Vector Map

Key takeaways

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

Reference excerpt

The Vector Map (VMAP), also called Vector Smart Map, is a vector-based collection of geographic information system (GIS) data about Earth at various levels of detail. Level 0 (low resolution) coverage is global and entirely in the public domain. Level 1 (global coverage at medium resolution) is only partly in the public domain. There are ongoing discussions about making most of the information available in the public domain.

Description Coordinate reference system: Geographic coordinates stored in decimal degrees with southern and western hemispheres using negative values for latitude and longitude, respectively. Horizontal Datum: World Geodetic System 1984 (WGS 84). Vertical Datum: Mean Sea Level.

Thematic data layers Features and data attributes are tagged utilizing the international Feature and Attribute Coding Catalogue (FACC).

major road networks railroad networks hydrologic drainage systems utility networks (cross-country pipelines and communication lines) major airports elevation contours coastlines international boundaries populated places index of geographical names

Levels of resolution The vector map product are usually seen as being of three different types: low resolution (level 0), medium resolution (level 1) and high resolution (level 2).

Level Zero (VMAP0) Level 0 provides worldwide coverage of geo-spatial data and is equivalent to a small scale (1:1,000,000). The data are offered either on CD-ROM or as direct download, as they have been moved to the public domain. Data are structured following the Vector Product Format (VPF), compliant with standards MIL-V-89039 and MIL-STD 2407.

Data sets The entire coverage has been divided into four data sets:

North America (NOAMER) v0noa Europe and North Asia (EURNASIA) v0eur South America, Africa, and Antarctica (SOAMAFR) v0soa South Asia and Australia (SASAUS) v0sas

Level One (VMAP1) Level 1 data are equivalent to a medium scale resolution (1:250,000). Level 1 tiles follow the MIL-V-89033 standard.

Horizontal accuracy: 125–500m Vertical accuracy: 0.5–2 Contour Interval (for example: if contour interval 50 m, accuracy will be 25 to 100m)

Data sets VMAP Level 1 is divided in 234 geographical tiles. Only 57 of them are currently (2006) available for download from NGA. Among the available datasets, coverage can be found for parts of Costa Rica, Libya, United States, Mexico, Iraq, Russia, Panama, Colombia and Japan.

Level Two (VMAP2) Level 2 data are equivalent to a large scale resolution. Level 2 tiles follow the MIL-V-89032 standard.

Horizontal accuracy: 50–200m Vertical accuracy: 0.5–2 Contour Interval (for example: if contour interval 50 m, accuracy will be 25–100m)

Debate about availability of data The USA Freedom of Information Act and the Electronic Freedom of Information Act guarantee access to virtually all GIS data created by the US government. Following the trend of the United States, much of the VMAP data has been offered to the public domain. But many countries consider mapping and cartography a state monopoly; for such countries, the VMAP Level1 data are kept out of the public domain. However, some data may be commercialised by national mapping agencies, sometimes as a consequence of privatisation. Various public groups are making efforts to have all VMAP1 data moved to the public domain in accordance with FOIA. Further steps have been taken by the Free World Maps Foundation and others to have the data licensed under the GNU General Public License, while remaining copyrighted, as an alternative to the public domain. This is an ongoing debate (as of 2006).

Copyrights

VMAP0 The U.S. government has released the data into public domain, with the following conditions imposed (quotation from VMAP0 Copyright Statement):

As an agency of the United States government, NIMA makes no copyright claim under Title 17 of the United States Code with respect to any copyrightable material compiled in these products, nor requires compensation for their use. When incorporating the NIMA maps into your product, please include the following: a. "this product was developed using materials from the United States National Imagery and Mapping Agency and are reproduced with permission", b. "this product has neither been endorsed nor authorized by the United States National Imagery and Mapping Agency or the United States Department of Defense". With respect to any advertising, promoting or publicizing of this product, NIMA requires that you refrain from using the agency's name, seal, or initials.

The VMAP0 download page states:

Internal data reference to the CD-ROM being "LIMITED DISTRIBUTION" should be ignored. However, all is not quite what it seems. There is a 'readme1.txt' file located in the v0eur, v0sas, and v0soa directories. This file contains information saying that layers: Boundaries Coverage and the Reference Library, are copyrighted to the Environmental Systems Research Institute. If these copyrighted layers are not used there is no violation of any copyrights.

Tools to read and convert VMAP data VPFView (V2.1) - developed by NIMA, is available from NGA or USGS (as part of the NIMAMUSE package); this tool can render simple plots and export GIS data to other GIS file formats "OGR with OGDI driver": this free software tool can convert VMAP format to standard GIS file formats such as SHAPE, PostGIS etc.

History

1991–1993: The National Imagery and Mapping Agency (NIMA) develops the Digital Chart of the World (DCW) for the US Defense Mapping Agency (DMA) with themes including Political/Ocean Populated Places, Railroads, Roads, Utilities, Drainage, Hypsography, Land Cover, Ocean Features, Physiography, Aeronautical, Cultural Landmarks, Transportation Structure and Vegetation. One of the sources for the data was the Operational Navigation Chart that compiles military mapping from Australia, Canada, United Kingdom, and the United States. VMAP (level 0) is a slightly more detailed reiteration of the DCW. VMAP (level 1) has much higher resolution data.

2004 The National Imagery and Mapping Agency (NIMA) is renamed to National Geospatial-Intelligence Agency which will include other mapping agencies such as the Defense Mapping Agency (DMA), the Central Imagery Office (CIO) and the Defense Dissemination Program Office (DDPO). All VMAP data will subsequently be distributed through the NGA.

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Vector Map

Start with the simplest possible case. Write down what Vector Map 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 Vector Map 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 Vector Map 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 Vector Map

In research: Vector Map 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 Vector Map 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: Vector Map is common in secondary-school and first-year university syllabi. It links to neighbouring topics Geographic information systems, so understanding it makes those chapters shorter.
In everyday life: Look for Vector Map 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.

How to study Vector Map in 20 minutes

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

Frequently asked questions

What is Vector Map in simple terms?

The Vector Map (VMAP), also called Vector Smart Map, is a vector-based collection of geographic information system (GIS) data about Earth at various levels of detail. Level 0 (low resolution) coverage is global and entirely in the public domain.

Why does Vector Map 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 Vector Map?

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 Vector Map.