What is GPS?

GPS stands for Global Positioning System. It is a satellite radio navigation system built by the United States Department of Defense. Research on the system began in the 60's and the first GPS satellite was launched in 1978. It took a while for the entire system to come online but finally on April 27, 1995 it became fully operational. At first, the GPS network was only for military use but in the 80's the United States government authorized the general public to make use of it too.

The GPS network is composed of:

Satellites Earth Monitoring Stations GPS receivers

What is a GPS Satellite?

There are currently 24 satellites orbiting the earth is 6 distinct trajectories. Each satellite completes two orbits around the earth each day, traveling at a speed of about 7,000 MPH. At the highest point in their orbit they are over 12,000 miles above the earth. From this height, the satellite signals can be received over a large percentage of the surface of the earth. A GPS unit works by receiving multiple satellite signals and calculating the receiver's position based on triangulation of the different signals. Accuracy is increased with each additional satellite signal that is received so the orbits of the satellites are set so that at most points on the earth there are at least 4 signals that can be received. Of course, this is in theory only since the landscape around you can block some or all of the GPS signals.

What is a GPS Earth Monitoring Station?

There are four unmanned monitoring stations in the US and one manned master station which is located in Colorado Springs, Colorado. The four unmanned stations relay position data from the satellites to the master station. The master station uses the relayed information to correct the position of the sat tiles and sends the corrected information back to the satellites. This synchronizes the data that each satellite transmits to your GPS receiver and ensures that your receiver is always working with accurate information.

What is a GPS Receiver?

GPS satellites transmit low power radio signals that can only be picked up if your GPS unit has a direct "line of sight" to the satellite. The signals can penetrate things like glass, plastic and clouds but not solid structures like buildings or rocks. A GPS unit works by triangulating your location based on the position of at least three satellites in the GPS system. It compares the time it takes to receive a signal from each of the satellites in range and calculates your location based on the data.

If you are only able to pick up three satellite signals, your GPS unit can report your location in latitude and longitude. However, when the GPS unit picks up signals from at least four satellites it also calculates your altitude. Now it can report your trip distance, distance to a destination, travel speed and even your altitude if your GPS receiver features an altimeter.

How accurate a GPS unit is depends on its ability to find and lock onto a satellite's signal. As you might expect, you get what you pay for and the more expensive GPS units are generally more accurate. The best consumer units claim accuracy to within a few feet while the older or less expensive units can be off up to 30-40 feet or more. Where you plan to use your GPS receiver could determine if it's worth shelling out the extra money for increased accuracy. If you're using your GPS unit in flatter terrain with a good open view of the sky a less expensive unit could perform nearly as well as the top of the line receiver. However, if you plan to use your receiver in dense tree cover, while hiking in ravines or narrow valleys, or among tall buildings you'll gain much better accuracy with a more higher end GPS unit.

Now you know the basics about how GPS works and can answer the question "What is GPS?".

For more information about heart rate monitors with built in GPS, check out Planet Gizmo.

Why You Must Have A Heart Rate Monitor At Home?

Heart rate Monitors are becoming the norm, and are being introduced into many homes. These monitors range anywhere from $25 to $700, depending on the functions you are looking for. You do not necessarily need to purchase the most expensive unit, because it may have features that you really do not need or might never use. If you are going to purchase one, look for one that best suits you, maybe one with a little more functionality than the basic, because you might need to use some of these other features later on down the line. Most common heart rate monitors come in the shape of wrist watches and are called Heart Rate Monitor Watches. Some of these watches offer functions such as ECG and EGG which are very useful for people suffering with heart conditions and might even be a life saving tool.

These monitors can be very useful in the case of an emergency at home when you think someone in the family may be having a heart attack and while you are awaiting the arrival of the paramedics of physician. You can check their heart rate and convey the results to the paramedics so they will be more prepared when they arrive and also this will give them a guide as what could possibly be the problem, as such they will be able to handle the situation more effectively.

