 |
perspective
to |
| � |
angle(s) |
| � |
degree(s) |
| a |
azimuth
of line |
| a |
angle |
| k |
correction
for the earth's curvature |
| � |
sum |
| ' |
minute(s) |
| " |
second(s) |
 |
delta |
| E |
delta easting |
| N |
delta northing |
| f |
latitude |
| F |
phi |
| h1 |
elevation
of the occupied station |
| l |
longitude |
| q |
Theta |
| r |
symbol for
rho - radius of curvature |
| s |
grid distance |
| s |
sigma |
| t |
tau |
| z |
mean observed
zenith distance |
| 1D |
one dimensional |
| 1DRMS |
1-deviation
root-mean-square |
| 1LT |
first lieutenant |
| 1SG |
first sergeant |
| 2D |
two dimensional |
| 2DRMS |
2-deviation
root-mean-square |
| 3D |
three dimensional |
| 3DRMS |
3-deviation
root-mean-square |
| A/M |
angle measure |
| AAF |
Army airfield |
| AAL |
additional
authorizations list |
| AC |
alternating
current |
| accuracy |
the degree
of conformity with a standard or the degree of perfection attained in a
measurement; accuracy relates to the quality of a result and is distinguished
from precision, which relates to the quality of the operation used to obtain
the result |
| actual
error |
the difference
between the accepted value and the measured value of a physical quantity |
| ADA |
air-defense
artillery |
| adj |
adjusted |
| adjust |
adjustment |
| adjusted
position |
an adjusted
value for the horizontal or vertical position of a survey station, in which
discrepancies due to errors in the observed data are removed, that forms
a coordinated and correlated system of stations |
| AE |
allowable
error |
| AEC |
angular
error of closure |
| aeronautical
beacon |
a visual
NAVAID displaying flashes of white and/or colored light to indicate the
location of an airport, a heliport, a landmark, a certain point of a federal
airway in mountainous terrain, or an obstruction |
| AG |
Adjutant
General |
| AH |
ampere-hour |
| air-navigation
facility |
any facility
used in, available for use in, or designed for use in the aid of air navigation
(this includes landing areas; lights; any apparatus or equipment used for
disseminating weather information, signaling, radio-directional finding,
or radio or other electrical communication; and any other structure or mechanism
having a similar purpose of guiding or controlling the flight, the landing,
or the takeoff of aircraft) |
| airport
elevation |
the highest
point of an airport's usable runways measured in feet from the MSL |
| airport
lighting |
various
lighting aids installed on airports. These aids can include
1) airport rotating beacons�a visual NAVAID that is operated at many
airports. At civil airports, alternate white and green flashes indicate
the location of the airport. At military airfields, the beacon is differentiated
by dual peak (two quick) white flashes between the green flashes;
2) approach-light
systems (ALSs)�an airport lighting facility which provides visual
guidance to landing aircraft by radiating light beams in a directional
pattern by which the pilot aligns the aircraft with the extended runway
centerline on his final approach for landing. A number of ALS configurations
exist, both with and without sequenced flashing lights. One system, the
omnidirectional ALS (ODALS), consists of seven omnidirectional flashing
lights located in the approach area of a nonprecision approach. Five of
the lights are located on the extended runway centerline and the other
two lights are located one on each side of the runway threshold;
3) REILs�two
synchronized flashing lights, one on each side of the runway threshold,
provide rapid and positive identification of the approach end of a runway;
4) visual-approach
slope indicators (VASI)�an airport lighting facility providing vertical
visual-approach slope guidance to aircraft during the approach for landing
by radiating a directional pattern of high-intensity, red and white, focused
light beams, which indicate to the pilot if he is above, below, or on
the glide path. The term VASI also has a generic connotation for a tricolor-approach
slope indicator consisting of a single light unit projecting a three-color,
visual-approach path into the final approach area of the runway served
by the system;
5) pulse-light
approach-slope indicators (PLASI)�a VASI, normally consisting of a
single light unit projecting a pulsating two-color, visual-approach path
into the final approach area of the runway served by the system; and
6) precision approach-path
indicators (PAPI)�a VASI, consisting of a single row of two or four
light units, usually installed on the left side of the runway served by
the system
|
| airport
reference point |
the position
of the approximate center of mass of all usable runways. This point is not
strictly the center of mass of runways, since the runway width, thickness,
or material is not considered in the computation. An ARP is not monumented;
therefore, it is not recoverable on the ground |
| airport
surveillance radar |
approach
control radar that is used to detect and display an aircraft's position
in the terminal area. The ASR provides range and azimuth information but
does not provide elevation data (coverage of the ASR can extend up to 60
nautical miles) |
| air-route
surveillance radar |
air-route
traffic control center (ARTCC) radar used primarily to detect and display
an aircraft's position while en route between terminal areas (coverage of
the ARSR can extend up to 200 nautical miles) |
| AISI |
automated
integrated survey instrument |
| ALP |
airport
location point |
| ALS |
approach-light
system |
| altimeter |
an aneroid
barometer that is used for the measurement of approximate elevations or
approximate differences of elevation |
| altitude |
the vertical
angle that is measured between the plane of the observer's true horizon
and a line to the object |
| ambiguity
resolution |
with carrier-phase
observations, the number of carrier-phase cycles between the receiver and
the satellite is generally unknown and is referred to as the ambiguity and
is an integer number. Single and double differences are also affected by
ambiguities, which are formed by a linear combination of carrier-phase integer
ambiguities (for example, a single or double differenced ambiguity). Where
the integer ambiguities are unknown, they may be estimated by processing
software. In some cases, these real-valued estimates may be used to determine
the correct integer values, which are then held fixed. A float solution
is derived when the real-valued estimates are used, rather than the
integers |
| ang |
angle |
| ant |
antenna |
| AO |
area of
operation |
| AOC |
airport
obstruction chart |
| AP |
airport
plan |
| APFT |
Army physical
fitness test |
| approx |
approximate |
| Apr |
April |
| apron |
a defined
area on an airport or heliport intended to accommodate aircraft for purposes
of loading and unloading passengers or cargo, refueling, parking, or maintenance
(seaplanes use a ramp for access from the water to the apron) |
| AR |
Army regulation |
| ARP |
airport
reference point |
| ARSR |
air-route
surveillance radar |
| ARTCC |
air-route
traffic control center |
| ARTEP |
Army Training
and Evaluation Program |
| AS |
antispoofing |
| ASCII |
American
Standard Code for Information Interchange |
| ASPRS |
American
Society of Photogrammetry and Remote Sensing |
| ASR |
airport
surveillance radar |
| astronomical
latitude |
the angle
between the plumb line and the plane of the celestial equator; also defined
as the angle between the plane of the horizon and the axis of rotation of
the earth. Astronomical latitude applies only to positions on the earth
and is reckoned from the astronomic equator (0�), north and south through
90�. Astronomical latitude results directly from observations of celestial
bodies, which are uncorrected for deflection of the vertical |
| astronomical
longitude |
the angle
between the plane of the celestial meridian and the plane of an initial
meridian that is arbitrarily chosen. Astronomical longitude results directly
from observations on celestial bodies, uncorrected for deflection of the
vertical |
| ATC |
air traffic
control |
| Aug |
August |
| az |
azimuth |
| azimuth |
the direction
of one object from another, usually expressed as an angle in degrees relative
to true north (azimuths are usually measured in the clockwise direction,
thus an azimuth of 90� indicates that the second object is due east of the
first) |
| azimuth
mark |
the azimuth
to a marked point or adjacent station that is visible from an occupied station,
which is determined for use in dependent surveys |
