FM 6-2 Glossary

GLOSSARY

AC alternating current

accuracy: the degree of conformity with a standard

ADD additional (BUCS)

AE allowable radial error

AFATDS advanced field artillery tactical data system

AFG Afgooye (BUCS)

AFSO aerial fire support observer

AHIP advanced helicopter improvement program

ALB AirLand Battle

altitude: the altitude of a celestial body is the arc of its vertical circle measured from the observer's horizon to the body, or it is the vertical angle at the observer's position between the horizon and the body

am ante meridiem

amp ampere

angle t: the interior angle of the PZS triangle at the pole. It is measured either eastward or westward between the observer's meridian and the hour circle of the celestial body.

AOC area of concentration

approx approximately

AR accuracy ratio (also with BUCS)

ARTEP Army training and evaluation program

arty artillery

*AS antispooling

astro astronomic

astro alt astronomic observation (altitude method)

az azimuth

AZ azimuth (BUCS)

azimuth: the horizontal angle measured clockwise between a reference direction and the line to an observed or designated point

azimuth angle: the angle less than 180° between the plane of the celestial meridian and the vertical plane containing the observed object, reckoned from the direction of the elevated pole. In astronomic work, the azimuth angle is the spherical angle at the zenith in the astronomical triangle composed of the pole, the zenith, and the star.

azimuth astronomic: the angle between the plane of the observer's meridian and the plane of the hour circle containing the observed body, measured in the plane of the horizon, preferably clockwise from north

azimuth, geodetic: the angle between the geodetic meridian and the tangent to the geodetic line at the observer, measured in the plane perpendicular to the ellipsoidal normal of the observer, preferably clockwise from north. (See survey, geodetic.)

azimuth, grid: an azimuth measured from grid north. (See azimuth, plane and azimuth, projected geodetic.)

azimuth magnetic: an azimuth measured from magnetic north

azimuth, plane: the angle measured in a clockwise direction between grid north and a line on the grid

azimuth, projected geodetic: at the point of observation, the horizontal angle measured clockwise between grid north and the tangent to the geodetic line to an observed or designated point. This term must not be confused with geodetic azimuth.

az mk azimuth mark

AZMK azimuth mark (BUCS)

AZ/MK azimuth to azimuth mark (BUCS)

B₀ B₀ in FM 6-300, Tables 12a through e

B₁ B₁ in FM 6-300, Tables 12a through e

B₂ B₂ in FM 6-300, Tables 12a through e

BA=1 side of triangle between Points A and B (BUCS)

baseline: a surveyed line, established with more than usual care, to which surveys are referred for coordination and correlation; used as a known length of a triangle side for computing other triangle sides. When misinterpretation is not probable, the abbreviation term base may be used.

basic control: horizontal or vertical control, in which the locations of the stations have been accurately coordinated and correlated and forming a framework to which other surveys are adjusted. For artillery purposes, this term can be applied to control points established by fourth-order accuracy or higher orders of accuracy.

BC battery center

B/C Point B or C (BUCS)

BCS battery computer system

bde brigade

bldg building

blvd boulevard

bn battalion

bn SCP battalion survey control point

BOIP basis of issue plan

BRP boresight reference point

btry battery

BUCS backup computer system

BWI British West Indies

C Celsius

*CA comparative accuracy (BUCS); course acquisition

CA=2 side of triangle between Points C and A (BUCS)

cav cavalry

CDU control and display unit (PADS)

celestial coordinates: the coordinates used to locate a heavenly body by various systems. The coordinates used in the field artillery are declination and right ascension.

celestial equator: the great circle on the celestial sphere whose plan is perpendicular to the axis of rotation of the earth. A great circle is a circle, the plane of which passes through the center of a sphere.

celestial horizon: that circle on the celestial sphere formed by the intersection of the celestial sphere and a plane through the center of the earth and perpendicular to the zenith-nadir line

celestial North and South Poles: the points at which the prolonged polar axis of the earth intersects the celestial sphere

celestial sphere: an imaginary sphere of indefinitely large radius whose center is the center of the earth. (Practical astronomy assumes that the earth is stationary and that the celestial bodies rotate about the earth from east to west on this sphere.)

