Gps and Gis in Military

Table of Contents

Global Positioning Systems 3

GPS works like this: 3

Technical Description 4

Applications of Global Positioning Systems 5

GPS Military Perspective 5

Facility Management ÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽK.6

TrackingÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽK6

Bomb Missile GuidanceÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽK7

Rescue...............................................................................................................................................8

GPS for GIS 9

Geographic Information Systems 10

What is a GIS? 10

How does a GIS work? 10

Data capture 11

Data integration . 11

Data modeling. 13

GIS Military Perspective 13

Defense Estate ManagementÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽK13

TerrainÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽK.13 EvaluationÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽK..............14

Naval operationÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽK..14

Air operationsÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽKÐŽK.15

Acknowledgements

I am especially grateful to our instructor Mr. Theuri, for providing a basis in which we could research and write our paper. IÐŽ¦m also grateful to the following who tested this work as it was being written. Their comments and suggestions have been invaluable:

Elkanah Walela

Abigael Irangi

Sheila Khayanga

Lenah Ashibende

We thank LF Courier who supervised the printing and binding of this text. Barbara Khakasa designed the imaginative artwork on the cover page, together with the line drawings.

Finally I would like to thank my own fellow students, for whom and with whom the text was presented to. Their candid evaluation of our work, and their refusal to accept anything less than perfect clarity in explanation have been driving forces behind the creation of my topic, GPS & GIS Military Perspective.

Global Positioning Systems

The Global Positioning System is a constellation of 24 well-spaced satellites that orbit the Earth and make it possible for people with ground receivers to pinpoint their geographic location. The location accuracy is anywhere from 1 to 100 meters depending on the type of equipment used. The GPS is owned and operated by the U.S. Department of Defense, but is available for general use around the world.

GPS works like this:

„X 24 GPS satellites, 21 active, 3 spare are in orbit at 20,200 kilometers above the Earth. The satellites are spaced so that from any point on Earth, at least four satellites will be above the horizon

„X Each satellite contains a computer, an atomic clock, and a radio. With an understanding of its own orbit and the clock, the satellite continually broadcasts its changing position and time. Once a day, each satellite checks its own sense of time and position with a ground station and makes any minor correction

„X On the ground, any GPS receiver contains a computer that calculates its own position by getting time signals from three of the four satellites, using a process called trilateration, which is similar to triangulation. The result is provided in the form of a geographic position, longitude and latitude for most receivers, within 100 meters

„X If the receiver is also equipped with a display screen that shows a map, the position can be shown on the map

„X If a fourth satellite can be received, the receiver/computer can figure out the altitude as well as the geographic position

„X If you are moving, your receiver may also be able to calculate your speed and direction of travel and give you estimated times of arrival to specified destinations

„X Some specialized GPS receivers can also store data for use in Geographic Information Systems (GIS) and map making.

Technical Description

Navigation Signals

GPS satellites broadcast three different types of data in the primary navigation signals. The first is the almanac which sends coarse time information with second precision along with status information about the satellites. The second is the ephemeris, which contains orbital information that allows the receiver to calculate the position of the satellite at any point in time.

The satellites also broadcast two forms of accurate clock information, the Coarse Acquisition code, or C/A, and the precise code, or P-code. The former is normally used for most civilian navigation. It consists of a 1,023 bit long pseudo-random code broadcast at 1.023 MHz, repeating every millisecond. Each satellite sends a distinct C/A code, which allows them to be identified. The P-code is a similar code broadcast at 10.23 MHz, but it repeats only once per week.

Calculating Positions

GPS allows receivers to accurately calculate their distance from the GPS satellites. The receivers do this by measuring the time delay between when the satellite sent the signal and the local time when the signal was received. This delay, multiplied by the speed of light, gives the distance to that satellite.