Slide 1

Production, visualization and analysis of large volumes of remote sensing images modeled as multidimensional data cubes for the entire Brazilian territory.

Data Cube

Multidimensional data cubes from analysis-ready data (ARD) of CBERS-4, CBERS-4A, Landsat-8 and Sentinel-2 satellite images

Figure 1. Grids BDC V2
Figure 2. Grids BDC V1

Data cubes are generated from ARD products from the BDC data collections. In the context of the BDC project, a hierarchical grid system was developed each containing differend cell size, to be used according to the spatial resolution of BDC ARD products. The BDC V2 grid system is composed by the grids BDC_SM (Small), which contains 105600m x 105600m cells, BDC_MD (Medium), which contains 211200m x 211200m cells and BDC_LG (Large), which contains 4224400m x 4224400m cells.

BDC grid system version 1 (BDC V1), followed the same hierarquical structure (Small, Medium e Large). However, the grid cells were deffined as 1×1.5, 2×3 e 4×6 degrees respectively. Figure 1 exemplifies BDC grid V2, while Figure 2 exemplifies grid V1.

The temporal composition function calculates or selects the value of a pixel within a time interval on an identity cube. The temporal composition function can be mean, median or Least Cloud-cover First (LCF). For example, given a time interval the average time composition evaluates all free cloud and cloud shadow values, given a cloud mask, and then calculates the final average value for each spectral band. In the case of LCF, a sorting is made based on the useful area of the images, considering the cloud cover and shadow, so the resulting value of the LCF composition is obtained from the first value found, if there is cloud or shadow in the first ordered image, the values of the pixels are taken from the second image and so on. The LCF temporal compositing function was previously called Stack (STK) during BDC products first versions, only the function name was changed, the best pixel selection remains the same. Figure 3 illustrates these procedures.

Least Cloud-cover First

Figure 3 – Least Cloud-cover First (LCF)

BDC products are stored and distributed in COG (Cloud Optimized GeoTIFF) format, the table below illustrates the data cubes generated in the BDC project.

Data cubes generated by the BDC.

Cube CollectionSatelliteSensorsSpatial Resolution (m)Temporal CompositingGridAvailable
CB4-16D-2CBERS-4AWFI6416 days LCFBDC_LG (V2)
LANDSAT-MOZ_30_1M_STK-1Landsat-5/7/8TM/ETM/OLI301 month LCFBDC_MOZ (V1)
LANDSAT-2M-1Landsat-8/9OLI/OLI2302 months LCFBDC_MD (V2)
S2-16D-2Sentinel-2A/2BMSI1016 days LCFBDC_SM (V2)
CB4_64-1CBERS-4AWFI64IdentityBDC_LG (V1)
CB4_64_16D_STK-1CBERS-4AWFI6416 days LCFBDC_LG (V1)
CB4_20_1M_STK-1CBERS-4MUX201 month LCFBDC_MD (V1)
LC8_30-1Landsat-8OLI30IdentityBDC_MD (V1)
LC8_30_16D_STK-1Landsat-8OLI3016 days LCFBDC_MD (V1)
MOD13Q1-6TERRAMODIS25016 days Best PixelSTG
MYD13Q1-6AQUAMODIS25016 days Best PixelSTG
S2_10-1Sentinel 2A/2BMSI10IdentityBDC_SM (V1)
S2-SEN2COR_10_16D-1Sentinel 2A/2BMSI1016 days LCFBDC_SM (V1)
Brazil Data Cube - 2019 - 2023