GPS: What's it? How Actually it Works?

GPS: What's it? How Actually it Works?

The Global Positioning System (GPS) is a space-based satellite navigation, which provides location, time information, weather reports and etc., anywhere on or near the earth. This system was originally created by the United States for military purposes, and later it was opened to civilians, who can access the system freely with a GPS receiver. The GPS program provides critical capabilities to military, civil and commercial users around the world. In addition, GPS is the backbone for modernizing the global air traffic system.

  

At least 24 GPS satellites are always in orbit around the Earth, and they’re constantly broadcasting data. The GPS project was developed in 1973 to overcome the limitations of previous navigation systems, integrating ideas from several predecessors, including a number of classified engineering design studies from the 1960s. GPS was created and realized by the U.S. Department of Defense (DoD) and was originally designed and run with 24 satellites. It became fully operational in 1994.

The satellites are arranged in orbit and four satellites are visible in the sky from any point on earth by a direct path of radio transmission. If the transmission signals are being blocked then GPS system wouldn't be functioning. The system, also, wouldn't working in a cave under a mountain or in an under ground bunker.

Nowadays, many of us using handheld devices, which use satellites to pinpoint our locations almost anywhere on the planet. But anyone ever wonder how GPS works? GPS enabled devices do not interact the satellites to transmit information; instead they only receive data, which being always transmitted from satellites. 

How GPS Determines the Location: The device that built-in GPS, for instance - a car navigation unit or a smartphone, acts only as a GPS receiver and they do not contact the satellites to determines its location; but observing the radio signals, which were being broadcast, from the satellites, all the times. So, a GPS receiver listens for signals from 4 (or more) satellites and the signals from the closer satellites will reach sooner while signals from the farther satellites will arrive later. The actual time difference is very small and could be detected by GPS receiver. The timings of signal broadcasted from the satellites and the timings of signal received on the GPS receiver are compared and estimated by the receiver for the relative distances between all the satellites. Using Trilateration, which is a process of geometry, the receiver can determining its location.

 

Alternatives to GPS: Other alternate services, for GPS, are the cell phone towers in which the towers working in the way of measuring the signal strengths between multiple towers, then the GPS receiver could be estimating the current location. Through Wi-Fi enabled devices, it could also be determined the current location. The smart phone scans the nearby wireless networks, then sending the list of wireless network names with signal strengths to Google's servers. Google uses these database then estimates the location.

Devices could also be using Wi-Fi based positioning system (WPS), where GPS is inadequate due to various causes including multipath and signal blockage. Using WPS, the device is determining its current location, capturing street views (of Google), Traffics and nearby access points such as Restaurants, Petrol Stations, ATM Centers etc., for certain locations. Google wouldn't be the only provider for WPS, but it's most familiar to us. So, WPS is convenient, especially for the indoor locations, where GPS signals couldn't reach.

In addition, GPS could be restricted or shut down during the time of war or conflict; so, every nation needs their own satellites. Russia has its own GLONASS (Global Navigation Satellite System), European Union's Galileo Positioning System, China's Compass Navigation System, and India's Indian Regional Navigational Satellite System are their own, self sufficient satellite systems.

What’s a Browser Cookie?

What’s a Browser Cookie?

Browser Cookie(s) is a small piece of information for websites that stored on your system. They contain bits of text only! The text could be an user ID, session ID or any other text. Cookies are doing an important roll while browsing and if you disabled them then you'll find yourself unable to log into websites.
 

Web pages could be configurable through cookies, as the web page having a hide link, which hides certain elements of the page, then hiding elements are saved on your system as a cookie. When loading the same page in later times, the page will be examined by the cookie and the element will be concealed automatically. 

More over, if you deleted the cookies, you'll be logged out from the web site then the web site wouldn't remember the settings you've changed. So, cookies are very essential for our browsing and your system perhaps stored a hundred or thousands of cookies!

The cookies (for Firefox) are stored in Cookies window. To get Cookies Window, right click over on Firefox window then choose View Page Info.

The Page Info window will be opened, as pictured below. From Page Info's Security tab, click View Cookies button.

Now Cookies window will be opened, as pictured below. From this window, cookies could be removed, as for Selected or All.

Cookies are helpful to the user in several ways.

• They remember the status of log-in details and identifying the user.

• They stored preferences of the web site in order to load the web pages to the previous manner.

• They allow online shopping websites to keep and provide user's personalized contents, such as for the products the user browsed, to be remembered and recommending, too, for similar products or brands.

However, cookies also doing bad rolls of tracking such as spying the users activities across the web. Advertising and tracking networks are using scripts in order to trace the users profiles then setting them as cookies in the browser. 

When visiting a website, which uses scripts from adv network and tracking network as well, then both networks could set cookies on the browser. The aim of these networks, to setting up cookies on browser, are to collect and keep users info then using them to target the user's desire. 

Through Google Ads Preferences page, the user may able to view the adv categories, which assigned by Google based websites.  

Managing Cookies is simple; they could be managed from browser's setting window.  Browser's Clear Private Data tool will also remove cookies.
  

Keep in mind that some websites wouldn't work properly if you disabled cookies for them.