Terra MODIS surface reflectance band 1-4-3 data from the MOD09CMG product across the globe, August 9, 2018.
View full-size imageThe MOD09CMG Version 6 product provides an estimate of the surface spectral reflectance of Terra Moderate Resolution Imaging Spectroradiometer (MODIS) Bands 1 through 7, resampled to 5600 meter (m) pixel resolution and corrected for atmospheric conditions such as gasses, aerosols, and Rayleigh scattering. The MOD09CMG data product provides 25 layers including MODIS bands 1 through 7; Brightness Temperature data from thermal bands 20, 21, 31, and 32; along with Quality Assurance (QA) and observation bands. This product is based on a Climate Modeling Grid (CMG) for use in climate simulation models.
Validation at stage 3 has been achieved for all MODIS Surface Reflectance products. Further details regarding MODIS land product validation for the MOD09 data products are available from the MODIS Land Team Validation site.
| Characteristic | Description |
|---|---|
| Collection | Terra MODIS |
| DOI | 10.5067/MODIS/MOD09CMG.006 |
| File Size | 515 MB |
| Temporal Resolution | Daily |
| Temporal Extent | 2000-02-24 to 2023-02-17 |
| Spatial Extent | Global |
| Coordinate System | Geographic Latitude and Longitude |
| Datum | N/A |
| File Format | HDF |
| Geographic Dimensions | Global |
| Characteristic | Description |
|---|---|
| Number of Science Dataset (SDS) Layers | 25 |
| Columns/Rows | 7200 x 3600 |
| Pixel Size | 5600 m |
| SDS Name | Description | Units | Data Type | Fill Value | No Data Value | Valid Range | Scale Factor |
|---|---|---|---|---|---|---|---|
| Coarse Resolution Surface Reflectance Band 1 | Surface Reflectance Band 1 (620-670 nm) | N/A | 16-bit signed integer | -28672 | N/A | -100 to 16000 | 0.0001 |
| Coarse Resolution Surface Reflectance Band 2 | Surface Reflectance Band 2 (841-876 nm) | N/A | 16-bit signed integer | -28672 | N/A | -100 to 16000 | 0.0001 |
| Coarse Resolution Surface Reflectance Band 3 | Surface Reflectance Band 3 (459-479 nm) | N/A | 16-bit signed integer | -28672 | N/A | -100 to 16000 | 0.0001 |
| Coarse Resolution Surface Reflectance Band 4 | Surface Reflectance Band 4 (545-565 nm) | N/A | 16-bit signed integer | -28672 | N/A | -100 to 16000 | 0.0001 |
| Coarse Resolution Surface Reflectance Band 5 | Surface Reflectance Band 5 (1230-1250 nm) | N/A | 16-bit signed integer | -28672 | N/A | -100 to 16000 | 0.0001 |
| Coarse Resolution Surface Reflectance Band 6 | Surface Reflectance Band 6 (1628-1652 nm) | N/A | 16-bit signed integer | -28672 | N/A | -100 to 16000 | 0.0001 |
| Coarse Resolution Surface Reflectance Band 7 | Surface Reflectance Band 7 (2105-2155 nm) | N/A | 16-bit signed integer | -28672 | N/A | -100 to 16000 | 0.0001 |
| Coarse Resolution Solar Zenith Angle | Solar Zenith Angle | Degree | 16-bit signed integer | 0 | N/A | 1 to 18000 | 0.01 |
| Coarse Resolution View Zenith Angle | View Zenith Angle | Degree | 16-bit signed integer | 0 | N/A | 1 to 18000 | 0.01 |
| Coarse Resolution Relative Azimuth Angle | Relative Azimuth Angle | Degree | 16-bit signed integer | 0 | N/A | -18000 to 18000 | 0.01 |
| Coarse Resolution Ozone | Ozone Resolution | cm atm | 8-bit unsigned integer | 0 | N/A | 1 to 255 | 0.0025 |
| Coarse Resolution Brightness Temperature Band 20 | Band 20 Brightness Temperature (3.360-3.840 μm) | Kelvin | 16-bit unsigned integer | 0 | N/A | 1 to 40000 | 0.01 |
| Coarse Resolution Brightness Temperature Band 21 | Band 21Brightness Temperature (3.929-3.989 μm) | Kelvin | 16-bit unsigned integer | 0 | N/A | 1 to 40000 | 0.01 |
| Coarse Resolution Brightness Temperature Band 31 | Band 31 Brightness Temperature (10.780-11.280 μm) | Kelvin | 16-bit unsigned integer | 0 | N/A | 1 to 40000 | 0.01 |
| Coarse Resolution Brightness Temperature Band 32 | Band 32 Brightness Temperature (11.770-12.270 μm) | Kelvin | 16-bit unsigned integer | 0 | N/A | 1 to 40000 | 0.01 |
| Coarse Resolution Granule Time | Granule time of day | Hours | 16-bit signed integer | 0 | N/A | 1 to 2355 | N/A |
| Coarse Resolution Band 3 Path Radiance | Band 3 Radiance | N/A | 16-bit signed integer | -28672 | N/A | -100 to 16000 | 0.0001 |
| Coarse Resolution QA | Quality Assurance | Bit Field | 32-bit unsigned integer | 0 | N/A | 1 to 1073741824 | N/A |
| Coarse Resolution Internal CM | Internal Cloud Mask | Bit Field | 16-bit unsigned integer | 0 | N/A | 1 to 8191 | N/A |
| Coarse Resolution State QA | State Quality Assurance | Bit Field | 16-bit unsigned integer | 0 | N/A | 1 to 65535 | N/A |
| Coarse Resolution Number Mapping | Number Mapping Cloud/Snow | Bit Field | 32-bit unsigned integer | 0 | N/A | 1 to 2097151 | N/A |
| number of 500m pixels averaged b3-7 | Number of 500m pixels used in average | N/A | 16-bit unsigned integer | 0 | N/A | 1 to 200 | N/A |
| number of 500m rej. detector | Number of 500m pixels rejected for use | N/A | 8-bit unsigned integer | 0 | N/A | 1 to 100 | N/A |
| number of 250m pixels averaged b1-2 | Number of 250m pixels used in b1-2 average | N/A | 16-bit unsigned integer | 0 | N/A | 1 to 640 | N/A |
| n pixels averaged | Number of pixels used in average | N/A | 8-bit unsigned integer | 0 | N/A | 1 to 40 | N/A |
The Coarse Resolution QA, Internal CM, State QA, and Number Mapping layers are 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 these layers.
The bit flags for the Coarse Resolution QA, Internal CM, State QA, and Number Mapping layers are provided in the User Guide in Tables 10, 13, 14, and 15.
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.
Striping due to a dead detector is noticeable for bands 5, 6, and 7 in scenes acquired February 24 through October 31, 2000. Corrections were implemented to reduce the striping in data acquired after November 1, 2000. Users should always check the band quality for dead detectors even though reflectance values may be in the valid range.
The Collection 6 MODIS Land Surface Reflectance product (MOD09) may incorrectly flag retrievals as ‘High Aerosol’ over brighter surfaces and at higher view angles. This will impact the downstream MODIS BRDF/Albedo (MCD43) and Vegetation Index (MOD13 and MYD13) data products which use the aerosol quantity flag to screen out high aerosol values.
Corrections were implemented in Collection 6.1 reprocessing.
For complete information about the MOD09CMG known issues please refer to the MODIS Land Quality Assessment website.