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Military Terms and Definitions

half-life — (*) The time required for the activity of a given radioactive species to decrease
to half of its initial value due to radioactive decay. The half-life is a characteristic
property of each radioactive species and is independent of its amount or condition. The
effective half-life of a given isotope is the time in which the quantity in the body will
decrease to half as a result of both radioactive decay and biological elimination. (JP 3-11)

half-residence time — (*) As applied to delayed fallout, it is the time required for the
amount of weapon debris deposited in a particular part of the atmosphere to decrease to
half of its initial value.

half thickness — (*) Thickness of absorbing material necessary to reduce by one-half the
intensity of radiation which passes through it.

handling (ordnance) — Applies to those individuals who engage in the breakout, lifting, or
repositioning of ordnance or explosive devices in order to facilitate storage or stowage,
assembly or disassembly, loading or downloading, or transporting. See also assembly;
downloading; loading; ordnance. (JP 3-04)

handover — The passing of control authority of an aircraft from one control agency to
another control agency. Handover action may be accomplished between control
agencies of separate Services when conducting joint operations or between control
agencies within a single command and control system. Handover action is complete
when the receiving controller acknowledges assumption of control authority. Also
called hand-off.

handover/crossover — In personnel recovery, the transfer of isolated personnel between
two recovery forces. See also evader; evasion; recovery; recovery operations.
(JP 3-50)

handover line — (*) A control feature, preferably following easily defined terrain features,
at which responsibility for the conduct of combat operations is passed from one force to

hang fire — A malfunction that causes an undesired delay in the functioning of a firing

harassing fire — (*) Fire designed to disturb the rest of the enemy troops, to curtail
movement, and, by threat of losses, to lower morale. See also fire.

harassment — An incident in which the primary objective is to disrupt the activities of a
unit, installation, or ship, rather than to inflict serious casualties or damage.

harbor — A restricted body of water, an anchorage, or other limited coastal water area and
its mineable water approaches, from which shipping operations are projected or
supported. Generally, a harbor is part of a base, in which case the harbor defense force
forms a component element of the base defense force established for the local defense
of the base and its included harbor.

harbor defense — The defense of a harbor or anchorage and its water approaches against
external threats such as: a. submarine, submarine-borne, or small surface craft attack;
b. enemy minelaying operations; and c. sabotage. The defense of a harbor from
guided missiles while such missiles are airborne is considered to be a part of air
defense. See also port security.

hard beach — A portion of a beach especially prepared with a hard surface extending into
the water, employed for the purpose of loading or unloading directly into or from
landing ships or landing craft.

hardened site — (*) A site, normally constructed under rock or concrete cover, designed to
provide protection against the effects of conventional weapons. It may also be
equipped to provide protection against the side effects of a nuclear attack and against a
chemical or a biological attack.

hard missile base — (*) A launching base that is protected against a nuclear explosion.

hardstand — (*) 1. A paved or stabilized area where vehicles are parked. 2. Open
ground area having a prepared surface and used for the storage of materiel.

hardware — 1. The generic term dealing with physical items as distinguished from its
capability or function such as equipment, tools, implements, instruments, devices, sets,
fittings, trimmings, assemblies, subassemblies, components, and parts. The term is
often used in regard to the stage of development, as in the passage of a device or
component from the design stage into the hardware stage as the finished object. 2. In
data automation, the physical equipment or devices forming a computer and peripheral
components. See also software.

harmonization — The process and/or results of adjusting differences or inconsistencies to
bring significant features into agreement.

hasty attack — (*) In land operations, an attack in which preparation time is traded for
speed in order to exploit an opportunity. See also deliberate attack.

hasty breaching — (*) The rapid creation of a route through a minefield, barrier, or
fortification by any expedient method.

hasty breaching (land mine warfare) — The creation of lanes through enemy minefields
by expedient methods such as blasting with demolitions, pushing rollers or disabled
vehicles through the minefields when the time factor does not permit detailed
reconnaissance, deliberate breaching, or bypassing the obstacle.

