NOAA-20 VIIRS: Global Ocean Remote-Sensing Reflectance (RRS) Near Real-time Data

The Ocean Biology DAAC produces near real-time remote-sensing reflectance (RRS) data using the NOAA-20 VIIRS satellite. This foundational observable, measured in units of sr⁻¹, supports the retrieval of ocean color products like chlorophyll-a concentration and diffuse attenuation coefficient. Users must review per-file quality flags for land, cloud, sun glint, and high aerosol conditions, especially in optically complex coastal and inland waters.

Use Cases

• Retrieving chlorophyll-a concentration (chlor_a) based on remote-sensing reflectance data.
• Estimating the diffuse attenuation coefficient (Kd_490) for water clarity studies based on RRS measurements.
• Developing and validating ocean color algorithms based on the foundational Rrs_λ observable.
• Monitoring water quality and ecosystem health in coastal and inland waters based on reflectance data.

Strengths

• Data is produced in near real-time (NRT), providing a snapshot from a single orbit.
• The Rrs_λ variable is described as the foundational observable for retrieving multiple ocean color geophysical products.

Limitations

• Description metadata is limited; actual data quality requires manual inspection after download.
• The inputs and calibration used for the NRT products are described as 'less than optimal'.
• Row count, column definitions, and file formats are unknown, which may limit suitability assessment.

Provenance

Source

Ocean Biology DAAC (OB_CLOUD) via NASA Earthdata (nasa_earthdata)

Collection Method

Satellite remote sensing from the NOAA-20 VIIRS instrument.

Freshness

Near real-time (NRT)

Geography

Global