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

Ғылым және технология

Radar basics & the world of aerospace electronic warfare
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Mirrors on the moon:
en.wikipedia.org/wiki/Lunar_L...
Radar calibration sphere in low earth orbit:
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).
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.
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"

Пікірлер: 34

  • @KeysightLabs
    @KeysightLabs6 жыл бұрын

    We changed our channel name! To clarify my statement about the first radar display, it appears that it was an oscilloscope and they would measure the distance between the transmitted signal pulse and the reflected pulse on the screen.

  • @yaghiyahbrenner8902

    @yaghiyahbrenner8902

    6 жыл бұрын

    Love the channel name!

  • @tommihommi1

    @tommihommi1

    6 жыл бұрын

    Keysight Labs I can confirm that this works for sonar, too. You can trigger on your sent signal and just look at the delay and signal distortion on the screen, basically did this during an internship in 9th grade in a water tank

  • @electrofun2490

    @electrofun2490

    6 жыл бұрын

    U guys are doing purely awesome stuffs

  • @NeuroMod
    @NeuroMod6 жыл бұрын

    Keep the podcast format as is.... very fun and interesting... just release them more often if you can!

  • @JuliaLing
    @JuliaLing3 жыл бұрын

    I LOVED this! And spheres for calibration. Gives a whole new meaning to "space balls." Thanks guys!

  • @huey8242
    @huey82425 жыл бұрын

    This is right up my alley. I love ECM.

  • @Richardincancale
    @Richardincancale6 жыл бұрын

    A British guy - Robert Watson Watt drove the early development of radar - he claimed to be the ‘father’ of radar. I was lucky enough to find his autobiography - signed by him - in a thrift store!

  • @davidsandell7833
    @davidsandell78334 жыл бұрын

    Radar analyst from 81-95. Good basic info. Could get much more in-depth but lots of people would be lost. Pulse Doppler is really interesting.

  • @martinsimlastik5457
    @martinsimlastik54576 жыл бұрын

    Very interesting episode!

  • @fifaham
    @fifaham3 жыл бұрын

    @10:38 there is what is called SAR (Synthetic Aperture Radars) and are used to deduce the nature of large objects by cascading the small areas of the detected object one at a time and this need faster and more processing power to concatenate various detected sections of the object into one single object.

  • @chuxxsss
    @chuxxsss6 жыл бұрын

    I love adaptive cruise. Radar is cool. Also calibration is cool, I had both qualifications.

  • @narutouchiha1946
    @narutouchiha19466 жыл бұрын

    EE student rn just listening for fun while playin some MMORPG. dope podcast i love it.

  • @KeysightLabs

    @KeysightLabs

    6 жыл бұрын

    Thanks!

  • @joanakankunda-xw7op
    @joanakankunda-xw7op Жыл бұрын

    Radars are surely cool Deeply in love with their technolOgy

  • @n3ttx580
    @n3ttx580 Жыл бұрын

    Very cool podcast, only thing that kinda messed with me was that Mike probably did not understood that the radio wave transmitted by radar is not always perpendicular to the object, and that it almost never bounces back at 90°, and also that radars have a visibility radius, rather than just a "point" view.

  • @fifaham
    @fifaham3 жыл бұрын

    @4:50 there is what is called cooperative radar detection where multiple pulses maybe used, it is sort of analogy to array antenna but not an array - also there is adaptive and dynamic detection where the single signal (Multiple pulses sent as one package - varying the pulse width to compensate for various object conditions of the object being detected) to cover up a dynamic detection zone that can not be detected by a single pulse, otherwise. There are various methods of detection and ranging that can involved more than one detection signal and more than one pulse and frequency, depending on the technology and environment used at. Also depending on how far the object to detect the interrogating pulse (with certain pulse width) may not be able to accurately detect the object because of the loss of signal power (based on trigonometry rules) so for this reason the manipulation of the pulse width maybe necessary to get a more accurate signal reflection describing the object (location in space).

  • @tarjei99
    @tarjei99Ай бұрын

    For cars, visible lasers might be better. At least for parking and anything that requires knowing how far away something is.

  • @tarjei99
    @tarjei99Ай бұрын

    Carrots were the explanation for airborne radar, not Chain Home. Chain Home were augumented by human observers.

  • @FrankEdavidson
    @FrankEdavidson6 жыл бұрын

    Professor Reginald Victor "R. V.' Jones was behind the British Home Chain. After the war Jones was Professor of Natural Philosophy at Aberdeen University and worked on improving accuracy of instruments.. Since you mention space lasers, SAR is widely used in earth observation.

  • @FrankEdavidson

    @FrankEdavidson

    6 жыл бұрын

    e.g. m.esa.int/Our_Activities/Observing_the_Earth/CryoSat/Instruments

  • @Loopei
    @Loopei6 жыл бұрын

    I am interested in the "translucent" properties at certain frequencies. As well as frequencies that are used in certain scenarios. For example, the Radome you where talking about has to have a certain Epsilon at given frequency... And the attenuation Weather or other atmospheric conditions have on the signal as discussed early in the podcast.

  • @smahax

    @smahax

    6 жыл бұрын

    Christian Wehrle , the way the Radom is manufactured has influences on the propagated signal. For example, they often build the Radom in several pieces, the junction of these pieces will have another transmission path than when you are in a none junction area.

  • @chuxxsss
    @chuxxsss6 жыл бұрын

    I remember one of my teachers gone done by the police for blowing up their radar gun. Old gun used an amplifier with the guns frequency.

  • @chuxxsss
    @chuxxsss6 жыл бұрын

    Sub mirco second pulse you need time for it to return. Use range gates.

  • @JuliaLing
    @JuliaLing3 жыл бұрын

    Radio detection and ranging. YES! lol

  • @TedKekatos
    @TedKekatos6 жыл бұрын

    I was told by my parents that WWII Radar was developed and manufactured in the Chicago area----by various companies. Primary company was ZENITH. Located on the west side of the city. See this article: www.encyclopedia.chicagohistory.org/pages/419.html

  • @Factory400
    @Factory4006 жыл бұрын

    How do you calibrate space lasers?

  • @chuxxsss

    @chuxxsss

    6 жыл бұрын

    Factory400 Very hard, you would need another satellite with a optocoupler which can pick up the lasers frequency. This is because it would be distorted if passed through the ionosphere so hard to calibrate.

  • @jafinch78

    @jafinch78

    6 жыл бұрын

    NIST has standards is my guess. For frequency calibration, I read somewhere that the SRM2035 was used in space also as an internal transmission standard. Maybe a 99% reflectance standard also. I'm not sure if 1920a was or is used in space and same goes with SRM 2036 which has the 99% reflectance standard backing. Furthermore, there are land based standards that are well disclosed from the 50's and 60's era where one is noted as used in the 30's for aircraft: www.atlasobscura.com/articles/landscapes-made-for-satellite-eyes-calibration-targets-resolution-tests-and-giant-desert-compasses

  • @Tadesan
    @Tadesan6 жыл бұрын

    Sure. Mm hmm. Yup.

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