hasty crossing — (*) The crossing of an inland water obstacle using the crossing means at
hand or those readily available, and made without pausing for elaborate preparations.
See also deliberate crossing.

hasty defense — (*) A defense normally organized while in contact with the enemy or
when contact is imminent and time available for the organization is limited. It is
characterized by improvement of the natural defensive strength of the terrain by
utilization of foxholes, emplacements, and obstacles. See also deliberate defense.

hatch — An opening in a ship’s deck giving access to cargo holds. (JP 4-01.6)

hatch list — A list showing, for each hold section of a cargo ship, a description of the items
stowed, their volume and weight, the consignee of each, and the total volume and
weight of materiel in the hold.

havens (moving) — See moving havens.

hazard — A condition with the potential to cause injury, illness, or death of personnel;
damage to or loss of equipment or property; or mission degradation. See also injury;
risk. (JP 3-33)

hazards of electromagnetic radiation to fuels — The potential hazard that is created when
volatile combustibles, such as fuel, are exposed to electromagnetic fields of sufficient
energy to cause ignition. Also called HERF. (JP 3-04)

hazards of electromagnetic radiation to ordnance — The danger of accidental actuation
of electro-explosive devices or otherwise electrically activating ordnance because of
radio frequency electromagnetic fields. This unintended actuation could have safety
(premature firing) or reliability (dudding) consequences. Also called HERO. See also
electromagnetic radiation; HERO SAFE ordnance; HERO UNSAFE ordnance;
ordnance. (JP 3-04)

hazards of electromagnetic radiation to personnel — The potential hazard that exists
when personnel are exposed to an electromagnetic field of sufficient intensity to heat
the human body. Also called HERP. (JP 3-04)

heading hold mode — In a flight control system, a control mode that automatically
maintains an aircraft heading that exists at the instant of completion of a maneuver.

heading indicator — (*) An instrument which displays heading transmitted electrically
from a remote compass system.

heading select feature — A flight control system feature that permits selection or
preselection of desired automatically controlled heading or headings of an aircraft.

head of contracting activity — The official who has overall responsibility for managing
the contracting activity. Also called HCA. (JP 4-10)

head-up display — (*) A display of flight, navigation, attack, or other information
superimposed upon the pilot’s forward field of view. Also called HUD. See also
flight; horizontal situation display. (JP 3-09.1)

health care provider — Any member of the Armed Forces, civilian employee of the
Department of Defense, or personal services contract employee under Title 10 United
States Code Section 1091 authorized by the Department of Defense to perform health
care functions. The term does not include any contract provider who is not a personal
services contract employee. Also called DOD health care provider. (JP 4-02)

health hazard assessment — An assessment that characterizes the possible health risks of
occupational exposures of Service members during the course of their normal duties.
(JP 4-02)

health service logistic support — A functional area of logistic support that supports the
joint force surgeon’s health service support mission. It includes supplying Class VIII
medical supplies (medical materiel to include medical peculiar repair parts used to
sustain the health service support system), optical fabrication, medical equipment
maintenance, blood storage and distribution, and medical gases. Also called HSLS.
See also health service support; joint force surgeon. (JP 4-02.1)

health service support — All services performed, provided, or arranged to promote,
improve, conserve, or restore the mental or physical well-being of personnel. These
services include, but are not limited to, the management of health services resources,
such as manpower, monies, and facilities; preventive and curative health measures;
evacuation of the wounded, injured, or sick; selection of the medically fit and
disposition of the medically unfit; blood management; medical supply, equipment, and
maintenance thereof; combat stress control; and medical, dental, veterinary, laboratory,
optometric, nutrition therapy, and medical intelligence services. Also called HSS.
(JP 4-02)

health surveillance — The regular or repeated collection, analysis, and interpretation of
health-related data and the dissemination of information to monitor the health of a
population and to identify potential health risks, thereby enabling timely interventions
to prevent, treat, reduce, or control disease and injury. It includes occupational and
environmental health surveillance and medical surveillance subcomponents. (JP 4-02)

health threat — A composite of ongoing or potential enemy actions; adverse
environmental, occupational, and geographic and meteorological conditions; endemic
diseases; and employment of nuclear, biological, and chemical weapons (to include
weapons of mass destruction) that have the potential to affect the short- or long-term
health (including psychological impact) of personnel. (JP 4-02)

heavy antitank weapon — A weapon capable of operating from ground or vehicle, used to
defeat armor and other material targets.

