UM513
Subroutine UM513  set the DGRF/IGRF model coefficients
REAL*8 tm
CHARACTER*32 lbl
CALL UM513 (tm, lbl)

tm

Epoch of the geomagnetic field calculation expressed in year [in]

lbl

Label of the geomagnetic field model [out]
The subroutine UM513 initializes the expansion coefficients of
the geomagnetic field inside the common block UC140
with the coefficients of the DGRF/IGRF model.
The tm
arguments specifies the epoch to which the model
has to be extrapolated. The base epochs of the model are the year
multiple of 5 between 1945 and 1995. The expansion coefficients are
extrapolated from the nearst base epoch that precedes the tm
time.
As result, the lbl
argument contains a string with the
name of the model.
History
In version 1.11 and earlier, the description of the IGRF/DGRF 4595
geomagnetic field models were included in a specific block data
(DGRFBD).
Since some Fortran compilers (e.g. Microsoft PowerStation) are not
able to link correctly such block data, the DATA statements have been
included in the subroutine UM533.
Note that the common block
DGRF
is not more present in the UNILIB library.
UC140,
magnetic field description
Called by
UM510,
select a geomagnetic field model
Calls
UM515,
perform a Schmidt normalisation
UM511,
set the Jensen & Cain 1960 model coefficients
UM512,
set the GSFC 12/66 model coefficients