| b |
backward |
| backsight |
in traversing,
a backsight is a sight on a previously established traverse or triangulation
station, which is not the closing sight on the traverse; in leveling, a
backsight is a reading on a rod that is held on a point whose elevation
has been previously determined and is not the closing sight of a level line |
| BAQ |
basic allowance
for quarters |
| base
network |
a small
network of geometric figures that is used to expand from a baseline to a
line of the main scheme of a triangulation network |
| baseline |
a surveyed
line that is established with more than usual care, to which surveys are
referred for coordination and correlation; in GPS baseline reduction, geodetic
parameters are estimated at one station relative to another, with the receivers
at both sites observing common satellites simultaneously |
| basic
control |
horizontal
and vertical control of third- or higher-order accuracy (determined in the
field and permanently marked or monumented) that is required to control
further surveys |
| BC |
basic control |
| BCM |
basic-control
marker |
| bearing |
the direction
of one object from another, usually expressed as an angle in degrees relative
to a specific primary direction (bearings differ from azimuths in that bearing
values do not exceed 90�) |
| benchmark |
a relatively
permanent object, natural or artificial, bearing a marked point whose elevation
above or below an adopted datum is known; usually designated as a BM, such
a mark is sometimes further qualified as a PBM or as a temporary BM (TBM) |
| BEQ |
bachelor
enlisted quarters |
| bde |
brigade |
| BDE |
backward
difference in elevation |
| BII |
basic issue
items |
| blast
pad |
a specially
prepared surface that is placed adjacent to the ends of runways to eliminate
the erosive effect of the high wind forces produced by airplanes at the
beginning of their takeoff rolls |
| BM |
benchmark |
| bn |
battalion |
| broadcast
ephemeris |
the predicted
satellite position in its orbit as a function of time computed from the
ephemeris parameters contained in the navigation message broadcast on both
the L1 and L2 carrier waves |
| bs |
backsight |
| btry |
battery |
| C2 |
command
and control |
| C |
Celsius |
| C/A-code |
coarse-acquisition
code |
| CAD |
computer-aided
design |
| cadastral
survey |
a survey
relating to land boundaries and subdivisions, which is made to create units
suitable for the transfer of or to define the limitations of a title; surveys
of the public lands of the US, including retracement surveys for the identification
of and resurveys for the restoration of property lines; and for corresponding
surveys outside the public lands, although such surveys are usually termed
land surveys |
| CADD |
computer-aided
design and drafting |
| carrier
phase |
the phase
(as measured at the antenna phase center of a GPS receiver) of two sinusoidal
radio signals (the two carriers) that are continuously emitted by each GPS
satellite |
| C-check |
collimation
test for leveling |
| CDC |
consecutive
Doppler counts |
| celestial
equator |
a great
circle on the celestial sphere on which any point is equidistant from the
celestial poles (the plane of the earth's equator, if extended, would coincide
with that of the celestial equator) |
| celestial
meridian |
a vertical
circle (the plane of which is perpendicular to the celestial equator) passing
through both celestial poles |
| celestial
pole |
a reference
point located at the point of intersection of an indefinite extension of
the earth's axis of rotation and the apparent celestial sphere |
| celestial
sphere |
an imaginary
sphere of infinite radius, with the earth as the center, that rotates from
east to west on a prolongation of the earth's axis |
| central
meridian |
the longitude
of the horizontal center of a coordinate system (this longitude value is
often the longitude origin of the coordinate system); in the case of the
transverse Mercator projection, the CM is the great circle/geodesic at which
the projection surface (the cylinder) touches or is tangent to the earth |
| CEOI |
communications-electronics
operation instructions |
| CEP |
circular
error probable |
| CESI |
communications-electronics
standing instruction |
| C-factor |
collimation
error; error of the sighting of the level |
| chron |
chronometer |
| chronometer |
a portable
timekeeper with compensated balance, which is capable of showing time with
extreme precision and accuracy |
| CID |
continuously
integrated Doppler |
| circle
position |
a prescribed
setting (reading) of the horizontal circle of a direction theodolite, which
is used for observing the initial station of a series of stations |
| circuit
closure |
in leveling,
it is the amount by which the algebraic sum of the measured differences
of elevation around a circuit fails to equal zero |
| circumpolar
star |
a star in
any given latitude that never goes below the horizon; hence, its polar distance
must be less than the given latitude; in astronomy, only those stars with
a polar distance of less than 10� are considered in practical problems |
| cl |
closure |
| C/L |
centerline |
| clearway |
an area
beyond the takeoff runway that is under the control of airport authorities
where terrain or fixed obstacles may not extend above specified limits (these
areas may be required for turbine-powered operations and the size and upward
slope of the clearway will differ depending on when the aircraft was certified)
|
| cm |
centimeter(s) |
| CM |
central
meridian |
| COEI |
components
of end item |
| collimation |
the line
of sight or aiming line of an instrument when coincident with the physical
alignment of the instrument; thus, a collimation error is the angle between
the line of collimation (line of sight) of a telescope and the collimation
axis of the instrument |
| comm |
communication |
| comp |
computer |
| compass
locator |
a low-power,
low- or medium-frequency (L/MF) NDB that is installed at the site of the
outer or middle marker (MM) of an ILS (it can be used for navigation at
distances of about 15 miles or as authorized in the approach procedure)
|
| control |
the coordinated
and correlated dimensional data, which are used in geodesy and cartography
to determine the positions and elevations of points on the earth's surface
or on a cartographic representation of that surface; a collective term for
a system of marks or objects on the earth or on a map or a photograph whose
positions or elevations, or both, have been or will be determined |
| control
survey |
a survey
that provides positions (horizontal or vertical) of points to which supplementary
surveys are adjusted |
| CONUS |
continental
United States |
| coordinate
system |
an exact
definition of a system of mathematics and geodetic constants that defines
how a specific geographic location is converted to a set of two or three
numbers (for example, an X- and Y-value [and possibly a Z-value]); in the
cartographic context, most coordinate systems are Cartesian (the axes are
orthogonal [perpendicular to each other]) and the units are the same on
all axes; the principle exception to this is the spherical coordinate system
of latitudes and longitudes |
| coordinates |
linear and/or
angular quantities, which designate the position of a point in relation
to a given reference frame; there are two general divisions of coordinates
used in surveying�polar and rectangular; these may be further subdivided
into three classes�plane coordinates, spherical coordinates, and space coordinates
|
| coords |
coordinates |
| Corps
Conversion |
a software
program that converts horizontal coordinates to and from geographic, state-plane,
and UTM systems on the NAD 27 and the NAD 83 and converts vertical coordinates
on the NGVD 29 and the NAVD 88 |
| Corpscon |
Corps Conversion |
| corr |
correction |
| CORS |
continuously
operating reference station |
| cos |
cosine |
| CPT |
captain |
| C&R |
curvature
and refraction |
| CTT |
common training
task |
| cycle
slips |
cycle slips
occur when there are breaks in the continuity of signal in a satellite-receiver
pair. Data sampling requires the choosing of the sampling rate and the starting
and finishing epochs for the observations. Data editing is required for
cycle slips and for data sampling |
| D |
ratio of
side/sine |
| DA |
Department
of the Army |
| datum |
the combination
of an ellipsoid, that specifies the size and shape of the earth, and a base
point from which the latitude and longitude of all other points are referenced.