heavy artillery — See field artillery.

heavy drop — A system of delivery of heavy supplies and equipment by parachute.

heavy-lift cargo — 1. Any single cargo lift, weighing over 5 long tons, and to be handled
aboard ship. 2. In Marine Corps usage, individual units of cargo that exceed 800
pounds in weight or 100 cubic feet in volume.

heavy-lift ship — (*) A ship specially designed and capable of loading and unloading
heavy and bulky items. It has booms of sufficient capacity to accommodate a single lift
of 100 tons.

height delay — See altitude delay.

height hole — See altitude hole.

height of burst — (*) The vertical distance from the Earth’s surface or target to the point of
burst. Also called HOB. See also optimum height of burst; safe burst height; types
of burst.

helicopter direction center — (*) In amphibious operations, the primary direct control
agency for the helicopter group/unit commander operating under the overall control of
the tactical air control center. Also called HDC. (JP 3-04)

helicopter landing zone — A specified ground area for landing assault helicopters to
embark or disembark troops and/or cargo. A landing zone may contain one or more
landing sites. Also called HLZ.

helicopter support team — (*) A task organization formed and equipped for employment
in a landing zone to facilitate the landing and movement of helicopter-borne troops,
equipment, and supplies, and to evacuate selected casualties and enemy prisoners of
war. Also called HST.

helicopter transport area — Areas to the seaward and on the flanks of the outer transport
and landing ship areas, but preferably inside the area screen, used for launching and/or
recovering helicopters. (JP 3-02)

helicopter wave — See wave.

helipad — (*) A prepared area designated and used for takeoff and landing of helicopters.
(Includes touchdown or hover point.)

heliport — (*) A facility designated for operating, basing, servicing, and maintaining

herbicide — A chemical compound that will kill or damage plants. (JP 3-11)

HERO SAFE ordnance — Any ordnance item that is percussion initiated, sufficiently
shielded or otherwise so protected that all electro-explosive devices contained by the
item are immune to adverse effects (safety or reliability) when the item is employed in
its expected radio frequency environments, provided that the general hazards of
electromagnetic radiation to ordnance requirements defined in the hazards from
electromagnetic radiation manual are observed. See also electromagnetic radiation;
hazards of electromagnetic radiation to ordnance; HERO SUSCEPTIBLE
ordnance; HERO UNSAFE ordnance; ordnance. (JP 3-04)

HERO SUSCEPTIBLE ordnance — Any ordnance item containing electro-explosive
devices proven by test or analysis to be adversely affected by radio frequency energy to
the point that the safety and/or reliability of the system is in jeopardy when the system
is employed in its expected radio frequency environment. See also electromagnetic
radiation; hazards of electromagnetic radiation to ordnance; HERO SAFE
ordnance; HERO UNSAFE ordnance; ordnance. (JP 3-04)

HERO UNSAFE ordnance — Any ordnance item containing electro-explosive devices
that has not been classified as HERO SAFE or HERO SUSCEPTIBLE ordnance as a
result of a hazards of electromagnetic radiation to ordnance (HERO) analysis or test is
considered HERO UNSAFE ordnance. Additionally, any ordnance item containing
electro-explosive devices (including those previously classified as HERO SAFE or
HERO SUSCEPTIBLE ordnance) that has its internal wiring exposed; when tests are
being conducted on that item that result in additional electrical connections to the item;
when electro-explosive devices having exposed wire leads are present and handled or
loaded in any but the tested condition; when the item is being assembled or
disassembled; or when such ordnance items are damaged causing exposure of internal
wiring or components or destroying engineered HERO protective devices. See also
electromagnetic radiation; hazards of electromagnetic radiation to ordnance;
HERO SAFE ordnance; HERO SUSCEPTIBLE ordnance; ordnance. (JP 3-04)

Hertz-Horn — See chemical horn.

