Leica MX400 Operating Instructions Manual page 213

Operator's Manual
A figure of merit for the quality of GPS-derived position and
clock bias estimates, based on the geometry of the selected
satellite constellation. The smaller the DOP, the less the
magnification of the range measurement error into position and
clock bias errors. Generally, the more spread out the satellites,
the lower the DOP. The most common DOPs are as follows:
HDOP - Horizontal dilution of precision.
GDOP - Geometric dilution of precision.
PDOP - Position dilution of precision.
VDOP - Vertical dilution of precision.
EARTH FLATTENING COEFFICIENT
See COEFFICIENT OF EARTH FLATTENING.
EDIT
To modify existing display data via the keyboard.
EDIT MODE
The state in the navigator where it is possible to enter or change
data. EDIT MODE is accessed by pressing the E-key. Press the
E-key once more to ENTER the data into the memory and leave
EDIT MODE.
ELEVATION ANGLE
The angle made by the line-of-sight range to the satellite and the
horizontal plane of the navigator antenna. Thus, the elevation
angle is 90 degrees when the satellite is overhead and 0
degrees when it first appears on the horizon. Satellites whose
maximum elevation angle is less than 5 degrees are not good
candidates for providing an accurate position (latitude and
longitude) update.
ELLIPSOID
A spheroid whose north-south axis is shorter than the east-west
axis (oblate spheroid).
ENTER
To store data in the memory of the navigator.
EPHEMERIDES (Singular: EPHEMERIS)
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Glossary
Version 3.3