Before satellites, lasers, and computers, establishing precise values for
these points was impossible. More recently, many datums have been established
and substantial amounts of data collected based on each. Data based on one
datum will not necessarily overlay data based on another datum. A geodetic
datum is a reference surface consisting of five quantities: the latitude
and longitude of an initial point, the azimuth and distance of a line from
this point, and the parameters of the reference ellipsoid. It forms the
basis for the computation of horizontal-control surveys in which the curvature
of the earth is considered. A leveling datum is a level surface to which
elevations are referred (usually, but not always, the MSL) |
| DD |
Department
of Defense |
| dE |
difference
in easting |
| DE |
difference
in elevation |
| declination |
in a system
of polar or spherical coordinates, the angle at the origin between a line
to a point and the equatorial plane, measured in a plane perpendicular to
the equatorial plane; the arc between the equator and the point measured
on a great circle, which is perpendicular to the equator; as it relates
to astronomy, the angular distance to a body on the celestial sphere that
is measured north or south through 90� from the celestial equator along
the hour circle of the body. Comparable to latitude on the terrestrial sphere
and often used as a shortened term for magnetic declination |
| deflection
of the vertical |
the angular
difference, at any place, between the upward direction of a plumb line (the
vertical) and the perpendicular (the normal) to the reference spheroid.
This difference seldom exceeds 30 seconds and is often expressed in two
components�meridian and prime vertical |
| deg |
degree(s) |
| det |
detachment |
| dev |
deviation |
| DGPS |
differential
global-positioning system |
| dH |
difference
in the horizontal aim |
| diff |
difference |
| differencing |
nondifferencing
(one-way phase) is the measured carrier phase between one satellite and
one receiver. Single differencing (first difference) is the difference between
one-way measurements recorded at two receivers (for example, two receivers
simultaneously observing a common satellite and differencing the recorded
measurements). Double differencing (second difference) is the difference
between two single differences (for example, two stations observing two
satellites, forming differences between the site pair and the satellite
pair). Triple differencing (double difference rate/epoch differences) is
the differencing of double differences between consecutive epochs |
| dir |
direction
|
| direct
leveling |
the determination
of DEs by the means of a continuous series of short horizontal lines. Vertical
distances from these lines to adjacent ground marks are determined by direct
observations on graduated rods with a leveling instrument equipped with
a spirit level |
| direct
reading |
the reading
of the horizontal or vertical circle of a theodolite or engineer transit
with the telescope in the direct position. In field notes, a direct reading
is indicated with a letter D preceding the observed value |
| direction
finder |
a radio
receiver equipped with a directional sensing antenna used to take bearings
on a radio transmitter |
| direction
instrument theodolite |
a theodolite
in which the graduated horizontal circle remains freed during a series of
observations. The telescope is pointed on a number of signals or objects
in succession and the direction of each is read on the circle (usually by
means of micrometer microscopes). Direction instrument theodolites are used
almost exclusively in first- and second-order triangulation |
| dist |
distance |
| distance
angle |
an angle
in a triangle that is opposite the side which is used as a base in the solution
of the triangle or a side whose length is to be computed |
| distance
measuring equipment |
equipment
that is (airborne or ground) used to measure (in nautical miles) the slant-range
distance of an aircraft from the DME NAVAID |
| DIVARTY |
division
artillery |
| DMA |
Defense
Mapping Agency |
| DME |
distance
measuring equipment |
| DMS |
Defense
Mapping School |
| dN |
difference
in northing |
| DOD |
Department
of Defense |
| DOP |
dilution
of precision |
| DPW |
Directorate
of Public Works |
| D/R |
direct/reverse |
| DRU |
data recording
unit |
| dsplcd |
displaced |
| DT |
displaced
threshold |
| dV |
difference
in the vertical aim |
| E |
east |
| EAC |
echelons
above corps |
| EC |
error of
closure |
| ECEF |
earth centered
earth fixed |
| ecliptic |
the great
circle of the celestial sphere that is the apparent path of the sun among
the stars or of the earth as seen from the sun. It is inclined to the celestial
equator at an angle of about 23�27' |
| EDM |
electronic
distance measurement |
| EDME |
electronic
distance measuring equipment |
| Ee |
error in
easting |
| elev |
elevation |
| elevation |
the vertical
distance from a datum, usually the MSL, to a point or object on the earth's
surface (not to be confused with altitude, which refers to points or objects
above the earth's surface) |
| ell |
ellipsoidal |
| ellipsoid |
the mathematical
shape that best describes the shape of the earth and yet is relatively simple
to deal with mathematically. Ellipsoids are defined with two numbers. First,
the equatorial radius is specified (also referred to as the semimajor axis).
Second, one of the following three numbers is given, the polar radius (also
known as the semiminor axis), the eccentricity, or the flattening. Given
the equatorial radius and any one of the three secondary values, the remaining
secondary values can be computed. A specific determination of the size of
the earth is often referred to as an ellipsoid. For example, the phrase
"Clarke ellipsoid of 1866" is frequently used to refer to the measurements
of the size of the earth made by Clarke in 1866 |
| ellipsoid
height |
the height
of an object above the reference ellipsoid in use. This term is generally
used to qualify an elevation as being measured from the ellipsoid as opposed
to the geoid. GPS systems calculate ellipsoidal height. The geoid height
at that location must be subtracted to obtain what is commonly referred
to as the elevation |
| elongation |
the point
in the apparent movement of a circumpolar star when the star reaches the
extreme position east or west of the meridian |
| EM |
engineer
manual |
| en |
engineer |
| En |
error in
northing |
| eng |
engineer |
| engr |
engineer |
| EOR |
end of runway |
| ephemeris
time |
a uniform
measure of time that is defined by the laws of dynamics and determined in
principle from the orbital motions of the planets, specifically in the orbital
motion of the earth |
| equation
of time |
the algebraic
difference in hour angle between apparent solar time and mean solar time
(usually labeled plus or minus), as it is to be applied to mean solar time
to obtain apparent solar time |
| equinox |
one of the
two points of intersection of the ecliptic and the celestial equator, which
is occupied by the sun when its declination is 0� |
| error |
the difference
between an observed and true value; a class of small inaccuracies due to
imperfections in equipment or techniques, surrounding conditions, or human
limitations; not to be confused with blunders or mistakes |
| error
of closure |
the amount
by which a quantity obtained by a series of related measurements differs
from the true or fixed value of the same quantity. These include errors
of closure for the following:
Angle. The
amount by which the actual sum of a series of angles fails to equal the
theoretically exact value of that sum.
Azimuth. The
amount by which two values of the azimuth of a line, derived by different
surveys or along different routes, fail to be exactly equal to each other.