H-hour — See times.

high airburst — The fallout safe height of burst for a nuclear weapon that increases
damage to or casualties on soft targets, or reduces induced radiation contamination at
actual ground zero. See also types of burst.

high altitude bombing — Horizontal bombing with the height of release over 15,000 feet.

high altitude burst — (*) The explosion of a nuclear weapon which takes place at a height
in excess of 100,000 feet (30,000 meters). Also called HAB. See also types of burst.

high-altitude low-opening parachute technique — A method of delivering personnel,
equipment, or supplies from airlift aircraft that must fly at altitudes above the threat
umbrella. Also called HALO. (JP 3-17)

high-altitude missile engagement zone — See weapon engagement zone. (JP 3-52)

high angle — (*) In artillery and naval gunfire support, an order or request to obtain high
angle fire.

high angle fire — (*) Fire delivered at angles of elevation greater than the elevation that
corresponds to the maximum range of the gun and ammunition concerned; fire, the
range of which decreases as the angle of elevation is increased.

high-density airspace control zone — Airspace designated in an airspace control plan or
airspace control order, in which there is a concentrated employment of numerous and
varied weapons and airspace users. A high-density airspace control zone has defined
dimensions which usually coincide with geographical features or navigational aids.
Access to a high-density airspace control zone is normally controlled by the maneuver
commander. The maneuver commander can also direct a more restrictive weapons
status within the high-density airspace control zone. Also called HIDACZ. (JP 3-52)

high explosive cargo — Cargo such as artillery ammunition, bombs, depth charges,
demolition material, rockets, and missiles.

high oblique — See oblique air photograph.

high-payoff target — A target whose loss to the enemy will significantly contribute to the
success of the friendly course of action. High-payoff targets are those high-value
targets that must be acquired and successfully attacked for the success of the friendly
commander’s mission. Also called HPT. See also high-value target; target.
(JP 3-60)

high-payoff target list — A prioritized list of high-payoff targets by phase of the joint
operation. Also called HPTL. See also high-payoff target; target. (JP 3-60)

high-risk personnel — Personnel who, by their grade, assignment, symbolic value, or
relative isolation, are likely to be attractive or accessible terrorist targets. Also called
HRP. See also antiterrorism. (JP 3-07.2)

high value airborne asset protection — A defensive counterair mission that defends
airborne national assets which are so important that the loss of even one could seriously
impact US warfighting capabilities or provide the enemy with significant propaganda
value. Examples of high value airborne assets are Airborne Warning and Control
System, Rivet Joint, Joint Surveillance and Target Attack Radar System, and Compass
Call. Also called HVAA protection. See also defensive counterair. (JP 3-01)

high value asset control items — Items of supply identified for intensive management
control under approved inventory management techniques designed to maintain an
optimum inventory level of high investment items. Also called hi-value asset control

high-value target — A target the enemy commander requires for the successful completion
of the mission. The loss of high-value targets would be expected to seriously degrade
important enemy functions throughout the friendly commander’s area of interest. Also
called HVT. See also high-payoff target; target. (JP 3-09)

high velocity drop — (*) A drop procedure in which the drop velocity is greater than 30
feet per second (low velocity drop) and lower than free drop velocity. See also
airdrop. (JP 3-17)

high-water mark — Properly, a mark left on a beach by wave wash at the preceding high
water. It does not necessarily correspond to the high-water line. Because it can be
determined by simple observation, it is frequently used in place of the high-water line,
which can be determined only by a survey. When so used, it is called the high-water
line. (JP 3-10)

hill shading — (*) A method of representing relief on a map by depicting the shadows that
would be cast by high ground if light were shining from a certain direction.

