================================================================================
Release notes for GFZ Potsdam GRACE L-2 products - version RL04
================================================================================

Note date 2012-07-04
====================

The RL04 GSM products
   GSM-2_2012080-2012110_0029_EIGEN_G---_0004 Apr 2012
as well as the corresponding GAA/B/C/D products have been generated.

With this products the RL04 generation has stopped.
Please use the improved RL05 time series!

Note date 2012-06-22
====================

The RL04 GSM products
   GSM-2_2012032-2012060_0027_EIGEN_G---_0004 Feb 2012
   GSM-2_2012061-2012092_0029_EIGEN_G---_0004 Mar 2012
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2012-04-10
====================

The RL04 GSM products
   GSM-2_2012001-2012032_0030_EIGEN_G---_0004 Jan 2012
   GSM-2_2011346-2012011_0028_EIGEN_G---_0004 Dez 2011
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2012-03-08
====================

The RL04 GSM products
   GSM-2_2011289-2011320_0031_EIGEN_G---_0004 Nov 2011
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2012-01-09
====================

The RL04 GSM products
   GSM-2_2011274-2011305_0030_EIGEN_G---_0004 Oct 2011
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2011-10-25
====================

The RL04 GSM products
   GSM-2_2011244-2011274_0028_EIGEN_G---_0004 Sep 2011
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2011-10-18
====================

The RL04 GSM products
   GSM-2_2011213-2011244_0030_EIGEN_G---_0004 Aug 2011
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2011-08-25
====================

The RL04 GSM products
   GSM-2_2011185-2011213_0027_EIGEN_G---_0004 Jul 2011
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2011-07-05
====================

The RL04 GSM products
   GSM-2_2011121-2011152_0025_EIGEN_G---_0004 MAY 2011
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2011-06-06
====================

The RL04 GSM products
   GSM-2_2011038-2011060_0021_EIGEN_G---_0004 FEB 2011
   GSM-2_2011060-2011090_0024_EIGEN_G---_0004 MAR 2011
   GSM-2_2011091-2011121_0028_EIGEN_G---_0004 APR 2011
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2011-02-28
====================

The RL04 GSM products
   GSM-2_2010335-2010362_0027_EIGEN_G---_0004 Dec 2010 
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2011-01-24
====================

The RL04 GSM products
   GSM-2_2010305-2010335_0030_EIGEN_G---_0004 Nov 2010 
   GSM-2_2010274-2010305_0029_EIGEN_G---_0004 Oct 2010
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2010-12-15
====================

The RL04 GSM products
   GSM-2_2010244-2010274_0029_EIGEN_G---_0004 SEP 2010
   GSM-2_2010244-2010274_0029_EIGEN_GM60_0004 SEP 2010 (see bullet 3 below)
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2010-11-26
====================

The RL04 GSM products
   GSM-2_2010213-2010244_0030_EIGEN_G---_0004 AUG 2010
   GSM-2_2010213-2010244_0030_EIGEN_GM60_0004 AUG 2010 (see bullet 3 below)
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2010-08-13
====================

The RL04 GSM products
   GSM-2_2010182-2010213_0030_EIGEN_G---_0004 JUL 2010
   GSM-2_2010182-2010213_0030_EIGEN_GM60_0004 JUL 2010 (see bullet 3 below)
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2010-08-13
====================

The RL04 GSM products
   GSM-2_2010152-2010182_0029_EIGEN_G---_0004 JUN 2010
   GSM-2_2010152-2010182_0029_EIGEN_GM60_0004 JUN 2010 (see bullet 3 below)
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2010-07-19
====================

The RL04 GSM products
   GSM-2_2010121-2010152_0029_EIGEN_G---_0004 MAY 2010
   GSM-2_2010121-2010152_0029_EIGEN_GM60_0004 MAY 2010 (see bullet 3 below)
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2010-04-21
====================

The RL04 GSM products
   GSM-2_2010032-2010060_0028_EIGEN_G---_0004 FEB 2010
   GSM-2_2010032-2010060_0028_EIGEN_GM60_0004 FEB 2010 (see bullet 3 below)
   GSM-2_2010060-2010091_0029_EIGEN_G---_0004 MAR 2010
   GSM-2_2010060-2010091_0029_EIGEN_GM60_0004 MAR 2010 (see bullet 3 below)
   GSM-2_2010091-2010121_0030_EIGEN_G---_0004 APR 2010
   GSM-2_2010091-2010121_0030_EIGEN_GM60_0004 APR 2010 (see bullet 3 below)
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2010-04-16
====================

The RL04 GSM products
   GSM-2_2010001-2010032_0031_EIGEN_GM60_0004 JAN 2010 (see bullet 3 below)
   GSM-2_2010001-2010032_0031_EIGEN_G---_0004 JAN 2010
as well as the corresponding GAA/B/C/D products have been generated.
For further details please refer to item 3) below!

