The geodetic latitude of the observer


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" .



All Frames have this attribute.
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.
Together with the ObsLon attribute, it is used when converting between certain time scales (TDB, TCB, LMST, LAST)