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
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The Collection 4 L3 atmospheres data products have also been archived in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
Subscriptions for Collection 5 L1 or atmospheres products can be established
on MODAPS/LAADS. If you need subscriptions, please send your requirements
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
More details concerning the transition plans will also be included at