Radar and Electronic Warfare - EEs Talk Tech Electrical Engineering Podcast #22

Radar basics & the world of aerospace electronic warfare
Click to subscribe! ► http://bit.ly/Scopes_Sub ◄
Links & agenda ↓↓↓

Get updates for each new electrical engineering podcast at:
https://eestalktech.com
https://eestalktech.com/radar-and-ele...

Keysight RF on Facebook:
  / keysightrf  

Keysight bench on Facebook:
  / keysightbench  

Mirrors on the moon:
https://en.wikipedia.org/wiki/Lunar_L...

Radar calibration sphere in low earth orbit:
http://www.dtic.mil/docs/citations/AD... (for full paper, click the "full text" link)

Agenda:

00:20
automotive adaptive cruise control works really well!

1:00
the history of radar - the first radar used an oscilloscope (WWII).
http://www.pearl-harbor.com/georgeell...

1:45
Early warning radar was the first application

2:00
The "carrots are good for your eyesight" rumor was a British intelligence misinformation campaign

2:58
The British's "chain home radar system" pointed off the coast to the western front. They wanted early warning radar because of limited defensive capabilities. By knowing what was coming, they could strategically allocate defenses

3:45
Radar was originally used for defense

3:50
How does radar work? Send out a pulse modulated on a carrier frequency. If the pulse gets reflected, you can do some math and determine how far away the reflecting object is

4:30
Typically, you use a specific frequency. For long range radar, like search and early warning radar, use a lower frequency

5:15
What does a modern radar system look like?

Setup depends on the application. Early warning systems can be a radome anchored on an old oil rig

6:25
How does radar detect and resolve something so far away? It depends on the frequencies and processing techniques used

6:40
There are some radar techniques you can use, like bouncing off of the ocean, the earth or the troposphere.

7:15
Radar also has navigational benefits. For example, detecting wind shear flying into the Breckenridge airport. A change in medium is measurable by radar

8:10
Radars are installed on missiles for last-minute corrections

8:35
The ultimate goal of radar is to detect objects and figure out range, elevation (azimuth), velocity, etc.

Different target sizes and ranges require different pulse widths, different frequencies, etc.

To detect azimuth, you know what direction your radar is pointing.

To detect velocity with radar you can measure Doppler shift.

10:30
Radar cross section analysis gives information about what is being painted

11:00
There are spherical polygons in space used for radar calibration. You can send pulses to the sphere and measure what you get back

11:40
There are reflectors on the moon - you can use laser telescopes and measure the reflection

12:30 NASA put reflectors in low earth orbit

12:58
So, you send a pulse and get a return reflection, but there was a scattering effect. There are libraries for what different object's return pulse for looks like, which helps you identify what you are looking at

14:00 Radar counter intelligence and electronic warfare techniques

First, you have to know you are being painted by radar. Military jets have a number of antennas all around it. And, you generally know what radars are being used in a theater of operation. So, there will be a warning that will let you know you are being painted by a certain type of radar.

15:30
Get Daniel on a fighter jet!

16:05
How do you keep your radar from being detected and interfered with?

Radar frequency hopping is a technique where you change the frequency from pulse to pulse.

Radar frequency modulation changes the modulation from pulse to pulse - phase shifts, amplitude changes, frequency chirps, etc.

Frequency hopping and modulation helps you avoid detection, get better performance, and reduce susceptibility to radar jamming.

If you know how your radar responds to different signals, you have a lot of flexibility in what signals you can use

How do you spoof a radar? You have to know what signals you are being painted with and how they will act over time. You can then send out pulses advanced or lagging in time or with different Doppler shifts to feed misinformation to the receiver.

You can also drown out incident pulses so that your pulses get read instead of the reflections coming off of you.

You must have an intimate knowledge of the radar you're trying to defeat, a good system to respond quickly, and good intel that something is actually happening.

Radar peak energies range from kilowatts to Megawatts.

21:10
A new US Navy ship has a hull design that scatters so well it has to turn on a beacon for safety.

https://www.forbes.com/sites/niallmcc...

22:00
Radar shows up in a lot more places than you'd expect

Radar stands for "radio detection and ranging"