MAPS & NAVIGATION
Every time you go from one place to another, you are using some form of navigation. Turn right. Turn left. Think about how you found your way to your friend's house or to the park nearby. This is all about navigation!
While the Tire Tracks team is in Africa, they will use maps & navigation almost every time they drive in the car or go into town for a walk. One very important tool the team will use is called GPS. Do you know what GPS is and what a GPS unit looks like? Do you know that a GPS uses satellite signals to help you find your way?
You can read all about maps & navigation in this section: Understanding Maps; Compass; What is GIS?; Navigation Fun facts; Navigation terms; Why do we need a GNSS?; What is GNSS?; What is GPS?; The 3 segments of GPS; How GPS works; GPS Accuracy; GPS Uses; Why Tire Tracks needs GPS; Tips for using GPS; Helpful Links
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Ever heard of a Topographical map?
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| Part of a 7.5-minute topographic map at 1:24,000 scale |
A topographic map (topo) tells you where things are and how to get to them, whether you're hiking, biking, hunting, fishing, or just interested in the world around you. These maps describe the shape of the land.
These maps define and locate natural and manmade features like woodlands, waterways, important buildings, and bridges. They also show the distance between any two places, and the direction from one point to another.
From Near to Far: How to find Distance on a map
Maps are made to scale. This means that a unit of measurement on the map is directly related to the actual distance of that same unit on the ground. A convenient way of representing map distance is by the use of a graphic scale bar. 
Many maps have scale bars in the map margin that represent distances on the map in miles, feet, and kilometers.
COMPASS
To determine the direction, or bearing, from one point to another, you need a compass as well as a map. Most compasses are marked with the four cardinal points-north, east, south, and west.
But, some compasses are also marked with the number of 
degrees in a circle: 360: north is 0 or 360, east is 90, south is 180, and west is 270.
Both kinds are easy to use with a little practice.
Does a compass really point true North? Read more here.
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WHAT IS GIS?
A geographic information system (GIS) is a computer system capable of capturing, storing, analyzing, and displaying geographical info. A GIS might allow emergency planners to easily calculate emergency response times in the event of a natural disaster, or a GIS might be used to find wetlands that need protection from pollution.
How does a GIS work? Check it out here.
| GPS permits users to determine their 3D position, velocity, and time, 24 hours a day in all weather, anywhere in the world. | The official U.S. Department of Defense name for GPS is NAVISTAR (Navigation Satellite Timing and Ranging). |
| There are at least 4 satellites "visible" in the sky at any time, anywhere on Earth. | The DoD launched the first GPS satellite in 1978, although it wasn't fully operational until 1995. |
| Each satellite travels at about 2,000 mph and circles the globe in 11 hours and 58 minutes. This means each satellite makes 2 complete rotations every day! | Each satellite is built to last about 10 years. Replacements are constantly being built and launched into orbit. |
| The Russian GLONASS satellite weighs approximately 1300 kg, and with the solar batteries unfolded, spans 7.23 m. | Small hand-held GPS receivers can give your location within at least 15 meters or about 50 ft. |
| The satellites are solar-powered. | A full set of 24 satellites was put into orbit in 1994. |
NAVIGATION TERMS AND ABBREVIATIONS
Do you know what anti-spoofing or a Portolan chart is? Or what GLONASS stands for? Click here for a full list of navigation terms and abbreviations.
WHY DO WE NEED A GLOBAL NAVIGATION SATELLITE SYSTEM (GNSS)?
Easy answer: |
Over the last centuries, humans have used all types of techniques to figure out where they were located, how to find another place, and how to return home. 
From marking trails with piles of stones or tying red ribbons tied around trees, to using the stars to determine you location, navigation and positioning has been very important to human movement and activities.
But, this doesn't mean that these tasks have always been easy, simply or completely accurate. Remember the many stories of explorers being lost at sea or ending up in a country on the other side of the world!
Over the years, many gadgets and systems have tried to simplify the task, but they each had their downfalls. The invention of the Global Navigation Satellite System (GNSS) technology has made it one of the most accurate, easy-to use, relatively inexpensive navigation and positioning technologies to date.
WHAT IS A GLOBAL NAVIGATION SATELLITE SYSTEM (GNSS)?
Two Global Navigation Satellite System (GNSS) are currently in operation: the US Global Positioning System (GPS) and the Russian GLObal NAvigation Satellite System (GLONASS). 
A 3rd GNSS is being developed in Europe is called GALILEO, which is scheduled to begin service in 2008. Take a look at GLONASS (photo) from the Russian Ministry of Defense.
| GPS stands for Global Positioning System. |
GPS is a satellite-based navigation system that makes it possible to accurately determine precise location on earth, 24 hours a day, in all weather, anywhere in the world. The GPS system is made up of a network of 24 satellites that are nearly 11,000 miles above the earth. The satellites circle the earth every 12 hours.
GPS satellite. Courtesy of NASA
GPS consists of three segments: satellite constellation (space), ground control (ground stations monitoring satellite path), and user equipment (you and your GPS receiver.)
From Russian Ministry of Defense
Want to check out the satellite constellations, ground control and GPS receivers. Click here.
GPS receivers collect signals, containing time and distance data from satellites in view. With the satellites acting as precise reference points, the GPS receiver can measure the distance from the group of satellites in space. This allows the user to accurately identify their location anywhere on Earth.
The accuracy of a position depends on the type of GPS receiver. Many typical hand-held GPS receivers are accurate to about 10-20 meters (33 feet- 66 feet). The accuracy of GPS can be improved in a number of ways. Read more about how, here.
Today there are many uses of GPS. Boats, cars, laptop computers, farm machinery are just a few places where GPS is used. Here are a few more:
airplanes  |
construction equipment
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military equipment
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space shuttle
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Many people also use GPS for hiking, fishing, kayaking, and overlanding (like the Tire Tracks team). GPS is also used to predict weather forecasts and survey earthquakes.
We will driving in off the beaten track locations which have no signs, and sometimes no people in sight. When there are few roads, this could make navigation simple. On the other hand, you may take the wrong road and not have many options but to turn back.
There some places like the desert where we will really rely on our GPS. But, we need to make sure we have other resources as well -- the right maps (national, city, guidebook, relief), aviation charts, insight from local people and of course, gut instinct!
TIPS FOR USING YOUR GPS RECEIVER
Have a GPS receiver of your own? Want some tips on how to use it? Read about it here.
We have put together all kinds of links that you can use to research more on GPS. Click here to find out more.
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