The Speed Property

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We are all familiar with a car speedometer, which tells you how fast you are driving. Although not nearly as precise, geolocationEvent has a speed property which you can use in some applications. You can imagine an application for parasailing, parachuting, or skiing, or if you prefer to remain on the ground, a measuring tool for a remotecontrolled toy.

The speed is returned in meters/second. It is a good unit for small-distance measurement. To convert to kilometers/hour, use:

event.speed * 3.6;

If you are not familiar with the metric system, convert the speed to feet/second as follows:

event.speed * 3.2808399;

To convert to miles/hour, use:

event.speed * 2.23693629; // or (event.speed*3600)/1609.344

Geolocation has inspired the development of many kinds of applications. Here are just a few:

  • Foursquare is a geo-based mobile phone application designed to enable users to share their location with friends and add comments on places visited. You earn points when you discover a new place and badges for interesting locations, and you become the mayor of a location if you are its most frequent visitor.
  • Geocaching is a worldwide high-tech treasure hunt. A geocacher places an object, also called a geocache, pinpoints its location using GPS, and shares the geocache location online. To play, you enter your postal code, choose a geocode from a list, store the coordinates on your device, and start hunting. Once you find the physical
    object, you add your name to a logbook and put the object back or replace it with another object of similar value. You can share stories and photos of your experience.
  • The Complex Network of Global Cargo Ship Movements pieced together the routes of cargo ships over the course of a year using a GPS-based vessel tracking system (http://www.wired.com/wiredscience/2010/01/global-shipping-map/). The marine traffic website displays vessels around the world in real time. The system is based on the Automatic Identification System (AIS) automated tracking system. The International Maritime Organization requires vessels to carry an AIS transponder on board, which transmits their position, speed, and course, among some other static information such as the vessel’s name, dimensions, and voyage details (for more information, go to http://www.marinetraffic.com/ais/).
  • SiliconSky GPS developed a prototype of an asthma inhaler with built-in GPS tracking capability (http://news.cnet.com/8301-17938_105-10228982-1.html). It tracks asthma inhaler use trends, including the exact time and the geographic location of inhaler users, to better monitor the health issue.
  • Nike has partnered with Apple to create NikePlus (http://judgeseyesonly.com/nikeplus_video.html), a running shoe that comes equipped with a GPS sensor and transmits your location data to your iPod.
  • To expose the technology which makes all this possible, GoSatWatch tracks and predicts visible satellites, and displays their path and their location (http://www.gosoftworks.com/GoSatWatch/GoSatWatch.html).