This
attribute specifies the geodetic latitude of the observer, in degrees, relative
to the IAU 1976 reference ellipsoid. The basic
Frame class makes no use of
this attribute, but specialised subclasses of Frame may use it. For instance,
the
SpecFrame,
SkyFrame and
TimeFrame classes use it. The default value is
zero.
The value is stored internally in radians, but is converted to and from a degrees
string for access. Some example input formats are: "
22:19:23.2"
, "
22 19 23.2"
, "
22:19.387"
, "
22.32311"
, "
N22.32311"
, "
-45.6"
, "
S45.6"
. As indicated, the sign of
the latitude can optionally be indicated using characters "
N"
and "
S"
in place of the
usual "
"
and "
-"
. When converting the stored value to a string, the format "
[s]dd:mm:ss.ss"
is used, when "
[s]"
is "
N"
or "
S"
.
Frame
All
Frames have this attribute.
SpecFrame
Together with the
ObsLon,
Epoch,
RefRA and
RefDec attributes, it defines the Doppler shift introduced by the observers diurnal
motion around the earths axis, which is needed when converting to or from the
topocentric standard of rest. The maximum velocity error which can be caused by an
incorrect value is 0.5 km/s. The default value for the attribute is zero.
TimeFrame
Together with the ObsLon attribute, it is used when converting between certain time
scales (TDB, TCB, LMST, LAST)