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Last Update: June 18, 2007

MODIS data archive and distribution and user support is being transitioned from the Goddard Earth Sciences (GES) DAAC to the MODIS Adaptive Processing System (MODAPS) as part of the NASA Earth Observing System Data and Information System (EOSDIS) evolution process. The transition will be completed by the end of FY2006. Details may be found under Transition Issues. Recent events are summarized below and are coordinated with similar announcements on the GES DAAC web site where appropriate:

  • Collection 4 products will be removed from LAADS on August 1, 2007
    • Level 2 products from the MODIS Collection 4 Atmosphere reprocessing campaign will be removed from the LAADS archive on August 1, 2007. This is in keeping with EOSDIS policy that products from an older reprocessing can be deleted 6 months after the completion of a newer version. The first Collection 5 Atmosphere reprocessing was completed January 19, 2007. The Level 3 Atmosphere products from Collection 4 will be retained in the LAADS archive to allow researchers to compare these products with those from the Collection 5 reprocessing campaign.
    • While the majority of recent orders for Level 2 Atmosphere products have been for Collection 5 products, some orders continue to be received for products produced with the older Collection 4 algorithms. If you need Level 2 products from the Collection 4 reprocessing, please order them by July 20, 2007.
    • Please note that products from the Collection 5 reprocessing incorporate the latest algorithm improvements from the MODIS Atmosphere Science Team. These products are described in detail at: http://modis-atmos.gsfc.nasa.gov/.
    • If you need additional assistance or have questions about obtaining Collection 4 or Collection 5 products, please contact MODAPS User Support at modapsuso@sigmaspace.com or 1-866-506-6347 (toll-free - US only).
  • Terra forward processing.(March 30, 2007)
    • Following various complaints from users, it was determined that an erroneous L1B LUT was loaded into operations on January 27, 2007. This LUT mishandled a correction for a noisy detector in band 2. Consequently, most Terra land products (including the combined products) were adversely affected and are being reprocessed. This reprocessing was started on March 22 and will be completed by mid-April. The ongoing Collection 5 land reprocessing was paused in order to provide a machine for this forward reprocessing. Reprocessed products are being exported to the NSIDC and LP DAACs.
  • Aqua Aerosols reprocessing.(March 07, 2007)
    • After discussion by atmospheres discipline staff it was decided to re-start this reprocessing in order to correct the QA flags associated with deep blue algorithm. The reprocessing was re-stared on March 9 and will be completed by the first week of June.
  • Problems with Aqua attitude data (October 20, 2006)
    • The production of Collection 4 and 5 forward processing has been impacted by delays in the delivery of attitude data products and production is 7-12 days behind real time in contrast to the nominal 1-2 days.
    • The problem has been referred to ESDIS.
  • Land Collection 5 Reprocessing Re-start (October 15, 2006)
    • On August 17 the land team decided to re-start the Collection 5 reprocessing due to the large number of PGE changes.
    • Following science testing of the new codes, the reprocessing was re-started at Terra first light on September 8.
    • The reprocessing is proceeding at 3.5-4x and the Terra-only interval is expected to be completed in early-May, 2007.
    • Data products are being sent to the LP and NSIDC DAACs.
    • Reprocessing of the Terra Land Surface Temperature product has been completed for the interval dataday 55-109, 2000. No reprocessing will be performed for the interval dataday 110-213, 2000.
    • It is expected that land forward processing will be converted to Collection 5 starting dataday January 1, 2007.
  • Chunking added for L1B compression (October 10, 2006)
    • Chunking was added for the Collection 5 L1B compression starting at dataday 277 (October 4, 2006) for forward processing and dataday 354 (December 19, 2000) for reprocessing.
    • Many end-user applications were capable of using un-chunked compressed data. However, some applications required the use of a uncompress. The addition of chunking should obviate the need for this un-compress for most of these end-user applications.
  • Compressed L1B files (April 27, 2006)
    • Many HDF files stored in LAADS and the associated data pools are internally compressed using the NCSA tool "hrepack". This includes the L1B data products stored on the data pools and distributed through subscriptions. This compression is transparent to many user applications. However, in some cases it will be necessary to generate uncompressed L1B files in order to get acceptable performance from applications. Examples of these are running downstream L2 PGEs, McIDAS, and some IDL applications (however, ENVI appears to be transparent).
    • hrepack is documented at http://hdf.ncsa.uiuc.edu/tools/hrepack/hrepack.html.
    • The hrepack executable can be downloaded from http://hdf.ncsa.uiuc.edu/release4/obtain.html or ftp://ftp.ncsa.uiuc.edu/HDF/HDF/HDF_Current/bin/.
    • For usage on Unix or Mac Systems:
      • Be sure to make hrepack executable on your system: chmod +x hrepack
      • An example (csh or tcsh) of Unix/Mac commands to uncompress a Level-1B file;

        set file = MYD021KM.A2006110.1815.2006112085606.hdf
        hrepack -i $file -o $file.unpack -t'*:NONE'
        if ( -e $file.unpack && "$status"== "0" ) mv $file.unpack $file
    • If you encounter applications that require un-compression we would appreciate hearing from you at michael.teague@sigmaspace.com in order that we can pass the information forward to other users.

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