What exactly is the difference between analogue and digital? And what is digitisation?

Question

I understand the concept, but what specific technology is used in digitisation? And how does this differ from analogue technology?

I am writing a feature about "the digital age" and digitisation, especially in reference to books and the internet, and am completely stuck on the technology side of this.

A layman's term explanation would be much appreciated...

Answer 1

In analog technology, a wave is recorded or used in its original form. So, for example, in an analog tape recorder, a signal is taken straight from the microphone and laid onto tape. The wave from the microphone is an analog wave, and therefore the wave on the tape is analog as well. That wave on the tape can be read, amplified and sent to a speaker to produce the sound.

In digital technology, the analog wave is sampled at some interval, and then turned into numbers that are stored in the digital device. On a CD, the sampling rate is 44,000 samples per second. So on a CD, there are 44,000 numbers stored per second of music. To hear the music, the numbers are turned into a voltage wave that approximates the original wave.

The two big advantages of digital technology are:

The recording does not degrade over time. As long as the numbers can be read, you will always get exactly the same wave.
Groups of numbers can often be compressed by finding patterns in them. It is also easy to use special computers called digital signal processors (DSPs) to process and modify streams of numbers.


What is digitization?

Digitization is the conversion of analog materials into digital formats for use in a computer based application.

The term digitization is a broad term used to refer to the conversion of all forms of analog materials from paper to museum artifacts. In some special cases it is even used to cover the conversion of analog music.

Document Imaging:
This is used to describe the digitization process of converting analog documents like paper into digital formats for use within an Electronic Document Management(EDM) environment.

Digital Imaging:
This is most often used in reference to digitizing collections of Museums,Libraries or Archival Institutions.

The underlining technology which makes digitization possible is the use of digitizers like scanners and digital cameras in converting the analog material.

Answer 2

Digital means that you're dealing with discrete units, while analog means you're dealing with a continuous range. Eggs, for instance, are digital. You can go out to the henhouse and get 5 eggs or 6 eggs, but you'll never come back with something inbetween. Milk, on the other hand, is analog. You might milk the cow and end up with 3.72 gallons, but it's actually an *estimate* as to how much you got, because milk is a continuous flow. One of the biggest single advantages of digital seems to be that it allows for an *exact* copy. When you make an analog copy, it's not exactly the same as the original. On the other hand, digital is "choppy". Back when you had woodburning stoves in the kitchen, the fire was on one end (typically the right) and there was a hot water reservoir at the other end, and you had a whole range of temperatures available. If your potatoes were cooking too fast, you simply would slide the skillet a little to the left. You can adjust a gas flame under a skillet, but that doesn't change the temperature the gas burns at. Turning it down produces a smaller flame of the same temperature - so the taters in the *center* of the skillet continue to burn, while the taters on the *outside* of the skillet remain raw. You can adjust an electric calrod to different temperatures, but although the switch appears to be infinitely variable, it actually only has about 100 positions at which it can be set. Vinyl records are analog, and as such, offer a richer sound than possible using the sampling techniques required to make a digital recording. Most people cannot hear the difference - but many people can. One of the reasons for switching from analog TV to digital TV is that sharper clearer broadcasts will be available using much less of the broadcast spectrum, allowing the old spectrum to be used, in part, for public safety purposes. When the first World Trade Tower collapsed, firemen and other rescue workers inside the other tower couldn't be warned to get out because collapse was imminent; the radios simply couldn't penetrate the buildings. The new spectrum being assigned for public safety radios is more capable of penetrating through buildings. In addition, other extra spectrum being freed up will be auctioned off, bringing in a lot of money to the government.

Answer 3

An analog signal produces a alternating wave pattern either alternating in amplitude or frequency. A digital signal is either a high or a low signal(commonly 5v and 0v, also known as 1's & 0's) An analog signal can be most commonly digitised by using a common analog to digital converter(A/D converter). To view the specifics of one of theses devices google search define: analog to digital converter. Digital technology is used do to its speed, capacity to do much more, and efficiency. Analog technology will still be used for many more decades however, such as in cell phone signals.

Answer 4

With music, many of the mediums involved are usually analog. The accoustics are monitored to emulate a sound to be recorded digitally. From my perspective, I'd imagine digitisation would involve the emulation and reconcstruction of analog frequencies based on digital control/properties.

Hope that helps a little.

Answer 5

There isn't a short layman's answer. But in terms of electrical waveforms think of the difference between stairs and a slide. On the stairs you can only sit a certain levels, whereas on a slide you could sit at any point (assuming you aren't sliding!). However, you could report your position acurately on the stairs, but not so easily on slide.

Answer 6

The difference is in how the information that is being sent is processed. The website below does a great job of putting this information in layman's terms...Good luck!

http://www.compukiss.com/sandyclassroom/tutorials/article273.htm

Answer 7

It's all about the waves. Analog is curved, has peeks and troffs (sp). Digital waves are squared and represent 1 and 0 as binary data.

Try these sites for help...