Horizon. The
amount by which the sum of a series of adjacent measured horizontal angles
around a point fails to equal exactly 360�. Measurement of the last angle
of the series is called closing the horizon (sometimes called closure
of horizon).
Leveling.
The amount by which two values of the elevation of the same BM, derived
by different surveys or through different survey routes or by independent
observations, fail to be exactly equal to each other.
Loop. The
error in the closure of a survey on itself.
Triangle.
The amount by which the sum of the three observed angles of a triangle
fails to equal exactly 180� plus the spherical excess of the triangle.
Traverse. The
amount by which a value of the position of a traverse station, as obtained
by computation through a traverse, fails to agree with another value of
the same station as determined by a different set of observations or routes
of survey
|
| esc |
escape |
| f |
forward |
| F |
Fahrenheit |
| FA |
field artillery |
| FAA |
Federal
Aviation Administration |
| FAA
405 |
Federal
Aviation Administration Publication 405 |
| FAO |
finance
and accounting office |
| FAR |
Federal
Aviation Regulation |
| FAR-77 |
Federal
Aviation Regulation, Part 77 |
| FDE |
forward
difference in elevation |
| Feb |
February |
| FEBA |
forward
edge of the battle area |
| FED |
Facilities
Engineering Division |
| FGCC |
Federal
Geodetic Control Committee |
| FGCS |
Federal
Geodetic Control Subcommittee |
| final-approach
course |
a straight-line
extension of a localizer, a final approach radial/bearing, or a runway centerline,
all without regard to distance |
| fixed
elevation |
an elevation
that has been adopted (either as a result of tide observations or previous
adjustment of spirit leveling) and is held at its accepted value in any
subsequent adjustment |
| FM |
field manual |
| FM |
frequency
modulated |
| FO |
forward
observer |
| foresight |
an observation
of the distance and direction to the next instrument station. In traversing,
a foresite is a point set ahead to be used for reference when resetting
the transit or line or when verifying the alignment. In leveling, a foresite
is the reading on a rod that is held at a point whose elevation is to be
determined |
| FOUO |
for official
use only |
| FRAGO |
fragmentary
order |
| frequency |
the number
of complete cycles per second existing in any form of wave motion |
| FRNP |
Federal
Radio Navigation Plan |
| fs |
foresight |
| FS |
fire support |
| FSCOORD |
fire-support
coordinator |
| ft |
feet, foot |
| G2 |
Assistant
Chief of Staff, G2 (Intelligence) |
| G3 |
Assistant
Chief of Staff, G3 (Operations and Plans) |
| GCA |
ground-controlled
approach |
| GDOP |
geometric
dilution of precision |
| geod |
geodetic |
| geodesy |
a branch
of applied mathematics concerned with the determination of the size and
shape of the earth (geoid). Direct measurements (triangulation, leveling,
and gravimetric observations) determine the exact location of points on
the earth's surface and its external gravitational field |
| geodetic
control |
a system
of horizontal and/or vertical control stations that have been established
and adjusted by geodetic methods and in which the shape and size of the
earth (geoid) have been considered in position computations |
| geodetic
latitude |
the angle
at which the normal (at a point on the reference spheroid) forms with the
plane of the geodetic equator. Geodetic latitudes are reckoned from the
equator, but in the horizontal-control survey of the US, they are computed
from the latitude of station Meades Ranch as prescribed in NAD 27 |
| geodetic
leveling |
spirit leveling
of a high order of accuracy, usually extended over large areas, to furnish
accurate vertical control as a basis for the control in the vertical dimension
for all surveying and mapping operations |
| geodetic
longitude |
the angle
between the plane of the geodetic meridian and the plane of an initial meridian.
A geodetic longitude can be measured by the angle at the pole of rotation
of the reference spheroid between the local and initial meridians or by
the arc of the geodetic equator intercepted by those meridians. In the US,
geodetic longitudes are numbered from the meridian of Greenwich, but are
computed from the meridian of station Meades Ranch as prescribed in NAD
27. A geodetic longitude differs from the corresponding astronomical longitude
by the amount of the prime vertical component of the local deflection of
the vertical divided by the cosine of the latitude |
| geodetic
reference system |
the technical
name for a datum. The combination of an ellipsoid, which specifies the size
and shape of the earth, and a base point from which the latitude and longitude
of all other points are referenced |
| geodetic
survey |
a survey
of a large land area in which corrections are made for the curvature of
the earth's surface |
| geographic
coordinates |
an inclusive
term that is generally used to designate both geodetic and astronomical
coordinates |
| geoid |
the surface
within or around the earth that is everywhere normal to the direction of
gravity and coincides with MSL in the oceans |
| GEOID93 |
Geoid reference
model 1993 |
| GEOID96 |
Geoid reference
model 1996 |
| GEOID99 |
Geoid reference
model 1999 |
| geoid
height |
the height
of the geoid above the ellipsoid in use (this usually refers to the height
of the geoid above the WGS-84 ellipsoid upon which GPS is based) |
| GEOREF |
geographic
reference |
| GIS |
geographic
information system |
| global
positioning system |
a system
(developed by the US military) based on satellites and sophisticated receivers
that are capable of accurately measuring the geodetic location of a receiver
at any place in the world and is widely used in surveying and navigational
situations |
| GPS |
global positioning
system |
| GPS-S |
global positioning
system-survey |
| gravimeter |
a weighing
device or instrument of sufficient sensitivity that is used to register
variations in the weight of a constant mass when the mass is moved from
place to place on the earth and thereby is subjected to the influence of
gravity at those places |
| gravitation |
the acceleration
produced by the mutual attraction of two masses, directed along the line
joining their centers of mass, and of magnitude inversely proportional to
the square of the distance between the two centers of mass |
| gravity |
viewed from
a frame of reference freed in the earth (acceleration imparted by the earth
to a mass), which is rotating the earth. Since the earth is rotating, the
acceleration observed as gravity is the resultant of the acceleration of
gravitation and the centrifugal acceleration arising from this rotation
and the use of an earthbound rotating frame of reference. |
| ground-controlled
approach |
a radar
approach system operated from the ground by ATC personnel transmitting instructions
to the pilot by radio (the approach may be conducted with ASR and/or PAR) |
| GRS |
geodetic
reference system |
| GRS
80 |
Geodetic
Reference System of 1980 |
| GS |
general
support |
| GSI |
glide-slope
indicator |
| GSR |
ground-surveillance
radar |
| GySgt |
gunnery
sergeant |
| h |
ellipsoidal
height |
| h |
hour(s) |
| H |
orthometric
height |
| HARN |
high-accuracy
reference network |
| H
Dist |
horizontal
distance |
| HDOP |
horizontal
dilution of precision |
| height
of instrument |
in spirit
leveling, it is the height of the line of sight of a leveling instrument
above the adopted datum. In stadia surveying, it is the height of the center
of the telescope (horizontal axis) of the transit or telescopic alidade
above the ground or station mark. In trigonometric leveling, it is the height
of the center of the theodolite (horizontal axis) above the ground or station
mark |
| Hg |
the symbol
for the element mercury |
| HHB |
headquarters
and headquarters battery |
| HHC |
headquarters
and headquarters company |
| HI |
height of
instrument |
| horizontal
control |
a control
point that determines horizontal positions only, with respect to parallels
and meridians or to other lines of reference |
| horizontal
refraction |
a natural
error in surveying, which is the result of the horizontal bending of light
rays between a target and an observing instrument. This error is usually
caused by the differences in density of the air along the path of the light
rays, resulting from temperature variations |
| HQ |
headquarters |
| ht |
height |
| HT |
height of
the observed target |
| IEW |
intelligence
and electronic warfare |
| IFR |
instrument
flight rules |
| IID |
intermittently
integrated Doppler |
| ILS |
instrument
landing system |
| IM |
inner marker |
| imaginary
surface |
any surface
that is defined in FAR-77,
subpart C. A specified surface is an imaginary surface (other than a supplemental
surface) that is designated by appropriate FAA authorities for defining
obstructions. This surface may or may not be the surface specified in FAR-77
for existing approach minimums. A supplemental surface is an imaginary surface
designated by appropriate FAA authorities. A supplemental surface will normally
lie below a specified surface and is intended to provide additional obstruction
information. An object that penetrates a supplemental surface only is a
supplemental obstruction |
| in |
inch(es) |
| INS |
inertial
navigation system |
| inst |
instrument |
| instr |
instrument |
| instrument
landing system |
a precision
instrument approach system that normally consists of electronic components
and visual aids (for example, localizer, glide slope, outer marker (OM),
MM, and approach lights) |
| instrument
runway |
a runway
equipped with electronic and visual NAVAIDs |
| int |
initials |
| intersection
method |
a method
of determining the horizontal position of a point by observations from two
or more points of known position, thus measuring directions that intersect
at the station being located. A station whose horizontal position is located
by intersection is known as an intersection station |
| ionospheric
correction |
the ionosphere
causes a delay in the propagation of a GPS signal that can be estimated
with 50 percent accuracy using any recognized atmospheric model. On baselines
shorter than 20 kilometers, it is mostly eliminated by relative positioning.
