Combined MODIS Surface Reflectance Bands 1-4-3 data from the MCD19A1 product over part of west Africa, March 3, 2018.
View full-size imageThe MCD19A1 Version 6 data product is a Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua combined Multi-Angle Implementation of Atmospheric Correction (MAIAC) 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 new 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 34 Science Dataset (SDS) layers: surface reflectance for bands 1-12, BRF uncertainty for bands 1-2, snow fraction, snow grain size, snow fit, 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.
No previous versions.
Validation at stage 1 has been achieved for the MODIS MAIAC products. Further details regarding MODIS land product validation for the MCD19 data products are available from the MODIS Land Team Validation site.
| Characteristic | Description |
|---|---|
| Collection | Combined MODIS |
| DOI | 10.5067/MODIS/MCD19A1.006 |
| File Size | ~37.46 MB |
| Temporal Resolution | Daily |
| Temporal Extent | 2000-02-01 to 2023-02-17 |
| Spatial Extent | Global |
| Coordinate System | Sinusoidal |
| Datum | N/A |
| File Format | HDF-EOS |
| Geographic Dimensions | 1200 km x 1200 km |
| Characteristic | Description |
|---|---|
| Number of Science Dataset (SDS) Layers | 34 |
| Columns/Rows | 2400 (500 m) and 1200 (1000 m) x 2400 (500 m) and 1200 (1000 m) |
| Pixel Size | 500 m and 1000 m |
| 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 |
| Snow_Fraction | Snow fraction (1 km) | N/A | 16-bit signed integer | -28672 | N/A | 0 to 10000 | 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 |
| Snow_Grain_Size | Snow grain diameter (1 km) | mm | 16-bit signed integer | -28672 | N/A | 0 to 32767 | 0.001 |
| Status_QA | QA bits (1 km) | N/A | 16-bit unsigned integer | 0 | N/A | 1 to 65535 | N/A |
| Snow_Fit | Land+Snow linear mixture model RMSE in bands 1,5,7 (1 km) | N/A | 16-bit signed integer | -28672 | N/A | 0 to 30000 | 0.0001 |
| 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 |
| VAZ | View Azimuth 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 |
| 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 at the equator and up to 30 in Polar Regions). For example, a file with an orbit number of five will contain five bands for each SDS layer (i.e. 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.
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 beginning on page 9 of the User Guide.