Note date 2010-03-16
====================

The RL04 GSM products
   GSM-2_2008275-2008306_0030_EIGEN_GM60_0004 OCT 2008
   GSM-2_2008306-2008336_0028_EIGEN_GM60_0004 NOV 2008  
   GSM-2_2008336-2009001_0029_EIGEN_GM60_0004 DEC 2008  
   GSM-2_2009001-2009032_0030_EIGEN_GM60_0004 JAN 2009  
   GSM-2_2009032-2009060_0027_EIGEN_GM60_0004 FEB 2009  
   GSM-2_2009060-2009091_0028_EIGEN_GM60_0004 MAR 2009  
   GSM-2_2009091-2009121_0029_EIGEN_GM60_0004 APR 2009  
   GSM-2_2009121-2009152_0028_EIGEN_GM60_0004 MAY 2009  
   GSM-2_2009152-2009182_0029_EIGEN_GM60_0004 JUN 2009  
   GSM-2_2009182-2009213_0029_EIGEN_GM60_0004 JUL 2009
   GSM-2_2009213-2009244_0030_EIGEN_GM60_0004 AUG 2009
   GSM-2_2009244-2009274_0029_EIGEN_GM60_0004 SEP 2009
   GSM-2_2009274-2009305_0029_EIGEN_GM60_0004 OCT 2009 
   GSM-2_2009305-2009335_0030_EIGEN_GM60_0004 NOV 2009  
   GSM-2_2009335-2010001_0028_EIGEN_GM60_0004 DEC 2009  
   GSM-2_2009335-2010001_0028_EIGEN_G---_0004 DEC 2009
as well as the corresponding GAA/B/C/D products have been generated.
For further details please refer to item 3 below!

Note date 2010-01-18
====================

The RL04 GSM product
   GSM-2_2009305-2009335_0030_EIGEN_G---_0004 Nov 2009
as well as the corresponding GAA/B/C/D products have been generated.
For further details please refer to item 3) below!

Note date 2009-12-21
====================

The RL04 GSM product
   GSM-2_2009274-2009305_0029_EIGEN_G---_0004 Oct 2009
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2009-12-04
====================

The RL04 GSM product
   GSM-2_2009244-2009274_0029_EIGEN_G---_0004 SEP 2009
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2009-10-29
====================

The RL04 GSM product
   GSM-2_2009152-2009182_0029_EIGEN_G---_0004 AUG 2009
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2009-09-29
====================

The RL04 GSM product
   GSM-2_2009152-2009182_0029_EIGEN_G---_0004 JUN 2009
   GSM-2_2009182-2009213_0029_EIGEN_G---_0004 JUL 2009
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2009-08-25
====================

The RL04 GSM product
   GSM-2_2009091-2009121_0029_EIGEN_G---_0004 APR 2009
   GSM-2_2009121-2009152_0028_EIGEN_G---_0004 MAY 2009
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2009-06-18
====================

The RL04 GSM product
   GSM-2_2009060-2009091_0028_EIGEN_G---_0004 MAR 2009
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2009-05-29
====================

The RL04 GSM product
   GSM-2_2009032-2009060_0027_EIGEN_G---_0004 Feb 2009
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2009-04-01
====================

The RL04 GSM product
   GSM-2_2009001-2009032_0030_EIGEN_G---_0004 Jan 2009
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2009-02-18
====================

The RL04 GSM products
   GSM-2_2008336-2009001_0029_EIGEN_G---_0004 Dec 2008
   GSM-2_2008306-2008336_0028_EIGEN_G---_0004 Nov 2008
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2009-01-22
====================

The RL04 GSM product
   GSM-2_2008275-2008306_0030_EIGEN_G---_0004 Oct 2008
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2008-11-17
====================

The RL04 GSM product
   GSM-2_2008245-2008275_0029_EIGEN_G---_0004 Sep 2008
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2008-10-27
====================

