Terra Satellite Daily Surface Reflectance Estimates

MODIS/Terra satellite data provides daily, atmospherically corrected estimates of surface reflectance across seven spectral bands. The MOD09GHK product is generated by NASA's LANCEMODIS team using a correction scheme for gases, aerosols, and cirrus clouds. This Level 2G data serves as input for generating vegetation indices, snow cover, and other land surface products.

Use Cases

• Calculate vegetation indices like NDVI using reflectance values from Band 1 (red) and Band 2 (near-infrared).
• Monitor snow and ice cover by analyzing reflectance patterns across the seven spectral bands.
• Detect thermal anomalies and fire activity through changes in surface reflectance over time.
• Model the Bidirectional Reflectance Distribution Function (BRDF) using daily reflectance observations.
• Estimate Fraction of Photosynthetically Active Radiation (FPAR) from atmospherically corrected reflectance data.

Strengths

• Data is atmospherically corrected for gases, aerosols, and thin cirrus clouds using Band 26.
• Product provides surface reflectance estimates for seven MODIS land bands (1-7).
• Data is available in a near real-time (NRT) delivery mode for timely analysis.

Limitations

• Correction may rely on climatology data if specific MODIS water vapor, aerosol, or ozone products are unavailable.
• The 500m spatial resolution of the SIN Grid may be insufficient for fine-scale local studies.
• Product quality depends on Level 1B pixel quality control, which may exclude some observations.

Provenance

Source

NASA MODIS/Terra satellite instrument.

Collection Method

Atmospherically corrected computation from MODIS Level 1B land bands.

Freshness

Daily

Geography

Global