Aqua MODIS Level-3 Global Mapped Remote-Sensing Reflectance Near Real-time Data

Near real-time satellite data providing global mapped remote-sensing reflectance (Rrs) at multiple wavelengths. The Ocean Biology DAAC produces this suite using the best-available ancillary data from meteorological and ozone sources. Rrs is the foundational observable used to retrieve products like chlorophyll-a concentration and support water-quality applications.

Use Cases

• Retrieving chlorophyll-a concentration (chlor_a) based on remote-sensing reflectance data.
• Calculating the diffuse attenuation coefficient (Kd_490) based on Rrs values.
• Developing and validating ocean color algorithms based on the foundational Rrs observable.
• Monitoring water quality in coastal and inland waters based on per-pixel quality flags for clouds and aerosols.

Strengths

• Data is produced in near real-time, providing a snapshot from a single orbit.
• Variables are named by their band center (e.g., Rrs_412, Rrs_443), indicating spectral specificity.
• Includes per-file quality flags for land, cloud, sun glint, and high aerosol, aiding data filtering.

Limitations

• Description metadata is limited; actual data quality requires manual inspection after download.
• Column-level documentation is absent; field semantics must be inferred after download.
• Inputs and calibration are described as 'less than optimal' compared to standard science products.

Provenance

Source

OB_CLOUD / Ocean Biology DAAC

Collection Method

Satellite remote sensing from the Aqua MODIS instrument.

Freshness

Near real-time

Geography

Global