The RL04 GSM product
   GSM-2_2008214-2008245_0031_EIGEN_G---_0004 Aug 2008
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2008-09-19
====================

The RL04 GSM product
   GSM-2_2008183-2008214_0030_EIGEN_G---_0004 Jul 2008
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2008-08-28
====================

The RL04 GSM product
   GSM-2_2008153-2008183_0028_EIGEN_G---_0004 Jun 2008
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2008-08-01
====================

The RL04 GSM product
   GSM-2_2008122-2008153_0030_EIGEN_G---_0004 May 2008
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2008-07-10
====================

The RL04 GSM product
   GSM-2_2008092-2008122_0029_EIGEN_G---_0004 Apr 2008
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2008-06-12
====================

The RL04 GSM product
   GSM-2_2008061-2008092_0030_EIGEN_G---_0004 Mar 2008
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2008-04-27
====================

The RL04 GSM product
   GSM-2_2008032-2008061_0026_EIGEN_G---_0004 Feb 2008
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2008-03-06
====================

The RL04 GSM product
   GSM-2_2008001-2008032_0029_EIGEN_G---_0004 Jan 2008
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2008-02-12
====================

Due to the S2 problems with AOD1B RL04 between June 23, 2006 and September 20,
2007 (see newsletter for October 2007), which caused noticeable signals of up to
some mm water-layer equivalent over the oceans; GFZ has reprocessed all monthly
fields between June 2006 and September 2007. Users shall download these products
once again taking into account that 

- Correct GFZ GSM products can be recognized by the additional header comment
  line "CMMNT Generated with correct AOD1B RL04 product (see SDS Newsletter
  October 2007)"
- Correct May and September 2007 have already been provided before (see note
  date 2007-12-20 below and SDS Newsletter for November 2007)
- Some of the GAx products have been reprocessed too (July, September, October
  and December 06), because the number of days used to calculate the
  corresponding GSM product has been changed. Please substitute the old GAx
  products too!
- The December 2006 field has been provided - as before - as constrained solution
  (see also item 3 below)
- The correct filenames for GSM and GAx-products are as follows

   GSM-2_2006152-2006182_0028_EIGEN_G---_0004 Jun 2006 
   GSM-2_2006182-2006212_0027_EIGEN_G---_0004 Jul 2006 GAx
   GSM-2_2006213-2006244_0028_EIGEN_G---_0004 Aug 2006 
   GSM-2_2006244-2006274_0027_EIGEN_G---_0004 Sep 2006 GAx
   GSM-2_2006274-2006305_0027_EIGEN_G---_0004 Oct 2006 GAx
   GSM-2_2006305-2006335_0030_EIGEN_G---_0004 Nov 2006
   GSM-2_2006335-2007001_0028_EIGEN_G---_0004 Dec 2006 GAx
   GSM-2_2006335-2007001_0028_EIGEN_GK2-_0004 Dec 2006 GAx
   GSM-2_2007001-2007032_0027_EIGEN_G---_0004 Jan 2007
   GSM-2_2007032-2007060_0026_EIGEN_G---_0004 Feb 2007
   GSM-2_2007060-2007091_0030_EIGEN_G---_0004 Mar 2007
   GSM-2_2007091-2007121_0027_EIGEN_G---_0004 Apr 2007
   GSM-2_2007121-2007151_0027_EIGEN_G---_0004 May 2007
   GSM-2_2007152-2007182_0029_EIGEN_G---_0004 Jun 2007
   GSM-2_2007182-2007213_0031_EIGEN_G---_0004 Jul 2007
   GSM-2_2007213-2007244_0029_EIGEN_G---_0004 Aug 2007
   GSM-2_2007244-2007274_0029_EIGEN_G---_0004 Sep 2007

Additionally the October, November and December 2007 solutions have been
generated: 

   GSM-2_2007274-2007305_0027_EIGEN_G---_0004 Oct 2007
   GSM-2_2007305-2007335_0025_EIGEN_G---_0004 Nov 2007
   GSM-2_2007335-2008001_0029_EIGEN_G---_0004 Dec 2007

Note date 2007-12-20
====================

The RL04 GSM product
   GSM-2_2007121-2007151_0027_EIGEN_G---_0004 May 2007
   GSM-2_2007244-2007274_0029_EIGEN_G---_0004 Sep 2007
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2007-11-28
====================

The RL04 GSM product
   GSM-2_2007213-2007244_0029_EIGEN_G---_0004 Aug 2007
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2007-11-02
====================

The RL04 GSM product
   GSM-2_2007182-2007213_0031_EIGEN_G---_0004 Jul 2007
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2007-08-23
====================

The RL04 GSM product
   GSM-2_2007152-2007182_0029_EIGEN_G---_0004 Jun 2007
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2007-06-26
====================

The RL04 GSM products
   GSM-2_2007060-2007091_0030_EIGEN_G---_0004 Mar 2007
   GSM-2_2007091-2007121_0027_EIGEN_G---_0004 Apr 2007
as well as the corresponding GAA/B/C/D products have been generated.

