MCD19A1 v061

MODIS/Terra+Aqua Land Surface BRF Daily L2G Global 500 m and 1 km SIN Grid


PI: Alexei Lyapustin

The MAIAC data products have been released with the caveat that the reprocessing for the full mission is expected to continue through early 2023.

Description

The MCD19A1 Version 6.1 data product is a Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua combined Land Surface Bidirectional Reflectance Factor (BRF) gridded Level 2 product produced daily at 500 meter (m) and 1 kilometer (km) pixel resolutions. The MCD19A1 product is corrected for atmospheric gases and aerosols using a Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm that is based on a time series analysis and a combination of pixel- and image-based processing. The MODIS MAIAC Land Surface BRF products provide an estimate of the surface spectral reflectance as it would be measured at ground-level in the absence of atmospheric scattering or absorption.

The MCD19A1 MAIAC Surface Reflectance data product includes 31 Science Dataset (SDS) layers: surface reflectance for bands 1-12, BRF uncertainty for bands 1-2, Quality Assessment (QA) bits at 1 km, surface reflectance for bands 1-7 at 500 m, cosine of solar zenith angle, cosine of view zenith angle, relative azimuth angle, scattering angle, solar azimuth angle, view azimuth angle, glint angle, RossThick/Li-Sparse (RTLS) volumetric kernel, and RTLS geometric kernel at 5 km. A low-resolution browse image is also included showing surface reflectance band combination 1, 4, 3 created using a composite of all available orbits.

Each SDS layer within each MCD19A1 Hierarchical Data Format 4 (HDF4) file contains a third dimension that represents the number of orbit overpasses. This factor could affect the total number of bands for each SDS layer.

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Characteristics

Improvements/Changes from Previous Versions

  • The Version 6.1 Level-1B (L1B) products have been improved by undergoing various calibration changes that include: changes to the response-versus-scan angle (RVS) approach that affects reflectance bands for Aqua and Terra MODIS, corrections to adjust for the optical crosstalk in Terra MODIS infrared (IR) bands, and corrections to the Terra MODIS forward look-up table (LUT) update for the period 2012 - 2017.
  • A polarization correction has been applied to the L1B Reflective Solar Bands (RSB).
  • The MCD19 Version 6.1 products have added 250 m resolution bands.
  • The previous BRDF product (MCD19A3) was reported once every eight days and the new MCD19A3D is a daily product.
  • MCD19A3D introduces gap-filled NDVI and gap-filled 250 m NBAR.
  • Snow Fraction, Snow Fit, and Snow Grain Size layers were moved from MCD19A1 to the MCD19A3D.
  • There are four additional Climate Modeling Grid (CMG) products: MCD19A1CMGL, MCD19A1GO, MCD19A2CMG, and MCD19A3CMG.

Product Maturity

Validation at stage 1 has been achieved for the MODIS Surface Reflectance product. Further details regarding MODIS land product validation for the MCD19 data products are available from the MODIS Land Team Validation site.

Collection and Granule

Collection

Characteristic Description
CollectionCombined MODIS
DOI10.5067/MODIS/MCD19A1.061
File Size~40 MB
Temporal ResolutionDaily
Temporal Extent2000-02-24 to Present
Spatial ExtentGlobal
Coordinate SystemSinusoidal
DatumN/A
File FormatHDF-EOS
Geographic Dimensions1200 km x 1200 km

Granule

Characteristic Description
Number of Science Dataset (SDS) Layers31
Columns/Rows2400 (500 m) and 1200 (1000 m) x 2400 (500 m) and 1200 (1000 m)
Pixel Size500 m and 1000 m