hinterland, far — That region surrounding a beach or terminal operation to the extent that
it has characteristics that affect the operation — normally within 100 miles. (JP 4-01.6)

hinterland, near — The area of land within an operational area of a specific beach or
terminal operation — usually within 5 miles. (JP 4-01.6)

hi-value asset control item — See high value asset control items.

hoist — (*) In helicopters, the mechanism by which external loads may be raised or
lowered vertically.

hold — (*) 1. A cargo stowage compartment aboard ship. 2. To maintain or retain
possession of by force, as a position or an area. 3. In an attack, to exert sufficient
pressure to prevent movement or redisposition of enemy forces. 4. As applied to air
traffic, to keep an aircraft within a specified space or location which is identified by
visual or other means in accordance with Air Traffic Control instructions. See also fix.

holding anchorage — (*) An anchorage where ships may lie: a. if the assembly or
working anchorage, or port, to which they have been assigned is full; b. when delayed
by enemy threats or other factors from proceeding immediately on their next voyage; c.
when dispersed from a port to avoid the effects of a nuclear attack. See also assembly
anchorage; emergency anchorage; working anchorage.

holding attack — An attack designed to hold the enemy in position, to deceive the enemy
as to where the main attack is being made, to prevent the enemy from reinforcing the
elements opposing the main attack, and/or to cause the enemy to commit the reserves
prematurely at an indecisive location.

holding point — (*) A geographically or electronically defined location used in stationing
aircraft in flight in a predetermined pattern in accordance with air traffic control
clearance. See also orbit point.

holding position — (*) A specified location on the airfield, close to the active runway and
identified by visual means, at which the position of a taxiing aircraft is maintained in
accordance with air traffic control instructions.

hollow charge — (*) A shaped charge producing a deep cylindrical hole of relatively small
diameter in the direction of its axis of rotation.

homeland — The physical region that includes the continental United States, Alaska,
Hawaii, United States possessions and territories, and surrounding territorial waters and
airspace. (JP 3-28)

homeland defense — The protection of United States sovereignty, territory, domestic
population, and critical defense infrastructure against external threats and aggression or
other threats as directed by the President. Also called HD. (JP 3-27)

homeland security — A concerted national effort to prevent terrorist attacks within the
United States; reduce America’s vulnerability to terrorism, major disasters, and other
emergencies; and minimize the damage and recover from attacks, major disasters, and
other emergencies that occur. Also called HS. (JP 3-28)

home recovery mission profile — A mission profile that involves the recovery of an
aircraft at its permanent or temporarily assigned operating base.

home station — The permanent location of active duty units and Reserve Component units
(e.g., location of armory or reserve center). See also active duty; Reserve
Components. (JP 4-05)

homing — (*) The technique whereby a mobile station directs itself, or is directed, towards
a source of primary or reflected energy, or to a specified point. (JP 3-50)

homing guidance — A system by which a missile or torpedo steers itself towards a target
by means of a self-contained mechanism which is activated by some distinguishing
characteristics of the target. See also active homing guidance; passive homing
guidance; semi-active homing guidance.

homing mine — (*) In naval mine warfare, a mine fitted with propulsion equipment which
homes on to a target. See also mine.

horizon — In general, the apparent or visible junction of the Earth and sky, as seen from
any specific position. Also called the apparent, visible, or local horizon. A
horizontal plane passing through a point of vision or perspective center. The apparent
or visible horizon approximates the true horizon only when the point of vision is very
close to sea level.

horizontal action mine — (*) In land mine warfare, a mine designed to produce a
destructive effect in a plane approximately parallel to the ground.

horizontal error — (*) The error in range, deflection, or in radius, which a weapon may be
expected to exceed as often as not. Horizontal error of weapons making a nearly
vertical approach to the target is described in terms of circular error probable.
Horizontal error of weapons producing elliptical dispersion pattern is expressed in
terms of probable error. See also circular error probable; delivery error; deviation;
dispersion error.