For greater accuracy, it can be mostly eliminated by dual frequency observations
and processing |
| isogonic
chart |
a chart
that features a system of isogonic lines, each for a different value of
the magnetic declination |
| isogonic
line |
a line drawn
on a map or chart joining points of equal magnetic variation |
| ISVT |
initial
site-visitation trip |
| JAG |
Judge Advocate
General |
| Jan |
January |
| K |
a scale
factor used to convert a measured distance to a grid distance |
| K� |
a scale
factor used to reduce a grid distance |
| KE |
correction
to easting |
| km |
kilometer(s) |
| KN |
correction
to northing |
| landing
direction indicator |
a device
that visually indicates the direction in which landings and takeoffs should
be made |
| lat |
latitude |
| latitude |
the north/south
component of the spherical coordinate system most widely used to record
geodetic locations. Originally, when the earth was thought to be spherical,
a degree of latitude represented one degree of arc on the surface of the
earth, which is referenced to the center of the earth. Now that it is known
that the earth is ellipsoidal in shape, there are several types of latitude.
The usual definition of latitude is the angle a line, perpendicular to the
surface of the ellipsoid, forms with the plane of the equator. This is also
referred to as the geographic latitude or geodetic latitude. Whenever the
unqualified term latitude is used, it is generally accepted that it refers
to the geographic latitude. Normal conventions dictate that north latitudes
be given in degrees where positive numbers indicate north latitudes and
negative numbers indicate south latitudes |
| L-band |
frequency
used by SVs to exchange information |
| LEC |
linear error
of closure |
| level
datum |
a level
surface to which elevations are referred. The generally adopted level datum
for leveling in the US is the MSL. For local surveys, an arbitrary level
datum is often adopted and defined in terms of an assumed elevation for
some physical BM |
| level
net |
Lines of
spirit leveling connected together to form a system of loops or circuits
extending over an area |
| line
of sight |
the straight
line between two points (this line is in the direction of a great circle
but does not follow the curvature of the earth); also, the line extending
from an instrument along which distant objects are seen when viewed with
a telescope or another sighting device |
| L/MF |
low or medium
frequency |
| localizer |
the component
of an ILS that provides course guidance to the runway |
| localizer
back course |
the course
line defined by the localizer signal along the extended runway centerline
in the opposite direction to the normal localizer approach course (front
course) |
| localizer-type
directional aid |
a NAVAID
used for nonprecision instrument approaches with utility and accuracy comparable
to a localizer; however, it is not part of a complete ILS and is not aligned
with the runway |
| lon |
longitude |
| long |
longitude |
| longitude |
the east/west
component of the spherical coordinate system most widely used to record
geodetic locations. Lines of longitude are great circles/geodesics, which
pass through the north and south pole, and intersect the equator. All lines
of longitude proceed in a true north/south direction. The imaginary lines
of longitude are assigned values that represent, in degrees of arc, the
distance of the line from the prime meridian (the line of longitude that
passes through Greenwich, England, is the most common prime meridian in
use today) |
| long-range
navigation |
an electronic
navigation system by which hyperbolic LOPs are determined by measuring the
difference in the time of reception of synchronized pulse signals from two
fixed transmitters. The long-range navigation (LORAN) A operates in the
1750- to 1950- kilohertz frequency band. The LORAN C and D operate in the
100- to 110-kilohertz frequency band |
| LOP |
line of
position |
| LORAN |
long-range
navigation |
| LRA |
local reproduction
authorized |
| LTC |
lieutenant
colonel |
| m |
meter(s) |
| m |
minute(s) |
| MACOM |
major Army
command |
| mag |
magnetic |
| main-scheme
station |
a station
through which the basic survey computations are carried, also called a principal
station |
| Mar |
March |
| marker
beacon |
an electronic
NAVAID transmitting a 75-megahertz vertical-fan or bone-shaped radiation
pattern. Marker beacons are identified by their modulation frequency and
keying code and, when received by compatible airborne equipment, indicate
to the pilot (both aurally and visually) that he is passing over the facility.
Marker beacons include the following:
Basic-control marker (BCM). When installed, this normally indicates the
localizer basic-control final-approach fix where approach descent is commenced.
Inner marker (IM). A marker beacon (used with an ILS category-II precision
approach) that is located between the MM and the end of the ILS runway.
It also marks progress during an ILS category-III approach. The IM is usually
located at the point of decision height for ILS category-II approaches.
MM. A marker beacon that defines a point along the glide slope of an ILS,
usually located at or near the point of decision height for ILS category-I
approaches.
