- B-21 Raider
- US next-generation stealth bomber replacing the B-2 Spirit. Designed for penetrating advanced integrated air defenses to deliver conventional and nuclear payloads. Nuclear-certified, optionally unmanned.
Show the visualisation
- 3D modelTry it: Aerospace Defense Industry GuideTry it: Tdl GuideTry it: Defense Breakthrough Guide+1 more
- B-dot Controller
- A simple spacecraft detumble algorithm that commands magnetorquers to produce a magnetic moment opposing the change in measured magnetic field, reducing angular rates without attitude knowledge.
Show the visualisation
- 3D model
- BAC
- Budget at Completion — the total approved budget for the work.
Show the visualisation
- BACN — Battlefield Airborne Communications Node
- An airborne communications relay carried by the E-11A aircraft. Bridges incompatible data links (IFDL to Link 16, SADL to Link 16) by receiving on one waveform and retransmitting on another.
Show the visualisation
- 3D modelTry it: Tdl Guide
- BAFO — Best and Final Offer
- The final revised proposal submitted by offerors during a competitive procurement after discussions or negotiations. Represents each offeror last opportunity to improve their bid.
Show the visualisation
- DiagramTry it: Purchase Method Advisor
- Bandwidth Allocation
- The administrative assignment of spectrum to a specific service, user, or system. Static allocations through ITU-R Radio Regulations; dynamic spectrum access (DSA) and CBRS adapt allocations in seconds based on local conditions.
Show the visualisation
- DiagramTry it: Ssa Guide
- BARCAP — Barrier Combat Air Patrol
- A fighter patrol established along a specific line or area to intercept hostile aircraft before they reach a defended area. Creates a barrier between the threat axis and protected assets.
Show the visualisation
- 3D model
- BAS — Battalion Aid Station
- The Role 1 medical facility of a battalion providing initial treatment and casualty stabilization.
Show the visualisation
- BATNA — Best Alternative to a Negotiated Agreement
- The course of action a party will take if current negotiations fail. Defining BATNA clarifies when to walk away and sets the floor for acceptable outcomes. Introduced in Getting to Yes (Fisher & Ury, 1981).
Show the visualisation
- DiagramTry it: Stakeholder Negotiation Sim
- Battery (Spacecraft)
- Secondary (rechargeable) energy storage providing power during eclipse periods and peak demand. Modern spacecraft use lithium-ion cells. Depth of discharge is a key life-limiting parameter.
Show the visualisation
- 3D model
- Battle Drill
- A collective task trained to automatic execution without deliberate decision-making. Battle drills are a subset of Procedures — they become drills only after sufficient repetition achieves reflexive response. Examples: React to Contact, Break Contact, Enter and Clear a Room.
Show the visualisation
- DiagramTry it: Ttps Guide
- BCH — Bose–Chaudhuri–Hocquenghem code
- A cyclic error-correcting code family able to correct multiple random bit errors.
Show the visualisation
- BCR — Battery Charge Regulator
- The power electronics that control charging of spacecraft batteries from the solar array.
Show the visualisation
- BCT — Brigade Combat Team
- The US Army basic deployable unit of action containing 3,000-5,000 soldiers with organic infantry/armor, artillery, engineer, signal, and logistics. Three types: IBCT (infantry), SBCT (Stryker), ABCT (armored).
Show the visualisation
- 3D modelTry it: Orbat GuideTry it: Ttps GuideTry it: Multi Domain Spectrum Planner+1 more
- BDA — Battle Damage Assessment
- Post-strike evaluation of the degree of damage inflicted on a target. Categories: physical, functional, and system-level damage. Drives restrike decisions.
Show the visualisation
- 2D animationTry it: Multiint Fusion GuideTry it: Joint Ops GuideTry it: Defense Missions Guide+1 more
- BDR — Battery Discharge Regulator
- The power electronics that condition battery output to the bus during eclipse or peak loads.
Show the visualisation
- Beam Steering
- Directing an antenna's main beam without physically moving the antenna, by adjusting per-element phase (or amplitude) in a phased array. Enables AESA radar to track multiple targets simultaneously and switch modes at electronic speed.
Show the visualisation
- 3D modelTry it: Radar SystemsTry it: Defense Fundamentals Guide
- Beamwidth
- Angular width of an antenna main beam, typically measured at the -3dB (half-power) points. Determines angular resolution. Narrower beamwidth requires larger aperture.
Show the visualisation
- 3D modelTry it: Rf Coverage PlannerTry it: Radar SystemsTry it: Defense Spectrum Map+1 more
- BeiDou — BeiDou Navigation Satellite System
- China's global navigation satellite system, completed 2020 with 35 operational satellites. Provides worldwide PNT with regional augmentation, SMS messaging, and a military signal in addition to civilian services.
Show the visualisation
- 3D modelTry it: Space Fundamentals GuideTry it: Pnt GuideTry it: Space Mission Evolution+1 more
- BER — Bit Error Rate
- The ratio of erroneously received bits to the total number of bits transmitted. A fundamental measure of digital communication link quality, typically plotted against Eb/No.