horizontal loading — (*) Loading of items of like character in horizontal layers
throughout the holds of a ship. See also loading.

horizontal situation display — (*) An electronically generated display on which
navigation information and stored mission and procedural data can be presented. Radar
information and television picture can also be displayed either as a map overlay or as a
separate image. See also head-up display.

horizontal situation indicator — (*) An instrument which may display bearing and
distance to a navigation aid, magnetic heading, track/course and track/course deviation.

horizontal stowage — The lateral distribution of unit equipment or categories of supplies
so that they can be unloaded simultaneously from two or more holds. (JP 3-02.2)

horn — (*) In naval mine warfare, a projection from the mine shell of some contact mines
which, when broken or bent by contact, causes the mine to fire.

hospital — A medical treatment facility capable of providing inpatient care. It is
appropriately staffed and equipped to provide diagnostic and therapeutic services, as
well as the necessary supporting services required to perform its assigned mission and
functions. A hospital may, in addition, discharge the functions of a clinic.

hostage — A person held as a pledge that certain terms or agreements will be kept. (The
taking of hostages is forbidden under the Geneva Conventions, 1949.)

hostage rescue — A personnel recovery method used to recover isolated personnel who are
specifically designated as hostages. Also called HR. (JP 3-50)

host country — A nation which permits, either by written agreement or official invitation,
government representatives and/or agencies of another nation to operate, under
specified conditions, within its borders. (JP 2-01.2)

hostile — In combat and combat support operations, an identity applied to a track declared
to belong to any opposing nation, party, group, or entity, which by virtue of its behavior
or information collected on it such as characteristics, origin, or nationality contributes
to the threat to friendly forces. See also neutral; suspect; unknown.

hostile act — An attack or other use of force against the US, US forces, or other designated
persons or property. It also includes force used directly to preclude or impede the
mission and/or duties of US forces, including the recovery of US personnel or vital US
Government property. (JP 3-28)

hostile casualty — A person who is the victim of a terrorist activity or who becomes a
casualty “in action.” “In action” characterizes the casualty as having been the direct
result of hostile action, sustained in combat or relating thereto, or sustained going to or
returning from a combat mission provided that the occurrence was directly related to
hostile action. Included are persons killed or wounded mistakenly or accidentally by
friendly fire directed at a hostile force or what is thought to be a hostile force.
However, not to be considered as sustained in action and not to be interpreted as hostile
casualties are injuries or death due to the elements, self-inflicted wounds, combat
fatigue, and except in unusual cases, wounds or death inflicted by a friendly force while
the individual is in an absent-without-leave, deserter, or dropped-from-rolls status or is
voluntarily absent from a place of duty. See also casualty; casualty type; nonhostile

hostile environment — Operational environment in which hostile forces have control as
well as the intent and capability to effectively oppose or react to the operations a unit
intends to conduct. (JP 3-0)

hostile force — Any civilian, paramilitary, or military force or terrorist(s), with or without
national designation, that have committed a hostile act, exhibited hostile intent, or have
been declared hostile by appropriate US authority.

hostile intent — The threat of imminent use of force by a foreign force, terrorist(s), or
organization against the United States and US national interests, US forces and, in
certain circumstances, US nationals, their property, US commercial assets, and other
designated non-US forces, foreign nationals, and their property. When hostile intent is
present, the right exists to use proportional force, including armed force, in self-defense
by all necessary means available to deter or neutralize the potential attacker or, if
necessary, to destroy the threat. A determination that hostile intent exists and requires
the use of proportional force in self-defense must be based on evidence that an attack is
imminent. Evidence necessary to determine hostile intent will vary depending on the
state of international and regional political tension, military preparations, intelligence,
and indications and warning information.

hostile track — See hostile.