Note date 2007-05-15
====================

The GSM products for
   GSM-2_2002213-2002244_0026_EIGEN_G---_0004 Aug 2002
   GSM-2_2002274-2002303_0027_EIGEN_G---_0004 Oct 2002
   GSM-2_2002305-2002335_0019_EIGEN_G---_0004 Nov 2002
   GSM-2_2007001-2007032_0027_EIGEN_G---_0004 Jan 2007
   GSM-2_2007032-2007060_0026_EIGEN_G---_0004 Feb 2007
have been updated because previously these products did NOT contain drift rates
for C21/S21 coefficients (GRDOTA records). Users are strongly recommended to
download these products once again!

Note date 2007-04-13
====================

1) A RL04 time series has been reprocessed for August 2002 until February 2007.
   Missing products for April, May, September and December 2002 as well as for
   January 2003 will be provided soon.
   Starting with February 2007 RL04 substitutes RL03 (after exactly 4 years RL03
   will not be produced anymore). Details on mofifications wrt RL03 can be found
   in the "GFZ L2 Processing Standards Document for Level-2 Product Release
   0004".

   Note: The reference epoch of the low degree and order coefficients that were
   corrected for a secular trend in the processing of the GRACE data (i.e.
   C20, C30, C40 and with RL04 also C21 and S21) is now 01-JAN-2000 for RL04
   (for RL03 it is 01-JAN-1997).

   For each month 6 product files are available (for RL03 5 product files). 
   For example, for the month January 2005, the available products are:

   GSM-2_2005001-2005032_0028_EIGEN_G---_0004.gz
   GSM-2_2005001-2005032_0028_EIGEN_G---_0004.txt
   GAA-2_2005001-2005032_0028_EIGEN_G---_0004.gz
   GAB-2_2005001-2005032_0028_EIGEN_G---_0004.gz
   GAC-2_2005001-2005032_0028_EIGEN_G---_0004.gz
   GAD-2_2005001-2005032_0028_EIGEN_G---_0004.gz (new)

   All products are described in detail below.

2) As of the date of this release 110 monthly unconstrained and 5 constrained
   solutions of RL04 spanning from August 2002 to April 2012 are available:

   GSM-2_2002213-2002244_0026_EIGEN_G---_0004 Aug 2002
   GSM-2_2002274-2002303_0027_EIGEN_G---_0004 Oct 2002
   GSM-2_2002305-2002335_0019_EIGEN_G---_0004 Nov 2002

   GSM-2_2003032-2003060_0019_EIGEN_G---_0004 Feb 2003
   GSM-2_2003060-2003091_0028_EIGEN_G---_0004 Mar 2003
   GSM-2_2003091-2003121_0029_EIGEN_G---_0004 Apr 2003
   GSM-2_2003121-2003142_0019_EIGEN_G---_0004 May 2003
   GSM-2_2003182-2003213_0027_EIGEN_G---_0004 Jul 2003
   GSM-2_2003213-2003244_0028_EIGEN_G---_0004 Aug 2003
   GSM-2_2003244-2003274_0026_EIGEN_G---_0004 Sep 2003
   GSM-2_2003274-2003303_0027_EIGEN_G---_0004 Oct 2003
   GSM-2_2003305-2003335_0027_EIGEN_G---_0004 Nov 2003
   GSM-2_2003335-2004001_0029_EIGEN_G---_0004 Dec 2003