Heart Rate Monitors were specifically designed for people who do very strenuous exercises, because they are able to monitor the heart rate while the actual exercise is in progress and give instant readouts on the work level of the heart. There are some that can automatically tell you when you have reached your Zone target heart rate. The ECG and EGG functions are also very useful for people suffering with heart conditions, because they can monitor their heart rates at any given time and may be alerted by the results of any possible problems they might not have been aware of if they did not have one of these monitors in their home.

What it comes down to is that every home should have a Heart Rate Monitor which will definitely be an invaluable commodity. It has already proven to be a valuable commodity in the world of runners, although some runners who may own these Monitors may not be using them to their fullest potential, but then there are others who do not own a monitor and are unaware of their benefits and how it can greatly improve their training.

About the Author

Find more ideas and resources on health related matters at http://www.questionsonhealth.net a website offering views, opinions and factual resources on topics such as affordable health insurance, healthy eating advice and even all about acid reflux.

Planet Gizmo

Here is a review of a brand new site that sells all kinds of gadgets (mostly audio related)

Planet Gizmo, just as the name entitles in an excellent source for electronic gizmos. If you have something in mind, or just want to browse the latest swag, you can check it out at www.PlanetGizmo.co.uk. As the URL suggests, they’re located in the United Kingdom, providing a reliable source for gear in central UK. Whether you’re in the market for a digital recorder, a pair of headphones, DJ equipment, speakers, mobile phone accessories, satellite, handheld GPS, a PDA or even a pink, powered ride on jeep you should check out this site.

The site’s layout is clean and simple and all products are neatly organized into an easy navigation system. For a faster find, they also have a site search so you can get the specs on your favorite electronic gizmo in a flash.

The order process is also simple and easy as can be, just add what you want to their online cart, click the checkout button and pay with any major credit card. One thing I also really like is that they accept PayPal which allows me to pay directly with my bank account. If you’re still not comfortable ordering online, no problem, just give them a call toll free at 1-800-612-2150 to order by phone. They even have a 14 day money back guarantee in case you need to return or exchange anything for any reason. Or if you’re still not entirely sure on what you want, just add it to your wish list for easy future reference.

Some other things that set Planet Gizmo apart from run of the mill sites is that they offer free shipping on all orders over £75 and they get them out fast. To be more precise, they ship same day for all orders in before 3:00pm. There’s no 48 or 72 hour delay, and they tell you if it’s in stock right on their site.

Headphones tend to be their specialty and whether you are looking for pro DJ headphones or high-end in-ear monitors, they should be your one stop headphone shop. With over 28 models to choose from, including wireless RF models, a variety of ear buds and closed back studio monitors from the industry leaders in professional audio gear including Sennheiser, a complete range of Skullcandy ‘phones,’ Stanton, Technics, AKG, Denon, PIONEER, Gemini, JBL, Rane, Klipsch. Or if you are one of the hundreds of millions of worldwide iPod users and want to replace your passé stock phones, here’s your chance to grab something a little more hi-fi.

Planet Gizmo also includes a variety of important cell phone accessories that are essential for everyday life. Need a hands free kit for your car, a sophisticated Bluetooth headset or simply a place to set your cell in your car, you check out accessories by telecom and electronics giants Nokia, Sony, Ericsson and Motorola.

Lost? Don’t know where to go? Just pick up a portable, handheld or car ready GPS navigation unit from Garmin, Navicore or Novogo at a superb price. When you combine that with free shipping, why would you shop anywhere else. These prices can’t be beat!

Or maybe you need to beef up that portable player or looking for some computer speakers that really kick? You’ve got to check out some of the booming add-on JBL or Klipsch speakers for your portable player, laptop or desktop.

If you’re looking for a great gizmo gift for a techie friend, or simple a hassle-free online ordering process then I strongly invite you to check out Planet Gizmo.