Active(abbrev. ACTV). In solar-terrestrial terms, solar activity levels with at least one geophysical event or several larger radio events (10cm) per day (Class…
Active Air DefenseDirect defensive actions taken to nullify or reduce the effectiveness of hostile air action.
Active Communications Security ThreatThreats to an electronic system posed by a capability to disrupt communications or to seize control or deny positive control of electronic systems to…
Active Defense(1) The employment of limited offensive action and counterattacks to deny a contested area or position to the enemy. Also Passive Defense.
Active Defense (TBMD)Active defense protects against theater missiles by destroying them in flight. Engagement capability is required throughout all phases of the missiles…
Active Homing GuidanceGuidance system in which both the source for illuminating the target, and the receiver for detecting the illuminating energy reflected from the target is…
Active SensorOne that illuminates a target, producing return secondary radiation, which is then detected to track and/or identify the target. An example is radar.
Adaptive Defense(Also Adaptive Preferential Defense) Adaptive defense is defense that is responsive to an actual attack in that it takes advantage of the structure or…
Adaptive Flexible Defense (AFD)The ability to select and prioritize in near-real time what critical civilian and military assets and functions to defend and to efficiently employ…
Adaptive Optics (ADOPT)Optical systems, which can be modified (e.g., by controlling the shape of a mirror) to compensate for distortions.
Administrative Contracting Officer (ACO)The government contracting officer located at a contract administrative office that is assigned the responsibility for administration of Government…
Advance FundingBudget authority provided in an appropriation act that allows funds to be committed to a specific purpose (obligated) and spent during this fiscal year…
Advance ProcurementAuthority provided in an appropriations act to obligate and disburse from the succeeding years appropriation.
Advanced Concept Technology Demonstration (ACTD)An integrating effort to assemble and demonstrate a significant new military capability, based upon maturing advanced technology(s) in a real-time…
Advanced Launch System (ALS)OBSOLETE. This proposed system was to be a heavy launch vehicle and appropriate ground support facilities, which may have supported SDIO, USAF, Navy and…
Advanced Technology DemonstrationThe actual demonstration of an advanced state-of-the-art system under conditions likely to exist when in operation.
AEGISThe Navy's advanced, fast reaction, high firepower, shipboard anti-air warfare area defense system (Note: Aegis is the Greek word for "shield").
AEGIS BMDAegis Ballistic Missile Defense (Aegis BMD) Project is an element of the Ballistic Missile Defense System, and is being developed to provide a rapidly…
Aerospace Defense (AD)(1) All defensive measures designed to destroy attacking enemy aircraft, missiles, and space vehicles after they leave the Earths surface, or to nullify…
AerostatsShip- or ground-moored balloon supporting a radar antenna.
Aerothermal KillA kill in which the thermal shielding of the target RV is damaged by the defensive system. The RV is subsequently destroyed during reentry.
AFDArea Forecast Discussion - This National Weather Service product is intended to provide a well-reasoned discussion of the meteorological thinking which…