OM. A marker beacon that is at or near the glide-slope intercept altitude
of an ILS approach. The OM is normally located 4 to 7 miles from the runway
threshold on the extended centerline of the runway |
| mean
sea level |
the mean
surface-water level that was determined by averaging heights at all stages
of the tide over a 19-year period (often used as a reference for general
leveling operations) |
| meas |
measurement |
| meridian |
in a cartographic/geodetic
context, a meridian is a line of longitude |
| met |
meteorological |
| MET |
missile
escort team |
| MFR |
memorandum
for record |
| MGRS |
military
grid-reference system |
| mi |
mile(s) |
| micro |
micrometer |
| MID
E |
middle easting |
| MID
N |
middle northing |
| mil |
a unit of
angular measurement that is equal to 1/6400 of 360� and used especially
in FA |
| min |
minute(s) |
| minimum |
weather
condition requirements that are established for a particular operation or
type of operation (for example, instrument flight rules (IFR) takeoff or
landing, alternate airport for IFR flight plans, or visual flight rules
(VFR) flight) |
| missed
approach |
a maneuver
that is conducted by a pilot when an instrument approach cannot be completed
to landing |
| MLRS |
multiple-launch
rocket system |
| MLS |
microwave
landing system |
| mm |
millimeter(s) |
| MM |
middle marker |
| mn |
mean |
| mo |
month |
| MOA |
memorandum
of agreement |
| Mon |
Monday |
| monument |
any object
or collection of objects that indicate the position on the ground of a survey
station. In military surveys, the term monument usually refers to a stone
or concrete station marker containing a special bronze plate on which the
exact station point is marked |
| MOS |
military
occupational specialty |
| movement
area |
the runways
(exclusive of apron areas), taxiways, and other areas of an airport/heliport,
which are used for taxiing, takeoff, and landing of aircraft. At airports/heliports
with a tower, specific approval for entry onto the movement area must be
obtained from ATC |
| MRSE |
mean radial
spherical error |
| MSL |
mean sea
level |
| MTP |
mission
training plan |
| multipath
errors |
errors caused
when one or more reflected signals, interfering with the main signal because
of their common time origin but different path lengths, are superimposed
with their relative phase offsets on the primary signal at the receiver.
Cyclic perturbations of the carrier are caused by this superimposition as
the various signals undergo changes in their relative phase offsets as the
geometric relation between the nearby and distant reflecting surfaces and
the satellite and receiver changes |
| multistation
reduction |
geodetic
parameters that are estimated at more than two stations using simultaneous
observations |
| n |
geoid height |
| N |
north |
| NA |
not applicable |
| NAD |
North American
Datum |
| NAD
27 |
North American
Datum of 1927 |
| NAD
83 |
North American
Datum of 1983 |
| nadir |
the point
of the celestial sphere that is directly opposite the zenith and vertically
downward from the observer |
| NAS |
National
Airspace System |
| National
Flight Data Center |
a facility
in Washington, District of Columbia, that was established by the FAA to
operate a central aeronautical information service for the collection, validation,
and dissemination of aeronautical data in support of the activities of the
government, industry, and the aviation community. The information is published
in the National Flight Data Digest (NFDD) |
| National
Flight Data Digest |
a daily
(except weekends and Federal holidays) publication of flight information
(appropriate to aeronautical charts or aeronautical publications) that provides
operational flight data which is essential to safe and efficient aircraft
operations |
| NATO |
North Atlantic
Treaty Organization |
| NAVAID |
navigational
aid |
| NAVAID
survey |
the process
of determining the position and/or elevation of one or more NAVAIDs and
adjunctive points on associated runways or extended runway centerlines.
A NAVAID survey that is performed as part of the OC survey is called a combined
NAVAID survey. A NAVAID survey that is not performed as part of a normal
OC survey is called a special NAVAID survey |
| NAVD
88 |
North American
Vertical Datum of 1988 |
| navigable
airspace |
airspace
at and above the minimum flight altitude that is prescribed in FARs, including
airspace needed for safe takeoff and landing |
| navigational
aid |
any visual
or electronic device, airborne or on the surface, which provides point-to-point
guidance information or position data to aircraft in flight |
| NAVSTAR |
Navigation
Satellite Timing and Ranging |
| NBC |
nuclear,
biological, and chemical |
| NCAD |
New Cumberland
Army Depot |
| NCO |
noncommissioned
officer |
| NCOIC |
noncommissioned
officer in charge |
| NDB |
nondirectional
beacon |
| NE |
northeast |
| NFDD |
National
Flight Data Digest |
| NGRS |
National
Geodetic Reference System |
| NGS |
National
Geodetic Survey |
| NGVD
29 |
National
Geodetic Vertical Datum of 1929 |
| NIMA |
National
Imagery and Mapping Agency |
| NL |
notes and
legends |
| No. |
number |
| NOAA |
National
Oceanic and Atmospheric Administration |
| nondirectional
beacon |
an L/MF
or UHF radio beacon transmitting nondirectional signals whereby the pilot
of an aircraft that is equipped with direction-finding equipment can determine
his bearing to or from the station. When the NDB is installed in conjunction
with an ILS marker, it is normally called a compass locator |
| nonprecision
approach procedure |
a standard
instrument-approach procedure in which no electronic glide slope is provided
(for example, VOR, TACAN, NDB, localizer, ASR, and simplified directional
facility [SDF] approaches) |
| North
American Datum |
the initial
point of this datum is located at Meades Ranch, Kansas. Based on the Clarke
spheroid of 1866, the geodetic positions of this system are derived from
a readjustment of the triangulation of the entire country in which Laplace
azimuths were introduced |
| Nov |
November |
| NSATS |
number of
satellites |
| NSRS |
National
Spatial Reference System |
| NW |
northwest |
| obs |
observed |
| observer's
meridian |
a celestial
meridian passing through the zenith (at the point of observation) and the
celestial poles |
| obstruction |
any object
that penetrates a specified surface. An object that penetrates a supplemental
surface is a supplemental obstruction. The most obstructing object in a
set of objects is the one that penetrates an imaginary surface further than
any other object in the set |
| OC |
obstruction
chart |
| occ |
occupied |
| OCONUS |
outside
continental United States |
| Oct |
October |
| ODALS |
Omnidirectional
Approach Light System |
| offset
line |
a supplementary
line that is close to and roughly parallel with a main line (measured offsets).
When a line for which data are desired is in such a position that it is
difficult to measure over it, the required data are obtained by running
an offset line in a convenient location and measuring offsets from it to
salient points on the other line |
| OIS |
obstruction
identification surface |
| OM |
outer marker |
| op |
operator |
| open
traverse |
a survey
traverse which begins from a station of known or adopted position but does
not end upon such a station |
| OPORD |
operation
order |
| order
of accuracy |
a mathematical
ration that defines the general accuracy of measurements made in a survey
(for example, first, second, third, fourth, or lower order) |
| ortho |
orthometric |
| orthometric
height |
another
name for the elevation of an object (the height of an object above the geoid) |
| OTF |
on the fly |
| OVM |
organization
vehicle maintenance |
| p |
page(s) |
| PAC |
Personnel
and Administration Center |
| PACS |
primary
airport control station |
| PADS |
Position
and Azimuth Determination System |
| PAPI |
precision
approach-path indicator |
| PAR |
precision
approach radar |
| parallax |
the apparent
displacement or the difference in apparent direction of an object as seen
from two different points not on a straight line with the object; also,
the angular difference in direction of a celestial body as measured from
two points on the earth's orbit |
| PBM |
permanent
benchmark |
| PC |
personal
computer |
| P-code |
precision
code |
| PDOP |
positional
dilution of precision |
| permanent
benchmark |
a BM of
as nearly permanent character as it is practicable to establish. Usually
designated simply as BM. A PBM is intended to maintain its elevation with
reference to an adopted datum, without change, over a long period |
| PFC |
private
first class |
| pgdn |
page down |
| pgs |
pages |
| pgup |
page up |
| picture
point |
a terrain
feature that is easily identified on an aerial photograph and whose horizontal
or vertical position or both have been determined by survey measurements.
