B07)

2.100-2.300

cirrus (B09)

1.360-1.390

MODIS

In 1999 and in 2002 NASA launched Terra and Aqua satellites, respectively. Both platforms present the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard. Terra MODIS and Aqua MODIS are at an altitude of approximately 705 km, with a swath width of approximately 2330 km, which implies in viewing the entire Earth’s surface every 1 to 2 days using its 36 spectral bands [10]. MODIS products are freely distributed by NASA and USGS. MODIS main characteristics are:

MODIS

TERRA

AQUA

Launch Date

Nov. 18, 1999

May 4, 2002

Equatorial crossing time

10:30

13:30

Swath (km)

2330

Field of view (\(^{\circ}\))

49.5

Spatial Resolution (m)

250*, 500**, 1000***

Orbit Height (km)

705

Temporal Resolution (days)

2

Spectral Bands (\(\mu m\))

blue (B03)**

0.459-0.479

green (B04)**

0.545-0.565

red (B01)*

0.620-0.670

nir (B02)*

0.841-0.876

swir16 (B06)**

1.628-1.652

swir22 (B07)**

2.105-2.155

cirrus (B26)***

1.360-1.390

water vapor (B18)***

0.931-0.941

Sentinel-2

The Copernicus Sentinel-2 mission is composed by two polar-orbiting satellites. Sentinel-2A was launched in June of 2015, while Sentinel-2B was launched in March of 2017. The satellites are placed in the same sun-synchronous orbit, orbiting the Earth at an altitude of approximately 786 km. Both satellites have a Multi-Spectral Instrument (MSI) onboard. MSI spatial resolution ranges from 10m for the visible and the broad NIR bands, 20m for the red edge, narrow NIR and SWIR bands, to 60m for the atmospheric bands. The imaged scenes have approximately 290 km east-west and, considering both satellites, images of a a same place on the Earth’s surface can be acquired with a difference of 5 days [5].

Sentinel-2/A and Sentinel-2/B products are freely distributed by ESA into tiled areas of approximately 110 km by 110 km, following the UTM-based Military Grid Reference System (MGRS). The ToA products can be used as input to Sen2Cor to perform atmospheric, terrain and cirrus correction [9]. Sentinel-2 main characteristics are:

Sentinel-2/MSI

A

B

Launch Date

Jun. 23, 2015

Mar. 7, 2017

Equatorial crossing time

10:30

Swath (km)

290

Field of view (\(^{\circ}\))

20.6

Spatial Resolution (m)

10*, 20**, 60***

Orbit Height (km)

786

Temporal Resolution (days)

5 (together)

Spectral Bands (\(\mu m\))

coastal (B01***)

0.4292-0.4562

0.4197-0.4647

blue (B02**)

0.4434-0.5414

0.4431-0.5411

green (B03*)

0.5373-0.5823

0.5360-0.5820

red (B04*)

0.6456-0.6836

0.6454-0.6844

rededge (B05**)

0.6946-0.7136

0.6938-0.7138

rededge (B06**)

0.7315-0.7495

0.7301-0.7481

rededge (B07**)

0.7688-0.7968

0.7657-0.7937

nir (B08**)

0.7603-0.9053

0.7664-0.8994

nir08 (B8A*)

0.8482-0.8812

0.8480-0.8800

nir09 (B09**)

0.9321-0.9581

0.9297-0.9567

cirrus (B10**)

1.3360-1.4110

1.3389-1.4149

swir16 (B11*)

1.5422-1.6852

1.5399-1.6809

swir22 (B12**)

2.0814-2.3234

2.0667-2.3047