----+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
ATGRAV
----+----0----+----0----+----0----+----0----+----0----+----0----+----0----+----0
COLUMNS FORMAT DESCRIPTION DEFAULT VALUE & UNITS
1-6 A6 ATGRAV - Requests application of
atmospheric effect on the gravity
field. The presence of this card
requests input data on Unit 18 in
GEODYN IIS. [1] The data are times and
coefficients describing the atmospheric
models.
7-8 I2 Maximum degree of expansion. [2] 50
9-10 I2 Maximum order of expansion. [2] 50
11-12 I2 Indicator for linear interpolation 0
=0 Do not perform linear interpolation
for the atmospheric coefficients. Apply
the given values if time of observation
falls six hours before or after the time
where the coefficients were computed.
=1 Perform linear interpolation. Use the pair
of atmospheric coefficient sets that preceed
and follow the observation time. For
observations that fall before the first
and after the last set perform linear
extrapolation
25-44 D20.8 YYMMDDHHMMSS.SS Start time of
application epoch start
time
45-59 D15.3 YYMDDHHMMSS.SS End time of
application epoch stop
time
APRIL 1994
9404.0
GLOBAL SET
ATGRAV (cont)
NOTE [1]: GEODYN IIS unit 18 is a binary file which contains in each record.
(a) The time in the middle of the 12 hour period where the
following coefficients apply and
(b) a stream of 50x50 coefficients in the following sequence
C00
C10
C11
S11
C20
C21
S21
C22
S22
C30
C31
S31
C32
S32
C33
S33
NOTE [2] : The expansion should be less than or equal to the
gravity field expansion. If not, only the coefficients
of degree and order less than the maximum degree and
order of the gravity field will contribute.
GEODYN will accept up to 50x50 expansions for this option
given at 12 hour intervals.
IF CARD OMITTED: Atmospheric effect will not contribute to the
gravity coefficients.
JUL 1998
9808.0
GLOBAL SET