CEP circular error probable

CEWI combat electronic warfare intelligence

ck check

CK check (BUCS)

CM central meridian

cmd command

colatitude: the side of the PZS triangle from the celestial pole to the zenith. The complement of altitude, or 90° minus the altitude. The term has significance only when used in connection with altitude measured from the celestial horizon, when it is synonymous with zenith distance.

C2 command and control

CMPTD computed (BUCS)

COLT combat observation/lasing team

comm communication

cont continue

CONUS continental United States (also in BUCS)

CONV conversion (BUCS)

CONVG convergence (BUCS)

COP chief of party

CORR correction (BUCS)

COS cosine (BUCS)

cot cotangent

CPT captain

CST central standard time

CTOC corps tactical operations center

CTR center (BUCS)

CUCV commercial utility cargo vehicle

culmination: the passage of the celestial body across the meridian of the observer. Every celestial body will have two culminations. The passage across the upper branch of the observer's meridian is upper culmination (or upper transit), and the passage across the lower branch is lower culmination (or lower transit).

CVG convergence (BUCS)

D direct

(D) direct (BUCS)

DA Department of the Army; Denmark (STANAG)

datum: a reference element, such as a line or plane, by reference to which the positions of other elements are determined. (See datum, horizontal and datum, sea level.)

datum, horizontal: in plane surveying, the grid system of reference used for the horizontal control of an area, defined by the easting and northing of one station in the area and the azimuth from this selected station to an adjacent station. This term is differentiated from the term common grid in that the latter implies a common datum.

datum, sea level: a level surface to which heights are referred. The generally adopted level datum is mean sea level. For tactical surveys, an arbitrary level datum is often assumed, as in the case of some local surveys in which arbitrary level datums are often adopted and defined in terms of an assumed elevation for some physical mark (bench mark).

DAYLT daylight (BUCS)

*db decibel

DC direct current; daily change (BUCS)

DD.MMSS degrees, minutes, seconds (BUCS)

DD.MMYY day, month, year (BUCS)

DDCT datum-to-datum coordinate transformations

dE difference in easting

declination: the angular distance from the celestial equator measured along the hour circle of the celestial body. Declination is positive when the body is north of the celestial equator and negative when it is south of the celestial equator. Declination corresponds to latitude to the earth.

DECLN declination (BUCS)

DEF defined (BUCS)

dH difference in height

dist distance

DIST distance (BUCS)

distance, horizontal: the distance measured in a horizontal plane, as distinguished from a distance measured on a scope. Horizontal distance refers primarily to taped distances or to distances reduced to horizontal by computations.

div arty division artillery

DMA Defense Mapping Agency

dN difference in northing

*DoD Department of Defense

DOS Director of Overseas Survey

DS direct support

DST daylight saving time

*DTM datum (AN/PSN-11)

E east; easting (BUCS)

EAC echelon above corps

ECCM electronic counter-countermeasures

*ECEF earth-centered, earth-fixed

ecliptic: the great circle formed on the celestial sphere by the plane of the orbit of the earth. If one could observe the sun and the stars at the same time, he would see the sun and stars moving slowly across the sky, with the sun gaining slightly on the stars each day. Therefore, since for purposes of practical astronomy the earth is assumed to be stationary, the ecliptic is assumed to be the path of the sun. This ecliptic intersects the celestial equator at two points at an angle of 23.50.

ECU electronic control unit (SIAGL)

eE error in easting

el elevation

electronic line of sight: the characteristics of intervening terrain that make possible the transmission of a radio wave between two separated components of the electronic distance-measuring equipment systems

elongation: the elongations of a celestial body are two points in its apparent orbit at which the bearing from the observer's meridian is the greatest. A star is said to be at eastern elongation when its bearing is at its maximum to the east and at western elongation when its bearing is at its maximum to the west.

