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Vegetation Index EDR from VIIRS on Suomi NPP

Vegetation Index EDR from VIIRS on Suomi NPP. Marco Vargas 1 , Nikolay Shabanov 2 and Tomoaki Miura 3 18 April 2012 VIIRS Cal/Val Workshop. 1 NOAA/NESDIS/STAR 2 IMSG 3 University of Hawaii. VIIRS Vegetation Index EDR Team. NESDIS/STAR (Marco Vargas, Ivan Csiszar , Nikolay Shabanov)

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Vegetation Index EDR from VIIRS on Suomi NPP

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  1. Vegetation Index EDR from VIIRS on Suomi NPP Marco Vargas1, Nikolay Shabanov2 and Tomoaki Miura3 18 April 2012 VIIRS Cal/Val Workshop 1NOAA/NESDIS/STAR 2IMSG 3University of Hawaii

  2. VIIRS Vegetation Index EDR Team • NESDIS/STAR (Marco Vargas, Ivan Csiszar, Nikolay Shabanov) • University of Hawaii (Tomoaki Miura) • Northrop Grumman (Alan Sei)

  3. VIIRS Vegetation Index EDR • EDR description:The VIIRS Vegetation Index EDR produces a top-of-atmosphere (TOA) NDVI and a top-of-canopy (TOC) Enhanced Vegetation Index (EVI). • Current Retrieval Strategy: • The TOA NDVI calculation uses the traditional NDVI formulation with TOA reflectance inputs (375 m resolution bands I1 and I2). • The TOC Enhanced Vegetation Index (EVI) is computed utilizing a combination of 375 m resolution bands (I1 and I2) and one 750 m resolution band, M3.

  4. VIIRS Vegetation Index EDR • Product Status: The algorithm is based on AVHRR and MODIS heritage. No known issues in generating the Vegetation Index products. • Expected Updates: DR 4622 Quality flag for missing input data. Submitted byNeal Baker. Status: open.

  5. VI EDR Sample Images • Sample global TOA-NDVI and TOC EVI images built from VI EDR swath files. • TOC NDVI Images built from Surface Reflectance RIP (IVISR) bands. • Global Weekly Composites using Maximum Value Composite (MVC) technique.

  6. STAR VIIRS VI Project web-site • Intercompason of VI VIIRS-MODIS-AVHRR • Monitoring TOA NDVI, TOC NDVI and TOC EVI • Multiple metrics (TBD- maps, histograms, statistics) http://www.star.nesdis.noaa.gov/smcd/viirs_vi/Monitor.htm

  7. TOC EVI VIIRS vs. MODIS

  8. TOC NDVI VIIRS vs. MODIS

  9. TOC EVI vs. TOC NDVI Relationship for MODIS Reference • MODIS 16 days composite • MOD13A2 • Jan 17-31, 2012

  10. TOC EVI vs. TOC NDVI Relationship for VIIRS beforeCalibration Fix VIIRS daily VIVIO and IVISR Jan 29, 2012 Problem: Anomalously high positive values of TOC EVI for negative TOC NDVI (marked in circles)

  11. TOC EVI vs. TOC NDVI Relationship for VIIRSafterCalibration Fix • VIIRS daily VIVIO and IVISR Mar 04, 2012 Problem: Anomalously high positive values of EVI for negative NDVI (marked in circles)

  12. VIIRS TOC EVI Anomalies Summary • Were substantially reduced after calibration fix in late February 2012 (reduced by the amount and moved to the Northern high latitudes) • Can not be ignored, especially when generating compositing using max VI values, anomalies accumulate • Anomalies can not be explained by physical factors on the ground, as they arise/disapper at the edges of adjacent scans • Anomalies are due to properties of Blue channel, as only TOC EVI has the anomalies, while TOC NDVI does not have them • Need further collaborative investigation between VI and SR team to understand if this due to calibration, SR algorithm or selection of EVI parameters? Is it fixable or EVI should be replaced with other VI? Swath boundary VIVIO TOC EVI, Mar 09, 2012

  13. Backup Slides

  14. Consistency between ADL3.1 and IDPS VI Jan 22, 2012 TOA NDVI TOC EVI

  15. VIIRS Vegetation Index EDR • The Vegetation Index EDR produces the TOA NDVI and TOC EVI on the VIIRS swath. • The Vegetation Index products are based on AVHRR and MODIS heritage . • VIIRS Vegetation products are swath based. • The algorithm ingests TOA SDR reflectances and atmospherically corrected reflectances (from the Surface Reflectance RIP) and calculates TOA NDVI and TOC EVI as follows:

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