Show the visualisation
- 2D animationTry it: Waveform GeneratorTry it: Tdl GuideTry it: Rf Encoding Modulation+1 more
- Beta Angle — Solar Beta Angle (β)
- Angle between the orbital plane and the Sun direction. Determines eclipse duration and thermal environment.
Show the visualisation
- BFSK — Binary Frequency-Shift Keying
- An FSK scheme carrying one bit per symbol using two discrete carrier frequencies.
Show the visualisation
- BFT — Blue Force Tracking
- A GPS-enabled system that tracks and displays the location of friendly forces on a shared map.
Show the visualisation
- BGP — Border Gateway Protocol
- The path-vector routing protocol that exchanges reachability between autonomous systems on the Internet.
Show the visualisation
- Bi-Elliptic Transfer
- A three-burn orbital transfer via a very high intermediate apogee. More delta-v efficient than Hohmann when the radius ratio is greater than ~11.9, at the cost of significantly longer transfer time.
Show the visualisation
- 3D model
- Biosurveillance
- Continuous monitoring and analysis of health data, environmental samples, and intelligence indicators to detect biological threats early. Integrates clinical data, air sampling networks, agricultural monitoring, and intelligence for anomalous disease pattern detection.
Show the visualisation
- 2D animationTry it: Homeland Security FundamentalsTry it: Cbrn Defense Guide
- BIT — Built-In Test
- A self-test capability embedded in a system that automatically detects and reports faults.
Show the visualisation
- BITE — Built-In Test Equipment
- The onboard hardware and software that performs a system’s built-in self-diagnostics.
Show the visualisation
- BJT — Bipolar Junction Transistor
- A semiconductor device sensitive to displacement damage (NIEL) from proton and neutron radiation. Current gain (hFE) degrades over mission lifetime in the space radiation environment.
Show the visualisation
- DiagramTry it: Space Environment Effects Guide
- BlackSky
- Commercial high-revisit EO operator. ~20 sub-metre optical satellites with 90-min revisit at mid-latitudes. Strong defence-customer focus.
Show the visualisation
- 3D modelTry it: Constellation GuideTry it: Space Spectrum MapTry it: Aerospace Defense Industry Guide+1 more
- BLE — Bluetooth Low Energy
- A low-power wireless personal-area technology for short-range device communication.
Show the visualisation
- BLOS — Beyond Line-of-Sight
- Radio communications that reach beyond the visible horizon via relay, satellite, or ionospheric skip. Essential for command and control of deployed forces and UAVs operating beyond direct line-of-sight of the controller.
Show the visualisation
- DiagramTry it: Tdl GuideTry it: Defense Spectrum MapTry it: Multi Domain Spectrum Planner+1 more
- BLS — Batch Least Squares
- The classical orbit determination technique: collect a batch of observations, linearise about a reference state, and solve for state corrections that minimise the residual sum of squares. Produces a deterministic best-fit state and covariance.
Show the visualisation
- Diagram
- BLT — Battalion Landing Team
- The ground-combat element of a Marine expeditionary unit built around a reinforced infantry battalion.
Show the visualisation
- Blue Cell
- The friendly-force team in a wargame, developing courses of action, rehearsing decisions, and responding to red moves. Distinct from the white cell (neutral umpire).
Show the visualisation
- DiagramTry it: Wargaming Methodology Guide
- Blue Team
- Defenders responsible for detecting, containing, and eradicating adversary activity. Work in a SOC, operate SIEM tooling, and collaborate with incident response.
Show the visualisation
- DiagramTry it: Cyber Warfare Guide
- BLUF — Bottom Line Up Front
- A communication style that states the most important conclusion or recommendation at the beginning.
Show the visualisation
- BMD — Ballistic Missile Defense
- Systems designed to detect, track, and intercept ballistic missiles during boost, midcourse, or terminal phase. Includes sensors, command and control, and kinetic/directed-energy interceptors.
Show the visualisation
- 3D modelTry it: Defense Fundamentals GuideTry it: Defense Spectrum MapTry it: Aerospace Defense Industry Guide+1 more
- BOA — Basic Ordering Agreement
- A pre-negotiated instrument establishing terms, conditions, and pricing for future orders. Not a contract itself — each delivery order placed against it becomes a separate contract. Streamlines repetitive procurement of spare parts, services, or sustainment.
Show the visualisation
- 2D animation
- Body Frame
- A spacecraft-fixed coordinate frame, conventionally with axes aligned to the principal moments of inertia or to payload boresights. Attitude is the rotation that maps inertial frame to body frame; control torques are commanded in body frame.
Show the visualisation
- 3D modelTry it: Adcs 3d SimulatorTry it: Eo Satellite OpsTry it: Defense Coordinate Systems+1 more
- BOL — Beginning of Life
- Spacecraft performance at the start of operations (e.g. solar array power).
Show the visualisation
- BOL/EOL — Beginning of Life / End of Life
- Refers to the spacecraft power subsystem's performance at launch (BOL) versus after degradation from radiation and thermal cycling (EOL). Solar array sizing must account for EOL power requirements.
