ECE 5320 Mechatronics Assignment 1: Literature on Sensors and Actuators

1. Topic: Radar as a Sensor Prepared by: McLain L. Cox Dept. of Electrical and Computer Engineering Utah State University 9 March 2005 ECE 5320 MechatronicsAssignment 1: Literature on Sensors and Actuators

2. Outline • Reference List • To Explore Further • How Radar works • Uses of Radar • How to combat Radar

3. References • www.howstuffworks.com • atcsl.tripod.com/radar_theory.htm • www.nasa.gov • www.milavia.net/aircraft/f-22/gallery/f-22_18.htm • hitachi-chem.co.jp/english/products/arp/images/ • aval-technology.com/contractor_images/ • radar.wrh.noaa.gov/radar/latest/DS.p19r0/ si.kmtx.shtml • weathersavvy.com/Doppler1.htm • www.radar-detectors.com/radar-detector-recommendations.asp • danbricklin.com/log/2002_04_11.htm • southport.jpl.nasa.gov/ • pantransit.reptiles.org/images/1996-07-28/atlantis-mir-dock.jpg • bullnet.co.uk/auctions/product_16710.htm • Optics fourth edition, Eugene Hecht

4. To Explore Further • Radar is widely used in weather. Searches produce mass amounts of weather radar. Use specifics if looking for a certain kind of radar use. Military use is a little harder to come by. I think some of it is still classified.

5. What is Radar • Radar is the transmission of radio waves and the detection of their reflection.

6. How does radar work? • Radar uses two things that we are very familiar with to accomplish its tasks: echo and doppler shift. An echo works by reflectng sound off a surface, just like the picture. Radar works by bouncing radio waves off a surface, and measuring the time it takes to receive the reflection of the waves, the distance to the object can be calculated. • Source www.howstuffworks.com

7. More on how radar works • Doppler shift refers to the velocity of the object to which the radar waves have reached. When the radio waves returns to the antenna, there is a change in the wavelength of that wave. This helps determine the speed of the object. The formula looks like this:

8. How is Radar a sensor • Used to detect surrounding objects • Airplane navigation • Automobile obstacle avoidance • Ship navigation • Used to detect weather patterns • Used to determine the speed of an object • Police radar • Used to map something

9. Radar for Detection • Some radar is ground based, and consists of large antennas. • Some are placed on ships to determine surroundings, such as weather and obstacles • Source http://atcsl.tripod.com/radar_theory.htm

10. Radar in Airplanes • UAVs use radar to avoid obstacles in path • Source www.nasa.gov

11. Radar in Airplanes • Used in fighter jets to identify friend or foe, determine the distance to the oncoming or fleeing plane, and determine relative position in formation. • Source www.milavia.net/aircraft/f-22/gallery/f-22_18.htm

12. Radar in Automobiles • Obstacle avoidance systems • Source http://hitachi-chem.co.jp/english/products/arp/images/

13. Radar on Ships • Used to view surrounding surface ships • Used to view incoming air traffic • Source http://naval-technology.com/contractor_images/

14. Radar used for weather • Radar was discovered that it could be used for weather by accident. During WWII, blips were seen on the screen while attempting to track airplanes. These blips were discovered to be rain. Thus radar became a tool for weather forcasting.

15. Radar used for weather • Radar can detect moisture in the air, meteorologists have discovered how to use this to their advantage in forcasting weather. • Source http://radar.wrh.noaa.gov/radar/latest/DS.p19r0/ si.kmtx.shtml

16. Radar used for weather • Most weather radar systems are referred to as Doppler Radar • This is due to their ability to overcome the Doppler Effect. • Source http://weathersavvy.com/Doppler1.htm

17. Radar used by the Police • Radar guns used to determine the speed of passing vehicles. • Source www.radar-detectors.com/radar-detector-recommendations.asp

18. Radar at sporting events • Sometimes the speed of other objects is desired. Objects such as baseballs. • Source danbricklin.com/log/2002_04_11.htm

19. Radar to map something • Space Shuttles and satellites use radar to map the surface of the celestial body they are orbiting. • Source: http://southport.jpl.nasa.gov/

20. Radar to map something • The imaging of surfaces can show details of the surfaces in this sort of fashion

21. Radar to map something • Radar is also used to dock two space vehicles together. It can map the docking ports and give accurate details to the mating of the two vehicles. • Source http://pantransit.reptiles.org/images/1996-07-28/atlantis-mir-dock.jpg

22. Radar Detection • Radar is very useful in many applications, but in some applications, people would prefer to interfere with the signals. There are ways of detecting radar, and then confusing the signal to be used to their advantage.

23. Radar Detection • Radar use can be detected by some instruments. Some people like to travel fast and hide from the radar guns of police. They use this dectector to determine the use of radar guns. • Source http://bullnet.co.uk/auctions/product_16710.htm

24. Radar Detection for Military • The French fighter Rafale uses active cancellation to confound radar detection. It sends out a signal that's one half a wavelength out-of-phase with the radar wave it reflects. The reflected and emitted waves cancel in the direction of the enemy receiver. • Source: Optics fourth edition, Eugene Hecht