*ElHold elevation hold (AN/PSN-11)

ELPS ellipsoid (BUCS)

eN error in northing

engr engineer

EOL end of orienting line

equinox: the equinoxes are the two ponts where the ecliptic intersects the celestial equator. The point where the apparent annual path of the sun crosses the celestial equator from south to north is called the vernal equinox, or first point of Aries. The other pint is called the autumnal equinox, where the sun is on the celestial equator diametrically opposite the vernal equinox. The equinoctial points move slowly westward along the ecliptic at a rate of about 50 seconds a year. As a result, all the fixed stars gradually change their positions with respect to the equator and the vernal equinox.

F Fahrenheit; fast (BUCS); flattening (BUCS)

FA field artillery

FDC fire direction center

FGCC Federal Geodetic Control Committee

FIST fire support team

1LT first lieutenant

FLAT flattening

FM frequency modulated; field manual

FO forward observer

*FOM figure of merit (AN/PSN-11)

FP firing point

FRAGO fragmentary order

FRIG French Frigate Shoals

FS fire support

FSCOORD fire support coordinator

FSE fire support element

FSTK far stake

FWD forward (BUCS)

GAT Greenwich apparent time

GAZ grid azimuth

geo geographic

GEO geographic (BUCS)

GHA Greenwich hour angle

GK Gauss-Kruger

GMD Greenwich mean date

GMT Greenwich mean time

GN grid north

GPS global positioning system

GR.BRIT Great Britain (BUCS)

GRS global reference system

GRU gyroscopic reference unit (SIAGL)

GS general support

GSR general support reinforcing

GST Greenwich sidereal time

gyro gyroscopic

H height

HHB headquarters and headquarters battery

HHC headquarters and headquarters company

HH.MMSS hours, minutes, seconds

HI height of instrument

HMMWV high-mobility multipurpose wheeled vehicle

horiz horizontal

horizon: the horizon for any place on the surface of the earth is the great circle formed on the celestial sphere by the extension of the plane of the observer's horizon. In general, the apparent or visible junction of earth and sky as seen from any specific position.

hour angle: the angle at the celestial poles between the plane of the observer's meridian and the plane of the hour circle of the star. Stated simply, the hour angle is the angle at the pole between the observer's meridian and the meridian (hour circle) of the celestial body. This angle is similar to differences in longitude on the earth's surface. It is measured westward from the observer's meridian. Generally, the angle is considered as an arc measured along the celestial equator toward the west and is expressed in units of time or arc.

hour circle: any great circle on the celestial sphere whose plane is perpendicular to the plane of the celestial equator

HQ headquarters

HRS hours (BUCS)

HT height of target; height (BUCS)

HT/I height of instrument (BUCS)

HT/T height of target (BUCS)

hvy heavy

hwy highway

Hz hertz

HZ horizontal (BUCS)

ID identification

IEW intelligence and electronic warfare

IGN Institute Geographic Nationally

IMU inertial measuring unit (PADS)

inst instrument

IO instrument operator

IRR infrared reflector

ISTS International Satellite Tracking Station

IT Italy (STANAG)

*IUGG International Union of Geodesy and Geophysics

km kilometer

KN known (BUCS)

L left (BUCS); leading (BUCS)

lat latitude

LAT latitude (BUCS)

latitude: the angular distance, for a specific spot on the surface of the earth, from 00 to 90° north or south of the equator

LC Lesser Cayman Island

LDG leading edge (BUCS)

LF left (BUCS)

LG longitude (BUCS)

LHA local hour angle

LID light infantry division

LIN line information number

LNG longitude (BUCS)

long longitude

longitude: the angular distance, for a specific spot on the surface of the earth, from 00 to 180° east or west of the Greenwich meridian, which is used by most nations as the prime or initial meridian

LMT local mean time

LRIP low-rate initial production

LS launcher site

LST local sidereal time (also in BUCS)

lt light

ltr letter

mil

m meter

M minor (BUCS)

MAJ major

MAJOR semimajor axis (BUCS)

mal malfunction

*MAPS modular azimuth positioning system

MEAS measure (BUCS)

met meteorological

METT-T mission, enemy, terrain and weather, troops and time available

MHz megahertz

MIN minutes (BUCS)

MINOR semiminor axis (BUCS)

MLRS multiple launch rocket system

mm millimeter

MMSS minutes, seconds (BUCS)

