Subject Area Lessons

## #1616. Tracking Satellites Using Latitude and Longitude

Science, level: Senior
Posted Mon Mar 6 11:11:50 PST 2000 by Rick Dees (dees@mcn.net).
Huntley Project High School, Worden, Montana, USA
Materials Required: Computer with Internet access, world map
Activity Time: 1 hour
Concepts Taught: Latitude, Longitude, Map Scale, Dimensional Analysis

Tracking Satellites Using Latitude and Longitude

Background: Whether you know it or not, there are several thousand pieces of man-made space debris orbiting the earth as you read this. Many of these pieces are left-over parts from rockets used long ago. Many of them are satellites that are currently used to:

a) map the surface of the earth
b) take pictures of storm systems that help us predict the weather
c) record temperatures of the ocean waters
d) assist in telecommunications so that you can watch MTV or make overseas phone calls
e) take pictures of planets, stars and galaxies far, far away

There are four basic types of satellite orbits but each satellite just does one of them. The four types are:

1. Polar orbiting satellites - These satellites orbit from the north pole to the south pole and back to the north pole, over and over again. As the earth spins beneath the satellite, the satellite takes pictures of a narrow path of the earth underneath it.

2. Equatorial orbiting satellites - These satellites orbit around the equator. They
rise above it, dip below it then back again.

3. Inclined orbiting satellites - These satellites orbit at an angle as they go around the earth.

4. Geostationary orbiting satellites - These satellites sit high above the earth (about 35,000 km) and stay above the same place all of the time. These are the type of orbits that weather satellites use.

Objective: In this activity, you will plot the path of several satellites using their latitude and longitude.

Procedure:

1. Go to the website below.
http://www.fourmilab.ch/earthview/satellite.html

2. Once you get to this website, you'll see a window containing the names of over two dozen satellites that are currently orbiting the earth. On the right side of this widow, you'll see a scroll bar. Scroll down the list and you'll see dozens of different satellites.

3. Select one of the satellites and write it's name in the blank below.

_____________________

4. Now click on the button at the bottom of this window that says View Earth From Satellite.

5. This page shows you what the satellite is currently is "seeing". If the picture is black, that's because the satellite is on the night side of the earth.
On top of the picture, you are given the distance above the earth that the satellite is currently orbiting at. You are also given the latitude and longitude of the satellite. Notice that the latitude and longitude are given in degrees and minutes.

6. Using the world map supplied by your teacher, plot the latitude and longitude of each satellite. Use a different colored pen for each one, or you can use a different symbol for each one.

7. Check the coordinates of your satellite every five minutes and plot the new positions of the world map.

8. At the end of the hour, determine which of the four types of satellite paths your satellites are following.

Teachers: A good alternative site is:

http://liftoff.msfc.nasa.gov/realtime/JTrack/Spacecraft.html

This site is a little more graphic and may be more enjoyable to the users.

Another activity that you can do with this once you get satellite paths charted, is to determine the velocity of the satellite(s). This activity incorporates the use of map scales and dimensional analysis. Using your ruler, measure the distance between two plotted points and convert that distance to miles (or km). Divide this distance by the time (five minutes if you are taking readings every five minutes) and convert to miles per hour (or km per hour).
Having only one computer in my classroom, I hooked the computer up to a projector and projected the image onto an overhead screen so all of the students could see it. Since the calculations were a little difficult for my students, I walked them through the procedure and then let them do the rest on their own. They loved it!