/
shread2error.doc
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/
shread2error.doc
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Read spherical harmonic coefficients from a CHAMP or GRACE-like ascii-formatted
file.
Usage
-----
cilm, error, lmax, gm, r0_pot, dot, doystart, doyend, epoch = SHRead2Error
(filename, lmaxin)
Returns
-------
cilm : float, dimension (2, lmaxin+1, lmaxin+1)
The spherical harmonic coefficients contained in filename.
error : float, dimension (2, lmaxin+1, lmaxin+1)
The uncertainty of the spherical harmonic coefficients contained in
filename.
lmax : integer
The maximum spherical harmonic degree of cilm. This is the minimum of the
dimension of cilm and lmaxin.
gm : float
The mass-gravitational constant.
r0_pot : float
The reference radius of the potential coefficients.
dot : float, dimension (2, lmaxin+1, lmaxin+1)
The time derivatives of the spherical harmonic coefficients. The dimension
of this array can be smaller than lmax+1.
doystart : float
The starting time of the solution.
doyend : float
The ending time of the solution
epoch : float
The epoch time for the time derivates.
Parameters
----------
filename : character(*)
The ascii-formatted filename containing the spherical harmonic coefficients.
lmaxin : integer
This spherical harmonic degree controls the dimension of the output array
cilm. The coefficients between lmax+1 and lmaxin will be set to zero.
Description
-----------
SHRead2Error will read spherical harmonic coefficients from a CHAMP or GRACE-
like ascii-formatted file into an array cilm. The errors and time derivatives
associated with the coefficients will be read if the optional arrays error and
dot are specified, respectively. The staring and ending date of the solution are
specified by the optional parameters doystart and doyend, and the epoch of the
time derivates is specified by the optional parameter epoch. The maximum
spherical harmonic degree is read from the file, and the file does not need to
be ordered by angular degree or order.
This routine does not read and output all parameters in the file. Records that
are read (and at least partially output) include: EARTH, GGM, SHM, GRCOF2,
GRDOTA, CALSDV, gfc, gfct, and dot. Comments specified by the record CMMNT will
be print out to the screen, as will the record names that are not currently
implemented.
Each line of the file starts with a character string describing what follows.
- EARTH or GGM: GM, R0_POT
- SHM: Maximum spherical harmonic degree of file.
- GRCOF2, CALSDV, or gfc: spherical harmonic coefficients, formatted as (l, m,
clm, slm) or (l, m, clm, slm, clm_error, slm_error).