MMSSS minutes, seconds to the nearest tenth (BUCS)

mn mean

MN mean (BUCS)

MOS military occupational specialty

MS measuring section

*MSL mean sea level

MSN mission (BUCS)

mt mountain

MTLR moving-target-locating radar

MTOE modification tables of organization and equipment

M/V manpack/vehicular

N north; northing (BUCS)

NAD North American datum

NBC nuclear, biological, chemical

NICAD nickel-cadmium

no number

NO Norway (STANAG)

NOAA National Oceanic and Atmospheric Administration

NREF north reference point

*NSG north-seeking gyroscope

NSN national stock number

O1 Observer 1 (or Observation Post 1)

O2 Observer 2 (or Observation Post 2)

OBS observation (BUCS)

observer's meridian: the great circle on the celestial sphere that passes through the celestial poles and the observer's zenith-nadir

obsr observer

OCC occupied (BUCS)

OL orienting line

OMB Office of Management and Budget

one-position, two-position: refers to initial readings on the circle of the instrument measuring an angle and is used to determine the degree of refinement in the performance of angular value determinations with the theodolite

OP observation post

oper operator

OPORD operation order

OPS observation posts (BUCS)

ORD ordnance (BUCS)

OS orienting station

P Point P (BUCS)

PADS position and azimuth determining system

PAE position, azimuth, elevation (PADS)

parallax: the difference in altitude of a body as seen from the center of the earth and from a point on the surface of the earth. There is no apparent parallax of the fixed stars, but that of the sun and planets is measurable. Parallax makes the body appear lower than it actually is; therefore, the correction is added.

PASP platoon area survey point

PDS position determining system

PE probable error

PFC private first class

PGM program (BUCS)

PLGR precise lightweight GPS receiver

plt platoon

pm post meridiem

PMCS preventive maintenance checks and services

polar distance: the algebraic complement of the declination (90° minus the declination)

pos position

POS position (BUCS)

PPM parts per million

*PPS precise positioning system

prime vertical: the vertical circle that is perpendicular to the plane of the observer's meridian and intersects the celestial horizon at the points directly true east and west of the observer's meridian

pro forma: provided in advance to prescribe form or to describe items (according to form)

PROV provisional (BUCS)

PS power supply (PADS)

PT point (BUCS)

PTS points (BUCS)

*P/Y precise (PPS code)

R reverse; right (BUCS); reinforcing

RA right ascension (also in BUCS)

RAM random-access memory

RATELO radiotelephone operator

rcdr recorder

rd road

RDG reading (BUCS)

RE radial error of closure; radial error (BUCS)

RECIP reciprocal (BUCS)

recon reconnaissance

recip reciprocal

RECIP reciprocal (BUCS)

REFR refraction (BUCS)

refraction: the refraction of a celestial body is the apparent displacement of the body caused by the bending of light rays passing through layers of air of varying density. The celestial body will appear higher than it really is; therefore, the correction is subtracted. A simple example of refraction can be seen by placing a spoon in a glass half full of water.

rejection limit: used in FA survey to refer to a maximum allowable deviation from a mean value of two or more angular measurements

REQD required (BUCS)

restitution point: a point identifiable on a photograph for which a chart location is known and which is used to transfer (restitute) other points from the photograph to the firing chart. The chart locations of these points may be determined by inspection or by survey.

REV revision (BUCS)

revolution: the turning of a body about an exterior point or axis. The earth revolves about the sun on a 600-million-mile orbit at a speed of about 18.5 miles per second. Practical astronomy assumes that the earth is stationary and the celestial bodies move about it from east to west on the celestial sphere.

RF radio frequency

right ascension: the right ascension of a celestial body is the arc on the celestial equator measured from the vernal equinox eastward to the hour circle of the body. It is measured in units of time from 0 to 24 hours. Right ascension corresponds to longitude on earth.

rotation: the turning of a body on its axis. The terminal points of the axis of the earth are the North and South Poles. The rotation is from west to east.