host nation — A nation which receives the forces and/or supplies of allied nations and/or
NATO organizations to be located on, to operate in, or to transit through its territory.
Also called HN. (JP 3-57)

host-nation support — Civil and/or military assistance rendered by a nation to foreign
forces within its territory during peacetime, crises or emergencies, or war based on
agreements mutually concluded between nations. Also called HNS. See also host
nation. (JP 4-0)

host-nation support agreement — Basic agreement normally concluded at government-togovernment
or government- to-combatant commander level. These agreements may
include general agreements, umbrella agreements, and memoranda of understanding.
See also host nation; host-nation support. (JP 3-35)

hot photo interpretation report — A preliminary unformatted report of significant
information from tactical reconnaissance imagery dispatched prior to compilation of
the initial photo interpretation report. It should pertain to a single objective, event, or
activity of significant interest to justify immediate reporting. Also called

hot pursuit — Pursuit commenced within the territory, internal waters, the archipelagic
waters, the territorial sea, or territorial airspace of the pursuing state and continued
without interruption beyond the territory, territorial sea, or airspace. Hot pursuit also
exists if pursuit commences within the contiguous or exclusive economic zones or on
the continental shelf of the pursuing state, continues without interruption, and is
undertaken based on a violation of the rights for the protection of which the zone was
established. The right of hot pursuit ceases as soon as the ship or hostile force pursued
enters the territory or territorial sea of its own state or of a third state. This definition
does not imply that force may or may not be used in connection with hot pursuit.
NOTE: This term applies only to law enforcement activities.

hot spot — (*) Region in a contaminated area in which the level of radioactive
contamination is considerably greater than in neighboring regions in the area.

hovering — (*) A self-sustaining maneuver whereby a fixed, or nearly fixed, position is
maintained relative to a spot on the surface of the Earth or underwater. (JP 3-04)

hovering ceiling — (*) The highest altitude at which the helicopter is capable of hovering
in standard atmosphere. It is usually stated in two figures: hovering in ground effect
and hovering out of ground effect.

howitzer — 1. A cannon that combines certain characteristics of guns and mortars. The
howitzer delivers projectiles with medium velocities, either by low or high trajectories.
2. Normally a cannon with a tube length of 20 to 30 calibers; however, the tube length
can exceed 30 calibers and still be considered a howitzer when the high angle fire
zoning solution permits range overlap between charges. See also gun; mortar.

hub — An organization that sorts and distributes inbound cargo from wholesale supply
sources (airlifted, sealifted, and ground transportable) and/or from within the theater.
See also hub and spoke distribution; spoke. (JP 4-01.4)

hub and spoke distribution — A physical distribution system developed and modeled on
industry standards to provide cargo management for a theater. It is based on a “hub”
moving cargo to and between several “spokes”. It is designed to increase transportation
efficiencies and in-transit visibility and reduce order ship time. See also distribution;
distribution system; hub; in-transit visibility; spoke. (JP 4-01.4)

human factors — The psychological, cultural, behavioral, and other human attributes that
influence decision-making, the flow of information, and the interpretation of
information by individuals or groups. (JP 2-0)

human intelligence — (*) A category of intelligence derived from information collected
and provided by human sources. Also called HUMINT. See also human resources
intelligence. (JP 2-01.2)

humanitarian and civic assistance — Assistance to the local populace provided by
predominantly US forces in conjunction with military operations and exercises. This
assistance is specifically authorized by Title 10, United States Code, section 401 and
funded under separate authorities. Also called HCA. See also foreign humanitarian
assistance. (JP 3-29)

humanitarian assistance — Programs conducted to relieve or reduce the results of natural
or manmade disasters or other endemic conditions such as human pain, disease, hunger,
or privation that might present a serious threat to life or that can result in great damage
to or loss of property. Humanitarian assistance provided by US forces is limited in
scope and duration. The assistance provided is designed to supplement or complement
the efforts of the host nation civil authorities or agencies that may have the primary
responsibility for providing humanitarian assistance. Also called HA. (JP 3-57)

