computer science

NinJo

NinJo is a computer 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 NinJo rather than just read about it. In short: NinJo is a meteorological software system. It is a community project of the German Weather Service, the Meteorological Service of Canada, the Danish Meteorological Institute, MeteoSwiss, and the German Bundeswehr.

Key takeaways

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

Reference excerpt

NinJo is a meteorological software system. It is a community project of the German Weather Service, the Meteorological Service of Canada, the Danish Meteorological Institute, MeteoSwiss, and the German Bundeswehr. It consists of modules for monitoring weather events, editing point forecasts and viewing meteorological data. An additional batch component is able to render graphical products off-line, these may, for example, be visualized by a web service. Essentially it is a client—server system an implemented fully with the programming language Java. NinJo was initiated by the German Weather Service (Deutscher Wetterdienst, DWD) and the German army (Bundeswehr Geo Information Service, BGIS) in 2000. Since 2006, NinJo has been used operationally. NinJo is licensed for weather services, organisations and universities not taking part in the development consortium.

Description NinJo is a client-server system with interactive displays on the client side fed by batch applications implemented on the server. The system is programmed entirely in Java and can easily be extended by further layers and applications according to user-specific requirements. The workstation fed by the servers can be installed on different operating systems (e.g. Unix, Linux and Microsoft Windows), avoiding importing the source code onto the specific operating system. The NinJo Server imports a variety of meteorological data, such as METAR reports, weather radar and weather satellite images and numerical weather prediction (NWP) outputs, through dedicated file handling programs, and make them accessible to the client displays. The client is a NinJo workstation which presents data in separate layers. Users can add as many layers to a NinJo scene as they want with all layers show time-synchronised data for the same map area. The layers show geo-referenced data, not fix images, so the screen display is always done directly from the data and interactive probing using the mouse is giving the values of the original data, not a scale extracted one. The data are stored in native format, rather than stored in a common internal format, avoiding degradation in zooms and always keeping the full details and resolution of the original data. The layers are independent, can be added and removed from the scenes separately, and be set visible or invisible. Layers can be arranged in any order the users want enabling them to arrange all data types according to their specific needs. Scenes can be set for:

Visualisation of weather products Monitoring the state of data input Production of weather warnings Interactive editing of texts Configuration of NinJo batch products Different tools are available for enhancing or interrogating the displays. For example, it is possible to do vertical cross-sections in a layered scene, extracting the vertical structure of NWP or radars data.

References

External links "NinJo web page on the German Weather Service (DWD) website" (in German). "Research with NinJo examples on the German Weather Service (DWD)". "Java Advanced Imaging in Action (NinJo)". Archived from the original on 2007-03-11.

Illustrations

Worked examples

Example 1 — a first encounter with NinJo

Start with the simplest possible case. Write down what NinJo claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer 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 NinJo 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 NinJo 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 NinJo

In research: NinJo appears in computer 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 NinJo 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: NinJo is common in secondary-school and first-year university syllabi. It links to neighbouring topics Bundeswehr, Graphic software in meteorology, Meteorological Service of Canada, so understanding it makes those chapters shorter.
In everyday life: Look for NinJo 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 NinJo in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NinJo 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 NinJo out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NinJo in simple terms?

Why does NinJo matter?

Because it connects several computer 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 NinJo?

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 NinJo.