   GSM-2_2004035-2004061_0025_EIGEN_G---_0004 Feb 2004
   GSM-2_2004061-2004092_0028_EIGEN_G---_0004 Mar 2004
   GSM-2_2004092-2004122_0027_EIGEN_G---_0004 Apr 2004
   GSM-2_2004122-2004153_0027_EIGEN_G---_0004 May 2004
   GSM-2_2004154-2004183_0028_EIGEN_G---_0004 Jun 2004
   GSM-2_2004183-2004214_0029_EIGEN_G---_0004 Jul 2004 (see bullet 3 below)
   GSM-2_2004214-2004245_0026_EIGEN_G---_0004 Aug 2004 (see bullet 3 below)
   GSM-2_2004245-2004275_0028_EIGEN_G---_0004 Sep 2004 (see bullet 3 below)
   GSM-2_2004275-2004306_0031_EIGEN_G---_0004 Oct 2004 (see bullet 3 below)
   GSM-2_2004306-2004336_0028_EIGEN_G---_0004 Nov 2004
   GSM-2_2004338-2005001_0026_EIGEN_G---_0004 Dec 2004

   GSM-2_2005001-2005032_0028_EIGEN_G---_0004 Jan 2005
   GSM-2_2005032-2005060_0025_EIGEN_G---_0004 Feb 2005
   GSM-2_2005060-2005091_0029_EIGEN_G---_0004 Mar 2005
   GSM-2_2005091-2005121_0027_EIGEN_G---_0004 Apr 2005
   GSM-2_2005121-2005152_0030_EIGEN_G---_0004 May 2005
   GSM-2_2005152-2005182_0028_EIGEN_G---_0004 Jun 2005
   GSM-2_2005182-2005213_0028_EIGEN_G---_0004 Jul 2005
   GSM-2_2005213-2005244_0028_EIGEN_G---_0004 Aug 2005
   GSM-2_2005244-2005274_0027_EIGEN_G---_0004 Sep 2005
   GSM-2_2005274-2005305_0028_EIGEN_G---_0004 Oct 2005
   GSM-2_2005305-2005333_0026_EIGEN_G---_0004 Nov 2005
   GSM-2_2005338-2005364_0021_EIGEN_G---_0004 Dec 2005

   GSM-2_2006001-2006032_0027_EIGEN_G---_0004 Jan 2006
   GSM-2_2006032-2006060_0023_EIGEN_G---_0004 Feb 2006
   GSM-2_2006060-2006091_0028_EIGEN_G---_0004 Mar 2006
   GSM-2_2006091-2006121_0027_EIGEN_G---_0004 Apr 2006
   GSM-2_2006121-2006151_0028_EIGEN_G---_0004 May 2006
   GSM-2_2006152-2006182_0028_EIGEN_G---_0004 Jun 2006
   GSM-2_2006182-2006212_0028_EIGEN_G---_0004 Jul 2006
   GSM-2_2006213-2006244_0028_EIGEN_G---_0004 Aug 2006
   GSM-2_2006245-2006274_0026_EIGEN_G---_0004 Sep 2006
   GSM-2_2006274-2006305_0028_EIGEN_G---_0004 Oct 2006
   GSM-2_2006305-2006335_0030_EIGEN_G---_0004 Nov 2006
   GSM-2_2006335-2007001_0027_EIGEN_G---_0004 Dec 2006 (see bullet 3 below)

   GSM-2_2007001-2007032_0027_EIGEN_G---_0004 Jan 2007 
   GSM-2_2007032-2007060_0026_EIGEN_G---_0004 Feb 2007
   GSM-2_2007060-2007091_0030_EIGEN_G---_0004 Mar 2007
   GSM-2_2007091-2007121_0027_EIGEN_G---_0004 Apr 2007
   GSM-2_2007121-2007151_0027_EIGEN_G---_0004 May 2007
   GSM-2_2007152-2007182_0029_EIGEN_G---_0004 Jun 2007
   GSM-2_2007182-2007213_0031_EIGEN_G---_0004 Jul 2007
   GSM-2_2007213-2007244_0029_EIGEN_G---_0004 Aug 2007
   GSM-2_2007244-2007274_0029_EIGEN_G---_0004 Sep 2007
   GSM-2_2007274-2007305_0027_EIGEN_G---_0004 Oct 2007
   GSM-2_2007305-2007335_0025_EIGEN_G---_0004 Nov 2007
   GSM-2_2007335-2008001_0029_EIGEN_G---_0004 Dec 2007

