science

Point-defence

Point-defence is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Point-defence rather than just read about it. In short: Point defence (or point defense; see spelling differences) is the defence of a single object or a limited area, e.g. a ship, building or an airfield, now usually against air attacks and guided missiles. Point defence weapons have a smaller range in contrast to area-defence systems and are placed near or on the object to be protected.

Key takeaways

Point-defence belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Point-defence to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Point-defence from memory before moving on to harder problems.

Reference excerpt

Point defence (or point defense; see spelling differences) is the defence of a single object or a limited area, e.g. a ship, building or an airfield, now usually against air attacks and guided missiles. Point defence weapons have a smaller range in contrast to area-defence systems and are placed near or on the object to be protected. Point defence may include:

Short-ranged interceptor aircraft Close-in weapon systems (CIWS) on ships, or C-RAM on land installations Directed-energy weapons (DEW), such as high-energy lasers (HEL) or microwave beams Land-based short-ranged anti-aircraft guns or surface-to-air missile systems Active protection systems on tanks or other armoured fighting vehicles Coastal artillery to protect harbours is similar conceptually, but is generally not classified as point defence. Similarly, passive systems—electronic countermeasures, decoys, chaff, flares, barrage balloons—are not considered point defence.

Examples

Aircraft Bachem Ba 349 Natter – vertical take-off rocket powered crewed interceptor (prototypes only) Convair XF-92 – Later used as testbed for later projects. F-14 ADC – Proposed interceptor for the USAF Air Defense Command. Junkers EF 009 Hubjäger – Proposed interceptor with 10 radially placed turbojet engines. Messerschmitt Me 163 Komet – World War II-era operational German rocket powered interceptor. NR-349 – Proposed Improved Manned Interceptor replacement for the F-101, F-102 and F-106.

Close-in weapons systems Goalkeeper CIWS – Gun CIWS in current service by the Dutch navy. Phalanx CIWS – 20 mm Vulcan cannon mounted on a swivelling base. Notably used on almost all major surface combatants of the US Navy. Kashtan CIWS – Gun-Missile CIWS in current service by the Russian navy. Type 730 – in current use by the Chinese Navy.

Directed-energy weapons DragonFire – UK-built high energy laser. HELIOS - US-built high energy laser

Surface-to-air missile systems RIM-116 RAM – Missile CIWS in current use by the US Navy. Barak 1 – Israeli point defence missile. VL-SRSAM – Indian point and area defence missile.

Active Protection Systems Arena APS – a Russian point defence system for individual armoured vehicles. Trophy APS - an Israeli APS in service with the IDF.

See also Index of aviation articles List of established military terms Zero-length launch List of government and military acronyms List of military tactics

References

Worked examples

Example 1 — a first encounter with Point-defence

Start with the simplest possible case. Write down what Point-defence claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Point-defence before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Point-defence ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Point-defence

In research: Point-defence appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Point-defence in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Point-defence is common in secondary-school and first-year university syllabi. It links to neighbouring topics Military science, Military stubs, so understanding it makes those chapters shorter.
In everyday life: Look for Point-defence outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Point-defence in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Point-defence means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Point-defence out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Point-defence in simple terms?

Why does Point-defence matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Point-defence?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Point-defence.