Scanner

In the context of general computing, a scanner is a device which analyzes a physical image (such as a photograph, printed text, or handwriting) and converts it to a digital image.

This can then be edited in a graphics application, or uploaded to a website (such as Wikipedia).

There is also another type of scanner that is used generally for recieving broadcasts above 30Mhz. They are illegal in some states and countries.

See also:

• MRI scanner
• CAT scan
• Scanning

Scanning

In telecommunication, the term scanning has the following meanings:

1. In telecommunications systems, examination of traffic activity to determine whether further processing is required.

Note: Scanning is usually performed periodically.

2. In television, facsimile, and picture transmission, the process of successively analyzing the colors and densities of the object according to a predetermined pattern.

3. The process of tuning a device through a predetermined range of frequencies in prescribed increments and at prescribed times.

Note: Scanning may be performed at regular or random increments and intervals.

4. In radar and radio direction-finding[?], the slewing[?] of an antenna or radiation pattern for the purpose of probing in a different direction.

Note 1: In radar, scanning may be mechanical, using a rotary microwave joint to feed the antenna, or electronic, using a phased array of radiators, the radiated pattern (beam) of which depends on the relative phases of the signals fed to the individual radiators.

Note 2: In civilian air traffic control radar, scanning usually implies continuous rotation of the antenna or beam about a vertical axis. In military radars, scanning may occur about other than a vertical axis, and may not encompass a full 360°.

Scanning is also a term for the medical technique for body imaging[?].

Scan

In telecommunication, the term scan has the following meanings:

1. To examine sequentially, part by part.

2. To examine every reference in every entry in a file routinely as part of a retrieval scheme.

3. In radar, one complete rotation of the interrogating antenna.

4. In SONAR, to search 360° or a specific search sector by the use of phased array of transducers.

5. To sweep, i.e., rotate, a beam about a point or about an axis.

Source: from Federal Standard 1037C in support of MIL-STD-188