Picture points are marked on the aerial photographs by the surveyor and
are used by the photomapper |
| PIR |
precise
instrument runway |
| PLASI |
pulse-light
approach-slope indicator |
| PLGR |
precise
lightweight GPS receiver |
| plumb
line |
the line
of force in a geopotential field; the continuous curve to which the direction
of gravity is everywhere tangential; or, the line indicated by a plumb-bob
cord |
| PM |
post meridian |
| PMCS |
preventive-maintenance
checks and services |
| POC |
point of
contact |
| POL |
petroleum,
oils, and lubricants |
| pos |
position |
| POV |
privately
owned vehicle |
| ppm |
part(s)
per million |
| PPS |
Precise
Positioning Service |
| PRC |
pseudorange
correction |
| precise
ephemeris |
the precise
ephemeris is the postprocessed position of a satellite in its orbit as a
function of time. It is computed from data that are observed at tracking
stations at fixed locations and is available from various global agencies |
| precision
approach procedure |
a standard
instrument-approach procedure in which an electronic glide slope is provided
or used (for example, ILS and PAR approaches) |
| precision
approach radar |
radar equipment
usually located at military or joint-use airfields that detects and displays
azimuth, elevation, and range of aircraft on the final approach course to
a runway. The controller issues guidance to the pilot based on the aircraft's
position and elevation relative to the touchdown point on the runway displayed
on the radarscope |
| prime
meridian |
the specific
meridian (for example, line of longitude) that is assigned the value of
zero and to which all other meridians are referenced. While Greenwich, England,
is almost universally accepted as the prime meridian, several other meridians
(such as the meridian of Paris) remain in use |
|
prime
vertical
|
the vertical
circle through the east and west points of the horizon. It may be true,
magnetic, compass, or grid depending upon which east or west points are
involved |
| PRN |
pseudorandom
noise |
| pseudorange
measurement |
a measurement
obtained by comparing the time signal generated by the satellite clock to
the time signal generated by the receiver clock to determine propagation
time and, subsequently, the range |
| PVC |
polyvinyl
chloride |
| PX |
post exchange |
| r |
degrees
of freedom |
| R1 |
reject value,
use first mean value |
| R2 |
reject value,
use second mean value |
| radar |
a device
for radio detection and ranging. Radar measures the time interval between
transmitted and received radio pulses and provides information on the range,
azimuth, and/or elevation of objects in the path of the transmitted pulse.
A primary radar system uses reflected radio signals. A secondary radar system
is a system wherein a radio signal that is transmitted from a radar station
initiates the transmission of a radio signal from another station |
| radar
approach |
an instrument-approach
procedure that uses PAR or ASR |
| RC |
ratio of
closure |
| RDOP |
relative
dilution of precision |
| REIL |
runway end
identifier light |
| rep |
repetition |
| right
ascension |
the angular
distance that is measured eastward on the equator from the vernal equinox
to the hour circle through the celestial body, from 0 to 24 hours |
| RM |
reference
mark |
| RMS |
root-mean-square |
| Ro |
rejected
by observation |
| RPP |
runway plans
and profiles |
| RT |
relocated
threshold |
| RTCM |
Radio Technical
Commission for Maritime |
| RTK |
real-time
kinematic |
| RTO |
radio/telephone
operator |
| runway |
a defined
rectangular area on a land airport that is prepared for the landing and
takeoff run of aircraft along its length |
| RVR |
runway visual
range |
| RVV |
runway visibility
value |
| rwy |
runway |
| s |
seconds |
| S |
south |
| S1 |
Adjutant
(United States Army) |
| S3 |
Operations
and Training Officer (United States Army) |
| S4 |
Supply Officer
(United States Army) |
| S/A |
selective
availability |
| SACS |
secondary
airport control station |
| sampling
interval (data rate) |
the interval
(in seconds) at which observations are logged to memory |
| SATO |
Scheduled
Airline Ticket Office |
| SC |
special
committee |
| SCP |
survey control
point |
| SDF |
simplified
directional facility |
| SDNCO |
staff duty
noncommissioned officer |
| SE |
southeast |
| secs |
seconds |
| Sep |
September |
| SEP |
spherical
error probable |
| sexagesimal
system |
a system
of notation by increments of 60 (the division of a circle into 360�, each
degree into 60 minutes, and each minute into 60 seconds) |
| SFC |
sergeant
first class |
| SGT |
sergeant |
| SIC |
survey information
center |
| SIF |
stadia-interval
factor |
| simplified
directional facility |
a NAVAID
that is used for nonprecision instrument approaches. The final approach
course is similar to that of an ILS localizer, except that the SDF course
may not be aligned with the runway and the course may be wider, resulting
in less precision |
| sin |
sine |
| SINCGARS |
Single-Channel
Ground-to-Air Radio System |
| SLC |
sea-level
coefficient |
| SM |
soldier's
manual |
| software |
GPS software
is classified as data logging, postprocessing reduction, and real-time processing.
Data-logging software relates to the operation of the receiver and is not
field-tested. Postprocessing software should be tested using a BM data set |
| SOI |
signal operation
instructions |
| solar
day |
the interval
of time from the transit of either the sun or the mean sun across a given
meridian to the next successive transit of the same body across the same
meridian; also, the duration of one rotation of the sun |
| solar
time |
time based
upon the rotation of the earth relative to the sun; time on the sun |
| SOP |
standing
operating procedure |
| SPC |
specialist |
| SPCE |
survey planning
and coordination element |
| SPCO |
survey planning
and coordinating officer |
| spheroid |
any figure
differing slightly from a sphere |
| SPHS |
specially
prepared hard surface |
| spirit
leveling |
spirit leveling
follows the geoid and its associated level surfaces, which are irregular
rather than any mathematically determined spheroid or ellipsoid and associated
regular level surfaces |
| SPS |
Standard
Positioning Service |
| SSF |
standard
solution file |
| SSG |
staff sergeant |
| SSGCN |
Standards
and Specifications for Geodetic Control Networks |
| SSI |
standing
signal instructions |
| ST |
special
text |
| sta |
station |
| state-plane
coordinate system |
the meridian
used as the axis of Y for computing projection tables for a state coordinate
system (the CM of the system usually passes close to the center of the figure
of the area or zone for which the tables are computed) |
| std |
standard |
| stopway |
an area
beyond the takeoff runway that is at least as wide as the runway, is centered
upon the extended runway centerline, is able to support an airplane during
an aborted takeoff without causing structural damage to the airplane, and
is designated by airport authorities for use in decelerating the airplane
during an aborted takeoff. The location of threshold lights has no bearing
on an area being designated as a stop way |
| STP |
soldier
training publication |
| sub |
subtract |
| SV |
satellite
vehicle |
| t |
grid azimuth |
| T |
geodetic
azimuths |
| TA |
target acquisition |
| TAB |
target-acquisition
battery |
| TACAN |
tactical
air navigation |
| tactical
air navigation |
a UHF electronic
rho-theta air NAVAID, which provides suitably equipped aircraft with a continuous
indication of bearing and distance to the TACAN station |
| tan |
tangent |
| target |
any object
or point toward which something is directed; also, an object which reflects
a sufficient amount of a radiated signal to produce an echo signal on detection
equipment |
| TBM |
temporary
benchmark |
| TCMD |
transportation-control
and movement document |
| TDY |
temporary
duty |
| TDZE |
touchdown
zone elevation |
| TEC |
Topographic
Engineering Center |
| TECHOPORD |
technical
operation order |
| tel |
telescope |
| temp |
temperature |
| TG |
trainer's
guide |
| thr |
threshold |
| threshold |
the beginning
of that portion of the runway usable for landing. A DT is located at a point
on the runway other than the designated beginning of the runway. The displaced
area is available for takeoff or rollout of aircraft. The DT paint bar is
entirely on the usable landing surface. A relocated threshold (RT) is located
at a point on the runway other than the beginning of the full strength pavement.
