ARMY TM 5-6675-308-12
MARINE CORPS TM 08837A-12/1A
Section I. Definitions OF SPECIAL TERMS
L
A
LOCAL VERTICAL - Coincident with gravity vertical.
ACCELEROMETER - A device which measures
acceleration. The output is double integrated to deter-
M
mine change in distance.
MARK - The process of establishing the horizontal
AZIMUTH -Horizontal angle measured clockwise from
position and elevation of a point and/or azimuth of an
true north (true azimuth), or from grid north (grid
orienting line using plumb bob or theodolite.
azimuth), to a line through an observed or designated
point.
MIL - A unit of angular measurement equal to 1/6400
of 360, or approximately 003.4' of arc approximately
AUTOREFLECTION -A method of creating a perpen-
equal to 1/1000 of the range.
dicular line by projecting an image of a theodolite sight
to a reflecting porro prism, then back to the telescope.
N
B
NORTHING - The north-south position (UTM grid).
BIT - Built-in test; normally, a test for proper
O
functioning.
ORIENTING LINE - Line of known direction material-
BITE - Built-in test equipment; components within an
ized on the ground.
equipment which are used to conduct built-in tests.
P
E
PORRO PRISM - A prism which has two reflecting
EASTING - The east-west position (UTM grid).
surfaces at right angles to each other.
F
S
FAULT INDICATOR - An indicator which allows an
SPHEROID - An earth spheroid model used for com-
observer to see that the system concerned is functioning
puting geodetic positions. Different models are used in
properly (black color), or malfunctioning (white color).
various parts of the world. PADS can accommodate:
G
Clarke 1866
International
GYROSCOPE - A spinning wheel which tends to keep
Clarke 1880
a fixed orientation in space. Used to sense rotation.
Everest
Bessel
GYROCOMPASSING - A method used to find true
Australian GRS 67
north by sensing earth rotation.
GRS 1980 WGS 84
Airy
Modified Airy
H
Modified Everest
WGS 72
HUB - A temporary traverse-station marker, usually of
Hough
wood. The stake is driven flush with the ground with
a tack or small nail on top to mark the exact point of
reference for angular and linear measurements.
Glossary 1
Change 3
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