About Radars

Radar

Radar is an object detection system that uses electromagnetic waves to identify the range, altitude, direction, or speed of both moving and fixed objects such as aircraft, ships, motor vehicles, weather formations, and terrain. The term RADAR was coined in 1941 as an acronym for radio detection and ranging.[1][2][3][4] The term has since entered the English language as a standard word, radar, losing the capitalization. Radar was originally called RDF (Radio Direction Finder, now used as a totally different device) in the United Kingdom. It is the only word in the English language that is both an acronym and a palindrome[citation needed].
A radar system has a transmitter that emits microwaves or radio waves. These waves are in phase when emitted, and when they come into contact with an object are scattered in all directions. The signal is thus partly reflected back and it has a slight change of wavelength (and thus frequency) if the target is moving. The receiver is usually, but not always, in the same location as the transmitter. Although the signal returned is usually very weak, the signal can be amplified through use of electronic techniques in the receiver and in the antenna configuration. This enables radar to detect objects at ranges where other emissions, such as sound or visible light, would be too weak to detect. Radar uses include meteorological detection of precipitation, measuring ocean surface waves, air traffic control, police detection of speeding traffic, determining the speed of basesballs and by the military.

computer

How To Password-Protect Documents In Your Computer From Prying Eyes

There are times when we type things on our computer and save them on our computers yet we don't wish people to read whatever it is we have written and saved. For those who don't know how to protect what they have written from people who might have access to their computers other than themselves, using a password protected system to keep your documents from being accessed by other people is one thing that should be learned.Create A Password For Your PCOne of the easiest ways for you to protect your documents from other people who might use your computer from time to time would be to create a password for your User profile. Your User profile can be locked so that only you can access it and other people can use the PC from another profile that can be for common use. To password protect your User profile:1. You should first click on start then on settings and finally on Control Panel.2. From control Panel, access the User Accounts and click on your User account.3. Follow the steps for creating a password for your user account and apply it.Create A Password For Your Word DocumentsAfter you create a certain document you want to keep away the eyes of people you don't want to read it, you can always password protect it after you write it. This kind of a move password protects individual documents that you feel should be hidden from everyone else without having to create a separate user profile on your computer. Here are the steps you can use to do this:1. You first choose options from the tools menu.2. You then click on the security tab on the pop-up and you type in the password that is needed to open the document in the box provided for.3. You will then click on OK after typing in your password and you will need to re-verify this password after you click OK.4. You can then safely save the document and be secure that no one can read it without the password. You can only open this particular document after you provide the password.Protecting your documents with the use of either a user profile password or a specific document password will help ensure that whatever you wish to keep to yourself will remain safely away from people you don't want seeing your documents and what they contain.