• Learn about Minerals.
  
  
• Learn about Igneous Rocks.
  
  
• Learn about Metamorphic Rocks.
  
  Go to the Cal-Poly's ALERT HomePage.

Play Geography Games Online. A nice way to teach/learn geography.

National Geographic Web Site. The web site is almost as good as the magazine.

Virtual Travel. Go anywhere in the world and never leave your computer!

Nova Online. A game to teach you how GPS works.

WEB SITES

Trimble GPS Tutorial
The one everyone visits to learn about GPS.

U.S. Coast Guard GPS Site
The official government GPS site..

GIS Data Depot
The site for all GIS maps and map data.

Maps, Compasses and GPS 101
A very nice, simple tutorial covering maps and GPS technology.

NASA-JPL GPS Website
A word from our sponsor.

INTERESTING BOOKS

Letham, Lawrence, 1998; GPS Made Easy : Using Global Positioning Systems in the Outdoors , The best-selling GPS book for the outdoorsman.

Kaplan, Elliot D., 1996; Understanding Gps : Principles and Applications , A definitive reference on GPS, costly and technical.

Monmonier, Mark and De Blij, H.J., 1996; How to Lie With Maps , A humorous, but clever introduction to map basics

Trying to figure out where you are and where you're going is probably one of man's oldest pastimes. Navigation and positioning are crucial to so many activities and yet the process has always been quite cumbersome.Over the years all kinds of technologies have tried to simplify the task but every one has had some disadvantage. Finally, the U.S. Department of Defense decided that the military had to have a super precise form of worldwide positioning. And fortunately they had the kind of money ($12 billion!) it took to build something really good. The result is the Global Positioning System, a system that's changed navigation forever. (Trimble Navigation Limited)

Before we get too involved in the basics of GPS we need to address a couple of topics. The first one involves the acquisition of a few items (if you are broke you might as well stop reading here!). None are prohibitively expensive (in fact one is free!), but you are going to be set back a few hundred dollars. You will need each of the following:

• GPS Receiver - GPS receivers range in price from sub $100 models to high end units costing over $10,000. For this exercise you will need a model that allows you to download data to your PC. The two most popular brands are Garmin and Magellan, although several others are available. Until recently, Garmin pretty much owned the market. Their GPS12 series were/are very popular. Magellan recently released their 300 series of receivers with many new features and these have become best sellers. While a very low end (sub $100) receiver might be nice for the occasional backpacker, the limited flexibility of the unit is not desirable for most users. I have found the Magellan 315 ($150 street) or Garmin GPS12 ($200 street) will do just about everything you would want. Then why the $10,000+ receivers? They are more accurate, but also more bulky. How much more accurate? Well, the answer is that as of May, 2000 not a heck of a lot. You see, the DOD who owns the satellite network used to add noise to the signal to deliberately degrade its accuracy (they were worried about terrorists etc). So the high end units included sophisticated ways of filtering out that noise to improve accuracy. As of May, satellite signal degradation was discontinued. That means that $100-200 handheld unit is accurate to about 15-30 feet, while a $10,000 unit may be accurate to 5-10 feet. Not really worth the extra cost is it? The only ones now purchasing the high end units are surveyors who need the most accurate data possible. What am I saying? No matter what your salesman tells you, buy a $150-200 unit and it will do most everything you want. Avoid the lesser known brands because you will have a more difficult time finding compatible software.

   

• GPS Software - GPS software is another necessity. It allows the GPS user to download data in the form of waypoints and routes to the PC. It has the additional advantage in that it allows the PC user to load base maps upon which the GPS data can be plotted. The software typically is called GIS (Geographic Information Systems) software. It ranges in price from high-end packages like ArcView and MapInfo costing hundreds or even thousands of dollars to low end programs that are often free. The axiom here is "you get what you pay for". The high end packages do everything the professional would ever want, but come with a downside, they are memory hogs and have very steep learning curves. The freeware often has very limited functionality, meaning it may only do one thing well or work with a single brand/model of GPS receiver. After much Internet searching I can upon an Australian software program called OziExplorer. It works well with all popular GPS receivers, is easy to use and inexpensive ($75 for registration). There is even a trial freeware demo available although the registered full package is necessary for this exercise. The downside is OziExplorer only works on the PC. If you have a MAC or are using an oddball GPS receiver that is not supported by OziExplorer I suggest you talk to your salesperson about a compatible software package. The good news is that most of the full featured GPS/GIS software will do what you need for this exercise. For my purposes I will assume you have OziExplorer and will walk you through the exercise on that basis.

   

• Digital Topographic Map- The last part is the best, you will need a digital version of the U.S.G.S. Topographic Map for your local school or any landmark you choose as a base for the GPS exercise. For my purpose, I chose Butterfield Ranch Elementary School, in Chino Hills, CA (my son graduated from there last year!). The good part is that the digital maps are free! You will need to go to a place called GIS Data Depot. And don't worry I will walk you through finding the proper topographic map for your school.

We also need to discuss the goals of this exercise. It is designed to teach you and your students the following (REMEMBER: the goals are flexible so feel free to modify them to suit your classroom):

• fundamental map reading skills including latitude and longitude determinations, digital map co-ordinate systems and finding yourself on the globe
• map registration and plotting routes and waypoints on digital maps
• determining distances to known landmarks
• converting between metric and American units of distance
• simple trigonometry (i.e. finding the third side of a triangle)

We are now ready to tackle a few fundamentals. The first topic we will delve into is maps and mapping. You will learn that locating yourself accurately on a 3-D body like our planet is not as simple as pulling out our AAA map! Second we need to discuss GPS and how it works. Both of our discussions are necessarily brief, you are encouraged to surf the Web for more comprehensive resources if your interest is piqued

• Learn About Mapping and Map Datums
• The Global Positioning System and How It Works

Now you are ready to use your GPS receiver and learn about the digital world of mapping. The following exercise is only designed as an example, you will need to modify it for your particular school. Have Fun on your walk and with OziExplorer!