The area between the former threshold and the RT is not available for the
landing or takeoff of aircraft. The abandoned runway area may or may not
be available for taxiing |
| tidal
benchmark |
a BM set
to reference a tide staff at a tidal station and the elevation that is determined
with relation to the local tidal datum |
| tidal
datum |
specific
tide levels, which are used as surfaces of reference for depth measurements
in the sea and as a base for the determination of elevation on land. Many
different datums have been used, particularly for leveling operations |
| TM |
technical
manual |
| TMP |
transportation
motor pool |
| TOD |
tabulated
operational data |
| TOE |
table(s)
of organization and equipment |
| topo |
topographic |
| touchdown
zone |
the first
3,000 feet of the runway beginning at the threshold |
| touchdown
zone elevation |
the highest
elevation in the touchdown zone. The OC program specifications require that
the TDZE will be determined only for runways with SPHSs equal to, or greater
than, 3,000 feet in length |
| TP |
temporary
point |
| TRADOC |
United States
Army Training and Doctrine Command |
| transit |
the apparent
passage of a star or another celestial body across a defined line of the
celestial sphere, as a meridian, prime vertical, or almucantar; the apparent
passage of a star or another celestial body across a line in the reticle
of a telescope, or some line of sight; a theodolite with the telescope mounted
so that it can be transited |
| transmissometer |
an apparatus
used to determine visibility by measuring the transmission of light through
the atmosphere and is the measurement source for determining runway visual
range (RVR) and runway visibility value (RVV) |
| trig
list |
an extremely
or excessively precise list |
| tropospheric
correction |
the troposphere
causes a propagation delay of a GPS signal. This delay can be estimated
using any recognized atmospheric model and can be mostly eliminated by relative
positioning for short lengths and modeled for longer baselines |
| UDS |
user-defined
sequence |
| UERE |
user equivalent
range error |
| UHF |
ultrahigh
frequency |
| universal
transverse Mercator |
a series
of 120 coordinate systems that are based on the transverse Mercator projection
that was originally developed by the US Army for a worldwide mapping project.
Sixty zones are used to map the northern hemisphere, and the remaining zones
apply to the southern hemisphere. Each zone is 6� wide and is numbered.
Zone 1 covers longitudes of 180� W through 174� W. The remaining zones are
numbered sequentially as they move east. All zones have their origin at
the equator, use the meter as the system unit, and have a false easting
of 500,000 meters and a false northing of 0. A scale reduction factor of
0.9996 is used on all zones. Zones for the southern hemisphere are identical
to their northern counterpart except that the false northing is set to 10,000,000
to eliminate negative Y coordinates |
| UPS |
universal
polar stereographic |
| US |
United States
|
| USA |
United States
of America |
| USAADCENFB |
United States
Army Air Defense Center and Fort Bliss |
| USAASA |
United States
Army Aeronautical Services Agency |
| USACE |
United States
Army Corps of Engineers |
| USAES |
United States
Army Engineer School |
| USAF |
United States
Air Force |
| USAPA |
United States
Army Publishing Agency |
| USAPPC |
United States
Army Publications and Printing Command |
| USCG |
United States
Coast Guard |
| USC&GS |
United States
Coast and Geodetic Survey |
| USGS |
United States
Geological Survey |
| UTC |
universal
time, coordinated |
| UTM |
universal
transverse Mercator |
| VASI |
visual-approach
slope indicator |
| VDOP |
vertical
dilution of precision |
| vern |
vernier |
| vernal
equinox |
that point
of intersection of the ecliptic and the celestial equator, which is occupied
by the sun as it changes from south to north declination on or about March
21 (same as the first of Aries, the first point of Aries, or the March equinox) |
| vert |
vertical |
| vertical
circle |
a great
circle of the celestial sphere (through the zenith and nadir) that is perpendicular
to the horizon; also, a graduated disk (mounted on an instrument in such
a manner that the plane of its graduated surface can be placed in a vertical
plane), which is used primarily for measuring vertical angles in astronomical
and geodetic work |
| vertical
control |
the measurements
taken by surveying methods for the determination of elevation only with
respect to an imaginary level surface, usually the MSL |
| vertical-control
datum |
any level
surface (for example, the MSL) taken as a surface of reference from which
to reckon elevations. Although a level surface is not a plane, the vertical-control
datum is frequently referred to as the datum plane |
| very-high-frequency
omnidirectional range |
a VHF NAVAID,
which provides suitably equipped aircraft with a continuous indication of
bearing to the VOR station |
| very-high-frequency
omnidirectional range and tactical air navigation |
a navigational
facility consisting of two components, a VOR and a TACAN, which provide
VOR azimuth, TACAN azimuth, and TACAN distance |
| VFR |
visual flight
rules |
| VHF |
very high
frequency |
| VOR |
very-high-frequency
omnidirectional range |
| VORTAC |
very-high-frequency
omnidirectional range and tactical air navigation |
| W |
west |
| WAAS |
wide-area
augmentation system |
| WDI |
wind-direction
instrument |
| WGS |
World Geodetic
System |
| WGS
72 |
World Geodetic
System 1972 |
| WGS
84 |
World Geodetic
System 1984 |
| widelaning |
a linear
combination of the measured phases of L1 and L2, based on the frequency
difference. Widelane ambiguities can be resolved easier than L1 and L2 ambiguities,
because the resulting 0.862-meter wavelength is much longer than the individual
L1 and L2 wavelengths. Knowledge of the widelane ambiguity helps to solve
the L1 ambiguity, after which a simple computation will give the L2 ambiguity |
| World
Geodetic System 1984 |
a global
datum that is based on electronic technology, which is still to some degree
classified. Data on the relationship of as many as 65 different datums to
WGS-84 is available to the public. As a result, WGS 84 is becoming the base
datum for the processing and conversion of data from one datum to any other
datum. GPS is based on this datum. The difference between WGS 84 and NAD
83 is small and is generally considered to be insignificant |
| XVIII |
the Table
18 value extracted from DMS
ST 045 |
| X,
Y, and Z |
variables
used to depict coordinates in the X, Y, and Z axis |
| Y-code |
the military's
classified, encrypted precision code |
| yr |
year(s) |
| ZD |
zenith distance |
| zen |
zenith |
| zenith |
the point
where an infinite extension of a plumb (vertical) line, at the observer's
position, pierces the celestial sphere above the observer's head |
| zenith
distance |
the complement
of the altitude; the angular distance from the zenith of the celestial body
measured along a vertical circle |