Layers

SDS Name Description Units Data Type Fill Value No Data Value Valid Range Scale Factor
Sur_refl1 Surface reflectance for band 1 (1 km) N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
Sur_ref2 Surface reflectance for band 2 (1 km) N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
Sur_ref3 Surface reflectance for band 3 (1 km) N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
Sur_ref4 Surface reflectance for band 4 (1 km) N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
Sur_ref5 Surface reflectance for band 5 (1 km) N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
Sur_ref6 Surface reflectance for band 6 (1 km) N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
Sur_ref7 Surface reflectance for band 7 (1 km) N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
Sur_ref8 Surface reflectance for band 8 (1 km) N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
Sur_ref9 Surface reflectance for band 9 (1 km) N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
Sur_ref10 Surface reflectance for band 10 (1 km) N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
Sur_ref11 Surface reflectance for band 11 (1 km) N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
Sur_ref12 Surface reflectance for band 12 (1 km) N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
Sigma_BRFn1 BRFn uncertainty over time, for band 1 (1 km) N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
Sigma_BRFn2 BRFn uncertainty over time, for band 2 (1 km) N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
Status_QA QA bits (1 km) N/A 16-bit unsigned integer 0 N/A 1 to 65535 N/A
Sur_refl_500m1 Surface reflectance 500 m for band 1 (500 m) N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
Sur_refl_500m2 Surface reflectance 500 m for band 2 (500 m) N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
Sur_refl_500m3 Surface reflectance 500 m for band 3 (500 m) N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
Sur_refl_500m4 Surface reflectance 500 m for band 4 (500 m) N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
Sur_refl_500m5 Surface reflectance 500 m for band 5 (500 m) N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
Sur_refl_500m6 Surface reflectance 500 m for band 6 (500 m) N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
Sur_refl_500m7 Surface reflectance 500 m for band 7 (500 m) N/A 16-bit signed integer -28672 N/A -100 to 16000 0.0001
cosSZA Cosine of Solar zenith angle (5 km) N/A 16-bit signed integer -28672 N/A 0 to 10000 0.0001
cosVZA Cosine View zenith angle (5 km) N/A 16-bit signed integer -28672 N/A 0 to 10000 0.0001
RelAZ Relative azimuth angle (5 km) N/A 16-bit signed integer -28672 N/A -18000 to 18000 0.01
Scattering_Angle Scattering Angle (5 km) N/A 16-bit signed integer -28672 N/A -18000 to 18000 0.01
SAZ Solar Azimuth Angle (5 km) N/A 16-bit signed integer -28672 N/A -18000 to 18000 0.01
VAZ View Azimuth Angle (5 km) N/A 16-bit signed integer -28672 N/A -18000 to 18000 0.01
Glint_Angle Glint Angle (5 km) N/A 16-bit signed integer -28672 N/A -18000 to 18000 0.01
Fv RTLS volumetric kernel (5 km) N/A 32-bit floating point -99999 N/A -100 to 100 N/A
Fg RTLS geometric kernel (5 km) N/A 32-bit floating point -99999 N/A -100 to 100 N/A

The MCD19 SDS layers are three dimensional. The total number of bands in each file is contingent upon the number of orbit overpasses (1-2 bands at the equator and up to 30 bands in polar regions). For example, a file with an orbit number of five will contain five bands for each SDS layer (e.g., Snow_Fraction will be recorded in 5 separate instances). Note that at high latitudes, only the first 16 orbits with the largest coverage are selected for processing per day in order to limit the file size.

Orbit information is stored in the Orbit_amount and Orbit_time_stamp attributes in the HDF file. The global metadata attributes of MODIS data products can be viewed in software such as HDFView and Panoply.

Product Quality

Quality assurance information should be considered when determining the usability of data for a particular science application. The ArcGIS MODIS-VIIRS Python Toolbox contains tools capable of decoding quality data layers while producing thematic quality raster files for each quality attribute.

The QC layer is stored in an efficient bit-encoded manner. The unpack_sds_bits executable from the LDOPE Tools is available to the user community to help parse and interpret the QC layers.

Product quality information is described in Section 6 of the User Guide.

Known Issues

Known issues are described in Section 6 of the User Guide. For complete information about known issues please refer to the MODIS/VIIRS Land Quality Assessment website.


About the image

Combined MODIS Surface Reflectance 500 m Bands 1-4-3 data from the MCD19A1 product over part of west Africa, December 21, 2000.

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Documentation

User Guide
Algorithm Theoretical Basis Document (ATBD)
File Specification

Using the Data

Access Data

Citation

DOI: 10.5067/MODIS/MCD19A1.061