   GSM-2_2008001-2008032_0029_EIGEN_G---_0004 Jan 2008
   GSM-2_2008032-2008061_0026_EIGEN_G---_0004 Feb 2008
   GSM-2_2008061-2008092_0030_EIGEN_G---_0004 Mar 2008
   GSM-2_2008092-2008122_0029_EIGEN_G---_0004 Apr 2008
   GSM-2_2008122-2008153_0030_EIGEN_G---_0004 May 2008
   GSM-2_2008153-2008183_0028_EIGEN_G---_0004 Jun 2008
   GSM-2_2008183-2008214_0030_EIGEN_G---_0004 Jul 2008
   GSM-2_2008214-2008245_0031_EIGEN_G---_0004 Aug 2008
   GSM-2_2008245-2008275_0029_EIGEN_G---_0004 Sep 2008
   GSM-2_2008275-2008306_0030_EIGEN_G---_0004 Oct 2008 (see bullet 3 below)
   GSM-2_2008306-2008336_0028_EIGEN_G---_0004 Nov 2008 (see bullet 3 below)
   GSM-2_2008336-2009001_0029_EIGEN_G---_0004 Dec 2008 (see bullet 3 below)

   GSM-2_2009001-2009032_0030_EIGEN_G---_0004 Jan 2009 (see bullet 3 below)
   GSM-2_2009032-2009060_0027_EIGEN_G---_0004 Feb 2009 (see bullet 3 below)
   GSM-2_2009060-2009091_0028_EIGEN_G---_0004 MAR 2009 (see bullet 3 below)
   GSM-2_2009091-2009121_0029_EIGEN_G---_0004 APR 2009 (see bullet 3 below)
   GSM-2_2009121-2009152_0028_EIGEN_G---_0004 MAY 2009 (see bullet 3 below)
   GSM-2_2009152-2009182_0029_EIGEN_G---_0004 JUN 2009 (see bullet 3 below)
   GSM-2_2009182-2009213_0029_EIGEN_G---_0004 JUL 2009 (see bullet 3 below)
   GSM-2_2009152-2009182_0029_EIGEN_G---_0004 AUG 2009 (see bullet 3 below)
   GSM-2_2009244-2009274_0029_EIGEN_G---_0004 SEP 2009 (see bullet 3 below)
   GSM-2_2009274-2009305_0029_EIGEN_G---_0004 Oct 2009 (see bullet 3 below)
   GSM-2_2009305-2009335_0030_EIGEN_G---_0004 Nov 2009 (see bullet 3 below)
   GSM-2_2009335-2010001_0028_EIGEN_G---_0004 DEC 2009 (see bullet 3 below)

   GSM-2_2010001-2010032_0031_EIGEN_G---_0004 JAN 2010 (see bullet 3 below)
   GSM-2_2010032-2010060_0028_EIGEN_G---_0004 FEB 2010 (see bullet 3 below)
   GSM-2_2010060-2010091_0029_EIGEN_G---_0004 MAR 2010 (see bullet 3 below)
   GSM-2_2010091-2010121_0030_EIGEN_G---_0004 APR 2010 (see bullet 3 below)
   GSM-2_2010121-2010152_0029_EIGEN_G---_0004 MAY 2010 (see bullet 3 below)
   GSM-2_2010152-2010182_0029_EIGEN_G---_0004 JUN 2010 (see bullet 3 below)
   GSM-2_2010182-2010213_0030_EIGEN_G---_0004 JUL 2010 (see bullet 3 below)
   GSM-2_2010213-2010244_0030_EIGEN_G---_0004 AUG 2010 (see bullet 3 below)
   GSM-2_2010244-2010274_0029_EIGEN_G---_0004 SEP 2010 (see bullet 3 below)
   GSM-2_2010274-2010305_0029_EIGEN_G---_0004 Oct 2010
   GSM-2_2010305-2010335_0030_EIGEN_G---_0004 Nov 2010 
   GSM-2_2010335-2010362_0027_EIGEN_G---_0004 Dec 2010 

   GSM-2_2011038-2011060_0021_EIGEN_G---_0004 FEB 2011
   GSM-2_2011060-2011090_0024_EIGEN_G---_0004 MAR 2011
   GSM-2_2011091-2011121_0028_EIGEN_G---_0004 APR 2011
   GSM-2_2011121-2011152_0025_EIGEN_G---_0004 MAY 2011
   GSM-2_2011185-2011213_0027_EIGEN_G---_0004 Jul 2011
   GSM-2_2011213-2011244_0030_EIGEN_G---_0004 Aug 2011
   GSM-2_2011244-2011274_0028_EIGEN_G---_0004 Sep 2011
   GSM-2_2011274-2011305_0030_EIGEN_G---_0004 Oct 2011
   GSM-2_2011289-2011320_0031_EIGEN_G---_0004 Nov 2011 (see bullet 8 below)
   GSM-2_2011346-2012011_0028_EIGEN_G---_0004 Dez 2011 (see bullet 8 below)

