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Collection 5 Atmospheres Reprocessing Plan

Last update: December 23, 2010

This data announcement provides user information for the MODIS atmospheres Science Team concerning the following items: the Collection 5 atmospheres reprocessing; the Collection 5 archive and distribution plans, and; the transition of the GES DAAC MODIS functionality to MODAPS. Please send any questions to Sudipta Sarkar at

Collection 5 Production Plans

The start of Collection 5 atmospheres reprocessing was delayed since it was decided to make additional changes to some PGE codes to ensure the use of consistent Aqua and Terra algorithms (MOD04 and MOD06). The phasing of these deliveries was such that Aqua was reprocessed first followed by Terra. The start date for Aqua reprocessing was April 5, 2006 for L1 data products and April 10, 2006 for atmospheres data products. The Aqua reprocessing was completed on July 18, 2006. The Terra reprocessing started on the same day. The expected reprocessing rate is 15x and the scheduled completion date for the Terra reprocessing is December 17, 2006.

The Collection 5 Aqua forward processing started on April 10, 2006 at dataday 091 (April 1, 2006). The Terra forward processing started on July 18, 2006 at dataday 182 (July 1, 2006). Collection 4 forward processing was continued to overlap with Collection 5 at the request of the CERES/FlashFlux project. Aqua Collection 4 forward processing was terminated on dataday 181 (June 30, 2006). It is expected that Terra Collection 4 will be terminated in mid-August 2006. Production details will be available at Production.

Collection 5 Archive and Distribution Plans

All Collection 5 geolocation and atmospheres L2 and L3 data products including cloud mask/profiles will be archived and distributed through the Level 1 and Atmospheres Archive and Distribution System (LAADS). The LAADS URL is The Collection 4 L3 atmospheres data products have also been archived in LAADS and are presently available to users. In addition, (see below) by December, 2006 all of the Collection 4 L2 products will be transferred from the GES DAAC to LAADS.

The atmosphere Science Team has requested the inclusion of certain Collection 5 land data products in the LAADS archive. Albedo products (MCD43A1 and MCD43B1) will be archived. The production of Terra products was started on June 30, 2006 (Collection 5 Land Reprocessing Plan).

Coincident with the start of the Collection 5 atmospheres Aqua reprocessing, Version 3 of the LAADS system was released. This version includes a number of new features requested by the atmospheres users including metadata searches, parameter subsetting for all atmospheres SDS's, and recurring temporal searches. At the same time, the Atmospheres Archive and Distribution System (AADS) was withdrawn. For the months of April and May access to Collection 5 products will be limited to the MODIS Science Team. However, on August 9, 2006 the archive opened to the general user community. At that time all of the Aqua data was stored in the LAADS archive.

The Collection 5 L1B data products for the continental US (defined as 25 deg to 49 deg N and -67 deg to -125 deg W) and Europe (-10 deg W to +30 deg E and 36 deg to 63 deg N) will be archived in LAADS. An Asian region will be added later. The remaining L1B products will not be archived in LAADS but will be temporarily archived in a rolling data pool. The data pool will have an approximate capacity of 300 datadays of L1B, i.e. approximately, the most recent 20 calendar days of reprocessing production. These data may be accessed through LAADS Version 3 or by anonymous FTP. Earlier L1B data will also be available through LAADS but will be generated on a processing-on-demand basis. Details concerning data access will be available through this production web site at Data Access.

Subscriptions for Collection 5 L1 or atmospheres products can be established on MODAPS/LAADS. If you need subscriptions, please send your requirements to Any existing GES DAAC subscriptions for Collection 5 L1B will be transferred to MODAPS automatically as part of the transition process discussed below.

GES DAAC/MODAPS Transition Plans

As part of the transition of the GES DAAC MODIS functionality to MODAPS, Collection 5 atmospheres products will not be archived at the GES DAAC and will only be available through the LAADS. Further, the GES DAAC will only distribute the Collection 4 atmospheres products through December, 2006 and the GES DAAC Collection 4 holdings will be transferred to LAADS over the interval June through December.

The GES DAAC is no longer generating and distributing L1B and cloud mask products for Aqua or for Terra forward processing. However, the GES DAAC is continuing the production and distribution of reprocessed L1B and cloud mask products and will continue to do so until mid-September, 2006 to ensure that MODAPS/LAADS can provide the end users with the same time range of data that are available through the GES DAAC. In order to ensure this continuity, the Collection 5 reprocessing will need to be performed out of time order since the GES DAAC reprocessing has been performed in this manner. Specifically, the intervals from datadays January 1 2005 through the start of Collection 5 forward processing will need to be reprocessed first. Following this, reprocessing will continue starting from first light. After the mid-September date, Terra Collection 5 L1B, geolocation, and cloud mask/profiles products will only be available from MODAPS/LAADS.

MODAPS added user support staff in April. Detailed contact information is available on this MODAPS production web site at User Services. More details concerning the transition plans will also be included at Transition Issues.

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