humanitarian assistance coordination center — A temporary center established by a
geographic combatant commander to assist with interagency coordination and
planning. A humanitarian assistance coordination center operates during the early
planning and coordination stages of foreign humanitarian assistance operations by
providing the link between the geographic combatant commander and other United
States Government agencies, nongovernmental organizations, and international and
regional organizations at the strategic level. Also called HACC. See also foreign
humanitarian assistance; interagency coordination. (JP 3-29)

humanitarian demining assistance — The activities related to the furnishing of education,
training, and technical assistance with respect to the detection and clearance of land
mines and other explosive remnants of war. (JP 3-29)

humanitarian mine action — Activities that strive to reduce the social, economic, and
environmental impact of land mines, unexploded ordnance and small arms ammunition
- also characterized as explosive remnants of war. (JP 3-15)

humanitarian operations center — An international and interagency body that coordinates
the overall relief strategy and unity of effort among all participants in a large foreign
humanitarian assistance operation. It normally is established under the direction of the
government of the affected country or the United Nations, or a US Government agency
during a US unilateral operation. Because the humanitarian operations center operates
at the national level, it will normally consist of senior representatives from the affected
country, assisting countries, the United Nations, nongovernmental organizations,
intergovernmental organizations, intergovernmental organizations, and other major
organizations involved in the operation. Also called HOC. See also operation. (JP 3-

human resources intelligence — The intelligence derived from the intelligence collection
discipline that uses human beings as both sources and collectors, and where the human
being is the primary collection instrument. Also called HUMINT.

hung ordnance — Those weapons or stores on an aircraft that the pilot has attempted to
drop or fire but could not because of a malfunction of the weapon, rack or launcher, or
aircraft release and control system. (JP 3-04)

hunter track — (*) In naval mine warfare, the track to be followed by the hunter (or
sweeper) to ensure that the hunting (or sweeping) gear passes over the lap track.

hydrogen bomb — See thermonuclear weapon.

hydrographic chart — (*) A nautical chart showing depths of water, nature of bottom,
contours of bottom and coastline, and tides and currents in a given sea or sea and land

hydrographic reconnaissance — Reconnaissance of an area of water to determine depths,
beach gradients, the nature of the bottom, and the location of coral reefs, rocks, shoals,
and manmade obstacles.

hyperbaric chamber — (*) A chamber used to induce an increase in ambient pressure as
would occur in descending below sea level, in a water or air environment. It is the only
type of chamber suitable for use in the treatment of decompression sickness in flying or
diving. Also called compression chamber; diving chamber; recompression

hyperbolic navigation system — (*) A radio navigation system which enables the position
of an aircraft equipped with a suitable receiver to be fixed by two or more intersecting
hyperbolic position lines. The system employs either a time difference measurement of
pulse transmissions or a phase difference measurement of phase-locked continuous
wave transmissions. See also loran.

hypergolic fuel — (*) Fuel which will spontaneously ignite with an oxidizer, such as
aniline with fuming nitric acid. It is used as the propulsion agent in certain missile

hypersonic — (*) Of or pertaining to speeds equal to, or in excess of, five times the speed
of sound. See also speed of sound.

hyperspectral imagery — Term used to describe the imagery derived from subdividing the
electromagnetic spectrum into very narrow bandwidths. These narrow bandwidths may
be combined with or subtracted from each other in various ways to form images useful
in precise terrain or target analysis. Also called HSI.

hyperstereoscopy — (*) Stereoscopic viewing in which the relief effect is noticeably
exaggerated, caused by the extension of the camera base. Also called exaggerated

hypobaric chamber — (*) A chamber used to induce a decrease in ambient pressure as
would occur in ascending to altitude. This type of chamber is primarily used for
training and experimental purposes. Also called altitude chamber; decompression

hypsometric tinting — (*) A method of showing relief on maps and charts by coloring in
different shades those parts which lie between selected levels. Also called altitude
tint; elevation tint; layer tint.



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