   GSM-2_2012001-2012032_0030_EIGEN_G---_0004 Jan 2012
   GSM-2_2012032-2012060_0027_EIGEN_G---_0004 Feb 2012
   GSM-2_2012061-2012092_0029_EIGEN_G---_0004 Mar 2012
   GSM-2_2012080-2012110_0029_EIGEN_G---_0004 Apr 2012

3) Because GRACE experienced a 4d repeat cycle between July and October 2004
   (see SDS monthly newsletters) which created instabilities in the quality of
   the GRACE products, also contrained solutions (*GK2-* instead of *G---*) have
   been generated for this period:

   GSM-2_2004183-2004214_0029_EIGEN_GK2-_0004 Jul 2004 
   GSM-2_2004214-2004245_0026_EIGEN_GK2-_0004 Aug 2004
   GSM-2_2004245-2004275_0028_EIGEN_GK2-_0004 Sep 2004
   GSM-2_2004275-2004306_0031_EIGEN_GK2-_0004 Oct 2004

   GFZ has generated unconstrained degree 60 solutions for the period October
   2008 till September 2010 to overcome creeping and notable monthly model
   degradations caused by the 7 day repeat cycle with climax around December
   2009 / January 2010. These additional L2 products are named *GM60* which
   is in agreement with GFZ's unconstrained degree 30 weekly solutions (*GW30*).
   The unconstrained degree 120 solutions are still provided for comparison.
   According to degree variance plots and results of GFZ's evaluation chain,
   it is recommended to use the alternative solutions starting with May
   2009 till now. For the months before, a cut-off of the 120x120 solutions
   at degree 60 delivers approximately the same results as the corresponding
   60x60 solutions. Further information is given in the GRACE SDS Newsletter
   for February 2010.

   GSM-2_2008275-2008306_0030_EIGEN_GM60_0004 OCT 2008
   GSM-2_2008306-2008336_0028_EIGEN_GM60_0004 NOV 2008  
   GSM-2_2008336-2009001_0029_EIGEN_GM60_0004 DEC 2008  
   GSM-2_2009001-2009032_0030_EIGEN_GM60_0004 JAN 2009  
   GSM-2_2009032-2009060_0027_EIGEN_GM60_0004 FEB 2009  
   GSM-2_2009060-2009091_0028_EIGEN_GM60_0004 MAR 2009  
   GSM-2_2009091-2009121_0029_EIGEN_GM60_0004 APR 2009  
   GSM-2_2009121-2009152_0028_EIGEN_GM60_0004 MAY 2009  
   GSM-2_2009152-2009182_0029_EIGEN_GM60_0004 JUN 2009  
   GSM-2_2009182-2009213_0029_EIGEN_GM60_0004 JUL 2009
   GSM-2_2009213-2009244_0030_EIGEN_GM60_0004 AUG 2009
   GSM-2_2009244-2009274_0029_EIGEN_GM60_0004 SEP 2009
   GSM-2_2009274-2009305_0029_EIGEN_GM60_0004 OCT 2009 
   GSM-2_2009305-2009335_0030_EIGEN_GM60_0004 NOV 2009  
   GSM-2_2009335-2010001_0028_EIGEN_GM60_0004 DEC 2009  
   GSM-2_2010001-2010032_0031_EIGEN_GM60_0004 JAN 2010
   GSM-2_2010032-2010060_0028_EIGEN_GM60_0004 FEB 2010
   GSM-2_2010060-2010091_0029_EIGEN_GM60_0004 MAR 2010
   GSM-2_2010091-2010121_0030_EIGEN_GM60_0004 APR 2010
   GSM-2_2010121-2010152_0029_EIGEN_GM60_0004 MAY 2010
   GSM-2_2010152-2010182_0029_EIGEN_GM60_0004 JUN 2010 
   GSM-2_2010182-2010213_0030_EIGEN_GM60_0004 JUL 2010
   GSM-2_2010213-2010244_0030_EIGEN_GM60_0004 AUG 2010 
   GSM-2_2010244-2010274_0029_EIGEN_GM60_0004 SEP 2010

   In December 2006 there was a GPS anomaly on GRACE-B causing a 4 day data gap
   (as of 24-Dec-2006 to 27-Dec-2006) degrading the standard field. Using the
   same methodology as for the months in the 2004 repeat cycle a constrained
   solution (*GK2-* instead of *G---*) has been generated for this month:

   GSM-2_2006335-2007001_0027_EIGEN_GK2-_0004 Dec 2006

   At higher degrees, users will observe that all monthly coefficient values
   of the constrained solutions tend towards the coefficient values from the 
   background mean field EIGEN_GL04C. The lower degree harmonics are variable
   from month to month, and represent the monthly average mass variability, 
   as before.

