The Committee on Earth Observation Satellites (CEOS), defines validation as the process of assessing, by independent means, the quality of the data products derived from the system outputs.

The MODIS Land Validation Strategy

MODIS Land (MODLAND) product quality is ensured by Calibration, Quality Assurance (QA) and Validation.  The MODIS land validation effort will contribute to and leverage off of international validation activities, helping to establish standards and protocols through close coordination with the CEOS Land Product Validation (LPV) subgroup, under its Working Group on Calibration and Validation (WGCV).

MODLAND uses several validation techniques to develop uncertainty information for its products. These include comparisons with in situ data collected over a distributed set of validation test sites, comparisons with data and products from other sensors (e.g., ASTER, AVHRR, MISR, TM/ETM+), intercomparison of trends derived from independently-obtained reference data, and analysis of process model results.

MODLAND's primary validation technique includes the collection of field and aircraft data, and comparison with these and with products from other satellites.  The infrastructure for these efforts has resulted in the establishment of a semi-permanent array of EOS Land Validation ,  most of which include a flux tower for extended temporal measurement of terrestrial biophysical dynamics over a range of landcover types.  Field data are archived in cooperation with the Oak Ridge DAAC's Mercury system.  Results of all validation activities are conveyed to the end-user through both published literature and the MODLAND product pages.

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Validation Hierarchy

• Stage 1 Validation:  Product accuracy has been estimated using a small number of independent measurements obtained from selected locations and time periods and ground-truth/field program efforts.

• Stage 2 Validation:  Product accuracy has been assessed over a widely distributed set of locations and time periods via several ground-truth and validation efforts.

• Stage 3 Validation:  Product accuracy has been assessed, and the uncertainties in the product well-established via independent measurements made in a systematic and statistically robust way that represents global conditions.

More Validation Background...V2

   Announcements:

• 2008 MODIS Science Team meeting presentations available
• Summary reports and presentations from the GEO/CEOS Workshop on Calibration and Validation Processes - Geneva, October 2007
• MODIS Collection 5 changes
• ESDR White Papers - developed by the NASA Land Measurement Team - view and comment
• TGARS Special Issue on Global Land Product Validation now available

• Terra
• Aqua

   Landsat News

• Landsat Data Continuity Mission (LDCM) (project updates)
• LDCM home
• Landsat-5 Solar Array Anomaly

MODIS Web Organigram

Curator: Jaime Nickeson
NASA Official: Jeff Morisette
Last Updated: September 12, 2008