Leica apMK12, Operation & Installation Manual

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Version 1.5 187
Glossary Operation & Installation Manual
DILUTION OF PRECISION (DOP)
A figure of merit for the quality of GPS-derived position and clock
bias estimates, based on the geometry of the selected satellite con-
stellation. The smaller the DOP, the less the magnification of the
range measurement error into position and clock bias errors. Gen-
erally, 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.
E ARTH 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.
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