   Also, the formal errors of these constrained solutions appear to be too
   optimistic. The calibrated errors (*txt) of these constrained solutions are
   identical as for the corresponding unconstrained products.

   CAUTION is advised for these reasons in the use of the five months of
   constrained solutions in conjunction with the un-constrained solutions.
   For example, they cannot be used in a differentially weighted time-series
   analysis. The higher degree terms will tend to show a zero deviation at
   higher degrees relative to EIGEN_GL04C - which might affect scatter analyses.

   The user community has previously found it necessary to apply spatial
   smoothing filters to the un-constrained solutions while extracting mass
   flux estimates. The use of such filters appears still to be necessary,
   though ad hoc experiments suggest that less smoothing is required with the
   constrained fields. In any event, as below, the decision on such smoothing
   filter design is left to the user.

4) Due to increasing errors with increasing harmonic degrees, users are
   discouraged from using the spherical harmonic coefficients past
   approximately degree 90 or 100 in monthly unconstrained fields.

   The use of a suitable truncation or smoothing technique is recommended.
   Examples are available in the literature. The selection of the smoothing
   technique and the highest degree are left to the user's discretion.

   ONLY the formal error standard deviations (sigmas) of the estimated
   geopotential harmonics are contained in the GSM-2* products. Regardless
   of the definitions, the reported standard deviations, when multiplied
   by the scale in the header, still yield only the formal (and NOT calibrated)
   error estimates.

   The calibrated errors of all GSM-2* products are provided as GSM-2*.txt files.
   For each degree/order pair, the square-root of the error variance (the
   diagonal element of the error covariance matrix) is provided, in the same
   convention as the coefficients themselves.
   These error estimates are calibrated using standard methods including
   sub-set and inter-month comparisons. These error estimates remain "best-guess"
   and can (& will) be refined as we receive feedback from data product users, or
   as the error calibration techniques improve.

5) Additionally the corresponding monthly mean AOD products (GAA-2*, GAB-2*
   GAC-2* and GAD-2*) for the same time span as the GSM-2* products have been
   provided. The GAD products are new with RL04 and describe the mean ocean
   bottom pressure variability throughout each month (set land pixels to 0.,
   ocean pixels to OMCT water column plus surface pressure before calculation of 
   spherical harmonics). Details of the definition of the different GAx-2*
   products can be found in the updated AOD1B Product Definition Document.

   The averaging is carried out over a whole number of days - regardless of
   whether full or partial day's data were used in creating the GRACE monthly
   solution.

   Note: The physical constants in the GSM-2* and GAx-2* products have been
   harmonized.

   Note: A re-adding of the GAB-2* product for analysis of e.g. the continental
   hydrological cycle or ice mass variations is no longer necessary!

   Note: The degree 0 and 1 terms of the GAC-2* or GAD-2* products shall not
   be used when re-added to the GSM-2* products!

6) The RL04 series and also this release note will be updated on a regular basis
   within the next months. Please refer to the GRACE monthly SDS newsletters.

7) A RL04 mean field model derived from an accumulation of the whole GRACE data
   set will be provided at a later time. For the moment the user can compute a
   mean field as arithmetic mean of the monthly model coefficients spanning
   an integer number of years (to average the dominant annual gravity signal
   from hydrology present in the monthly GRACE-only fields).

8) Due to missing accelerometer data on both satellites in the second half of
   November 2011, the model

   GSM-2_2011289-2011320_0031_EIGEN_G---_0004 Nov 2011

   was derived with data from the period 16 October 2011 till 16 November 2011.

   Due to  missing accelerometer data on both satellites in the first half of
   December 2011, the model

   GSM-2_2011346-2012011_0028_EIGEN_G---_0004 Dez 2011

   was derived with data from the period 12 December 2011 till 11 January 2012.