The gravity field model ITSG-Grace2014
======================================
T. Mayer-Guerr, N. Zehentner, B. Klinger, A. Kvas
http://itsg.tugraz.at/research/ITSG-Grace2014

ITSG-Grace2014k variance-covariance matrix
==========================================
In the adjustment process of the ITSG-Grace2014s gravity field model a total of 40397 spherical
harmonic coefficients of the static gravity field were estimated.
The upper triangle of their covariance matrix is partitioned into blocks of size 2048x2048 in the
following way:

    ------------------------------------------------------------
    | *.00-00 | *.00-01 | *.00-02  | *.00-03 |  ...  | *.00-19 |
    |         | *.01-01 | *.01-02  | *.01-03 |  ...  | *.01-19 |
    |         |         | *.02-02  | *.02-03 |  ...  | *.02-19 |
    |         |         |          | *.03-03 |  ...  | *.03-19 |
    |         |         |          |         |  ...  |   ...   |
    |         |         |          |         |       | *.19-19 |
    ------------------------------------------------------------

Each block is stored as ASCII-File using the file format described in detail in
the next chapter.

Matrix Block Format Description
===============================

Line 0:       file format descriptor
Line 1:       <matrix type>( <nrows> x <ncolumns> )
              Type and size of stored matrix

              Values of <matrix type>:

              - Matrix (general rectangular matrix)
              - UpperSymmetricMatrix (upper triangle of symmetric matrix)

Line 2 - Line 2+nrows:

              Matrix elements as whitespace separated floating point values.

              Type Matrix  storage format:
              -------------------------------------------
              | a_00 | a_01 | a_02 | a_03 | a_04 | a_05 |
              -------------------------------------------
              | a_11 | a_11 | a_12 | a_13 | a_14 | a_15 |
              -------------------------------------------
              | a_22 | a_21 | a_22 | a_23 | a_24 | a_25 |
              -------------------------------------------
              | a_33 | a_31 | a_32 | a_33 | a_34 | a_35 |
              -------------------------------------------

              Type UpperSymmetrixMatrix storage format (only upper triangle is stored):
              -------------------------------------------
              | a_00 | a_01 | a_02 | a_03 | a_04 | a_05 |
              -------------------------------------------
              |      | a_11 | a_12 | a_13 | a_14 | a_15 |
              -------------------------------------------
              |      |      | a_22 | a_23 | a_24 | a_25 |
              -------------------------------------------
              |      |      |      | a_33 | a_34 | a_35 |
              -------------------------------------------
              |      |      |      |      | a_44 | a_45 |
              -------------------------------------------
              |      |      |      |      |      | a_55 |
              -------------------------------------------


Spherical Harmonic Coefficient Order
====================================

The spherical harmonic coefficient order can be found in the file
coefficient_list_static.txt.