RP registration point

*R3SP rearm, refuel, resupply, and survey point

RSO reconnaissance and survey officer

RSOP reconnaissance, selection, and occupation of position

RT right (BUCS)

S south (also in BUCS)

*SA selective availability

SCH scheme (BUCS)

SCP survey control point

SDT self-development test

sec second

SEC second (BUCS)

SEDME-MR survey equipment, distance-measuring, electronic (medium-range)

set (one set, two sets, and so on): used in reference to astronomic observations of a celestial body. One set consists of the field data that result from the observation of a celestial body with the telescope of the observing instrument, first in the direct position, then in the reverse position.

SFC sergeant first class

*SGS Soviet Geodetic System

SGT sergeant

*SHTU simplified hand-held terminal unit

SIAGL survey instrument, azimuth gyro, lightweight

SIC survey information center

sidereal time: time determined by the stars

SIDRL sidereal (BUCS)

SIMO simultaneous observation

sin sine

SIN sine (BUCS)

SL slope (BUCS)

SLGR small lightweight GPS receiver

slope distance: the straight-line distance between two points of unequal heights. Normal usage is associated with electronic distance-measuring equipment. (Do not use the term slant distance.)

SM soldier's manual

SO south (BUCS)

SOI signal operation instructions

SOJT supervised on-the-job training

solar time: time determined by the sun

solstices: the solstices are two points on the ecliptic midway between the equinoxes. When the ecliptic is north of the celestial equator, the midpoint is called the summer solstice and occurs about 21 June. When the ecliptic is south of the celestial equator, the midpoint is called the winter solstice and occurs about 21 December. As can easily be seen, the solstices occur when the sun is at its greatest distance north or south of the equator.

SOP standing operating procedure

SOR Sorol

SPC specialist

SPCE survey planning and coordination element

SPCO survey planning and coordination officer

sph spheroid

*SPS standard positioning system

SRP/PDS stabilization reference package/position-determining system

SSG staff sergeant

sta station

STA station (BUCS)

STP soldier training publication

SUBT subtended or subtense (BUCS)

SURV survey (BUCS)

survey, geodetic: survey that takes into consideration the size and shape of the earth; implies a reference spheroid that mathematically represents the geoid and the horizontal and vertical control datums

survey, plane: those survey procedures common to field artillery in which the effect of the curvature of the earth is almost entirely neglected, and computations of the relative positions of the stations are made by using the principles of plane geometry and plane trigonometry

SUSV small-unit support vehicle

*SV satellite vehicle (AN/PSN-11)

svy survey (radio net)

SW southwest

SYS system (BUCS)

T telescope (field notebook)

TA target acquisition

TAB target acquisition battery

TACFIRE tactical fire direction system

TAN tangent (BUCS)

TASCP target area

TA2 true azimuth

TBL table (BUCS)

temp temperature

TG trainer's guide

tgt target survey control point

Thai Thailand (BUCS)

theod theodolite

TM technical manual

TOC tactical operations center

TOE tables of organization and equipment

topo topographic

TR trailing edge (BUCS)

trig triangulation

TRIG TRAV trig traverse (BUCS)

TRL trailing edge (BUCS)

TS traverse station

TTL total traverse length

tundra treeless plain in arctic regions

TZ time zone (BUCS)

U/A unadjusted/adjusted

unk unknown

UNK unknown (BUCS)

updt updated(d)

*UPS universal polar sterographic

UTM universal transverse mercator (also in BUCS)

V voice (radio net)

VA vertical angle (also in BUCS)

v DC volts direct current

VE vernal equinox

vert vertical

vertical circle: any great circle on the celestial sphere that passes through the observer's zenith-nadir

VHF very high frequency

Viet Vietnam (BUCS)

w/ with

W west (also in BUCS); watch (BUCS)

WC watch correction

WGS world geodetic system (BUCS)

WLR weapons-locating radar

WT water tower

XO executive officer

Y/N yes/no (BUCS)

zenith-nadir: the zenith and nadir for any place on the surface of the earth are two points where an extension of the observer's plumb line intersects the celestial sphere. The zenith is the point directly overhead, and the nadir is the point directly underneath.

Z-VEL zero velocity (PADS)

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GLOSSARY