MODIS and VIIRS Land Current and Future use

MODIS (and VIIRS Land) Current and Future use of HDF Robert Wolfe NASA Goddard Space Flight Center Code 614. 5, Greenbelt, MD robert. e. wolfe@nasa. gov

Terra and Aqua MODIS • 3 Nadir Spatial Resolutions – 250 m (1, 2), 500 m (3 -7), and 1 km (8 -36) • 4 Focal Plane Assemblies (FPAs) – VIS, NIR, SMIR, and LWIR • 36 Spectral Bands – Reflective solar bands (1 -19, and 26), thermal emissive bands (20 -25, 27 -36) • On-Board Calibrators (OBCs): – – Solar diffuser (SD) SD stability monitor (SDSM) Blackbody (BB) Spectro-radiometric calibration assembly (SRCA) – Space view (SV) • Science Applications Terra (EOS-AM) Launched Dec. 1999 First light Feb. 2000 Aqua (EOS-PM) Launched May 2002 First light June 2002 – Land, oceans, and atmosphere – Nearly 40 science products generated and distributed Page 2

Current MODIS HDF Usage • MODIS Level 1 (L 1), Atmosphere and Land product formats are – – – HDF 4 -EOS structural metadata (swath and grid) ECS core metadata (ODL string) Mostly SDSs and Attributes (some VDATA) Internal compression Geolocation stored in swath products both internally (reduced resolution) and externally (full resolution) • MODIS Oceans (Sea. Wi. FS heritage) product formats are – HDF 4 – “ECS core equivalent” metadata stored as attributes (matches Sea. Wifs format) – Mostly SDSs and Attributes (some VDATA for L 3 intermediate products) – External compression (i. e. gzip) Wolfe - Nov 09 HDF Workshop 3

MODIS HDF 4 Commentary – my views, not official MODIS views • “Simple” HDF Attributes should have been used for both HDF-EOS structural metadata and ECS core metadata If attributes had been used then: – It would have been easier for users to read metadata fields using the standard HDF library (without SDP library) – It would have made it easier for Science Team developers to read/write metadata • Some lessons learned for Terra (and Aqua) were applied to the Aura mission data formats Wolfe - Nov 09 HDF Workshop 4

Planned MODIS HDF Usage • MODIS will (likely) provide products in HDF 5 in 2011 timeframe L 1, Land, Atmosphere: – Initially, HDF 5 will be offered as one format available as a Post-processing option (i. e. like Geo. TIFF) for MODIS Collection 6 products • MODIS Collection 6 reprocessing will start early 2010 and be completed by end of 2010 – – HDF 5 -EOS structural metadata ECS core metadata fields are likely to be stored as simple HDF 5 attributes Internal compression will be used Later, PGEs (science software) I/O may be rewritten to read/write HDF 5 • Oceans – Switch to HDF 5 will be driven by user community • HDF 5 will be used for Aquarius (produced by Sea. Wi. FS group) – Sea. DAS user tool will be modified to read/write HDF 5 as well as HDF 4 Wolfe - Nov 09 HDF Workshop 5

VIIRS Land Bands

VIIRS Visible, NIR and SWIR Bands • bbb – ccc CO 2 O 3 O 2 H 2 O H 2 O CO 2

Current VIIRS Land PEATE HDF Usage • VIIRS Land PEATE converts NOAA IDPS provided products from HDF 5 to HDF 4 to be compatible with MODIS – Aggregates data to L 1/L 2 data to ~5 min. granules – Simple HDF attributes used for metadata • All VIIRS Science Data Record (SDR, L 1) and EDR Environmental Data Record (EDR, L 2/3) software have been converted to run with HDF 4 data – I/O wrapper is used in algorithms – DDR (Diagnostic Data Record, L 2/3) software reads/writes HDF 4 • NASA Direct Broadcast (DB) Laboratory is modifying I/O wrapper to read/write standard IDPS HDF 5 products to support DB community Wolfe - Nov 09 HDF Workshop 8

VIIRS HDF 5 Commentary – my views, not official Land PEATE views • HDF 5 implementation by IDPS has several major flaws – Complex data structures were developed to support aggregation by time and by products – Simple HDF 5 features (dimensions, units, etc. ) are not being used; instead these fields are stored as HDF attributes – Un-aggregated granules are much shorter than 5 minutes (~1 minute) so they are many (many) files to deal with – For SDRs, each band is stored separately, unless specifically ordered as band aggregates by users Wolfe - Nov 09 HDF Workshop 9

Planned VIIRS Land PEATE HDF Usage Note: The VIIRS Land PEATE is funded to help the NASA science team to evaluate the VIIRS SDR and Land EDR products, not to distribute them (or the DDRs) to the general science community • There will likely be a “convergence” MODIS/VIIRS SDR and Land EDR HDF 5 product formats – A “rational” HDF 5 -EOS format will be used (see earlier MODIS Land HDF 5 discussion) – MODIS HDF 4/5 converter will be modified to also work with VIIRS – Likely to be available in the early VIIRS post-launch timeframe (mid 2011) – This will only be available to the general science community if NASA policy changes Wolfe - Nov 09 HDF Workshop 10

Planned VIIRS Ocean PEATE HDF Usage Note: The VIIRS Ocean PEATE is funded to help the NASA science team to evaluate the VIIRS SDR and Land EDR products, not to distribute them (or the DDRs) to the general science community • If the NASA policy changes, there will likely be a “convergence” MODIS/VIIRS Ocean EDR HDF 5 product formats produced by the VIIRS Ocean PEATE (see earlier MODIS Ocean HDF 5 discussion) Wolfe - Nov 09 HDF Workshop 11

MODIS/Aqua Haze over China and Korea Oct. 28, 2009 Wolfe - Nov 09 HDF Workshop 12

Thank you!