Show the visualisation
- 3D model
- BOM — Bill of Materials
- A structured list of the parts, components, and quantities needed to build or repair a product.
Show the visualisation
- Boost Phase
- The powered ascent of a ballistic missile from launch through burn-out. Short duration (60–300 s) and bright infrared signature make it the ideal intercept window — but requires interceptors close to the launch point.
Show the visualisation
- DiagramTry it: Defense Fundamentals GuideTry it: Ballistic Missile Defense
- Boost-Glide Profile
- Trajectory combining rocket boost to high altitude followed by unpowered hypersonic glide. Couples the range of ballistic missiles with the cross-range maneuverability of aircraft, complicating defensive engagement.
Show the visualisation
- 2D animation
- Bow-Tie Analysis
- A risk analysis method visualising threats on the left, a top event in the centre, and consequences on the right, with preventive barriers (left) and mitigating barriers (right).
Show the visualisation
- 2D animation
- BP — Battle Position
- A defensive location oriented on an enemy avenue of approach from which a unit defends.
Show the visualisation
- BPA — Blanket Purchase Agreement
- A simplified acquisition method establishing charge accounts with qualified sources of supply. Used for repetitive purchases of supplies or services below the simplified acquisition threshold to reduce administrative costs.
Show the visualisation
- 2D animationTry it: Sar Trainer
- BPSK — Binary Phase Shift Keying
- A digital modulation scheme that encodes one bit per symbol by shifting the carrier phase by 180 degrees. Offers the best BER performance per Eb/No but lowest spectral efficiency.
Show the visualisation
- 2D animationTry it: Rf Encoding ModulationTry it: Waveform GeneratorTry it: Rf Signal Scanner Manual+1 more
- BQQ — Submarine Sonar Set
- The AN/BQQ designation series for integrated submarine sonar suites for detection and tracking.
Show the visualisation
- BQR — Submarine Passive Sonar Receiver
- The AN/BQR designation series for submarine passive sonar receivers used for silent detection.
Show the visualisation
- BQS — Submarine Active Sonar Set
- The AN/BQS designation series for submarine active sonar sets used for ranging and detection.
Show the visualisation
- BR (Breach Force) — Breach Force
- Second element of breach organisation under SOSRA. Reduces the obstacle (clears mines, breaches wire) to open lanes for the Assault Force after Support Force has suppressed and obscured.
Show the visualisation
- Diagram
- Bradley (M2/M3)
- US infantry/cavalry fighting vehicle with 25mm chain gun and TOW missile launcher. Carries infantry squad (M2) or scouts (M3). Being replaced by XM30 under the Optionally Manned Fighting Vehicle program.
Show the visualisation
- 3D model
- BRDF — Bidirectional Reflectance Distribution Function
- A function describing how a surface reflects light as a function of illumination and viewing geometry.
Show the visualisation
- Brigade
- A military formation consisting of 3,000–5,000 personnel organised under a single commander, typically combining several battalions. The basic combined-arms manoeuvre unit in most modern armies.
Show the visualisation
- DiagramTry it: Ttps GuideTry it: Orbat GuideTry it: Wargaming Methodology Guide+1 more
- BSA — Bistatic Radar
- A radar configuration in which the transmitter and receiver are separated by a significant distance.
Show the visualisation
- BSB — Brigade Support Battalion
- A battalion that provides logistics, maintenance, and medical support to a brigade combat team.
Show the visualisation
- BSP — Ballistic Missile Submarine Patrol
- A strategic deterrent patrol conducted by a ballistic-missile submarine.
Show the visualisation
- BT — Bathythermograph
- An instrument that records water temperature versus depth to support sonar-range prediction.
Show the visualisation
- BUC — Block Up Converter
- A ground terminal component that converts and amplifies the uplink signal to the transmit frequency band.
Show the visualisation
- Burn-Through Range
- The range at which a radar can overcome a standoff jammer's noise and re-detect the target. Determined by the ratio of radar power, antenna gain, and pulse integration vs jammer power and proximity.
Show the visualisation
- DiagramTry it: Ew Guide
- BVLOS — Beyond Visual Line of Sight
- UAS operations conducted beyond the pilot's direct visual range. Requires detect-and-avoid, robust C2 link, contingency procedures, and (in most jurisdictions) a specific operational waiver. Key enabler for long-range inspection, delivery, and tactical UAS missions.
Show the visualisation
- Diagram
- BVR — Beyond Visual Range
- Air combat engagement conducted at ranges beyond the pilot's visual acquisition capability (typically >10 km), employing radar-guided missiles such as AMRAAM or Meteor.
Show the visualisation
- DiagramTry it: Defense Fundamentals GuideTry it: Tdl GuideTry it: Ttps Guide+1 more
- BW — Bandwidth
- The range of frequencies a signal occupies or a system passes, which sets resolution and data-rate limits.
Show the visualisation
- BWA — Biological Warfare Agent
- A microorganism or toxin deliberately used to cause disease or death in people, animals, or plants.
Show the visualisation
Questions this page didn't answer
Send them and we will answer directly, including the ones with awkward answers.
Get in touch