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Re: Radar ranging and relativity

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On 3/17/2023 10:12 PM, Richard Hertz wrote:
> On Saturday, March 18, 2023 at 12:01:26 AM UTC-3, Sylvia Else wrote:
>> On 18-Mar-23 3:45 am, Richard Hertz wrote:
>>> Why the popularized equation for radar ranging is:
>>>
>>> R = 1/2 t c₀
>>>
>>> https://www.radartutorial.eu/01.basics/Distance-determination.en.html
>> For a target, moving or otherwise, it gives the distance to the target
>> at the point where the radar signal was reflected, which happens after
>> half of the total transit time. The velocity of the target is irrelevant.
>>
>> Sylvia.
> 
> This is the basic theory for radar ranging, taught to kids in high school.
> 
> I wrote the OP in order to show the DISINFORMATION that plagues the web, being in this case from a "serious" site.
> 
> Since the 60s, radar ranging is complemented with Doppler measurement, in a single frequency swept pulse, and even
> better techniques.
> 
> Since the 90s, phased array radars are used along with computes, to acquire targets in a 3D space with resolutions of meters.
> 
> Imagine a Patriot system trying to hit a 5,000 Km/hr incoming missile (or 20,000 Km/Hr for ICBM).
> 
> The real position is tracked in real time. No turning antennae anymore.

I worked R&D on the first airborne phased array radar
(designated a decade downstream for the F-15 and F-16)
at Raytheon in 1967.

Note that most radars today (by sheer numbers) have both
the radar set as well as the target in motion. In 1967
the "computer" used hard wired logic since the programmable
chip had not yet been developed. That earliest model was
slow, cumbersome, and physically heavy.

Banerjee claims to later have worked on modifying some Russian
phased array system for his home country of India but such
knowledge as he expressed indicates he was, once again, making
false claims.

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Radar ranging and relativity Richard Hertz <hertz778@gmail.com> - 2023-03-17 09:45 -0700
  Re: Radar ranging and relativity Richard Hertz <hertz778@gmail.com> - 2023-03-17 10:21 -0700
  Re: Radar ranging and relativity "Dono." <eggy20011951@gmail.com> - 2023-03-17 19:03 -0700
    Re: Radar ranging and relativity Richard Hertz <hertz778@gmail.com> - 2023-03-17 19:51 -0700
      Cretin Richard Hertz at work "Dono." <eggy20011951@gmail.com> - 2023-03-17 21:17 -0700
  Re: Radar ranging and relativity "Dono." <eggy20011951@gmail.com> - 2023-03-17 19:48 -0700
    Re: Radar ranging and relativity whodat <whodaat@void.nowgre.com> - 2023-03-17 22:02 -0500
  Re: Radar ranging and relativity Sylvia Else <sylvia@email.invalid> - 2023-03-18 14:01 +1100
    Re: Radar ranging and relativity Richard Hertz <hertz778@gmail.com> - 2023-03-17 20:12 -0700
      Re: Radar ranging and relativity whodat <whodaat@void.nowgre.com> - 2023-03-17 22:29 -0500
        Re: Radar ranging and relativity Richard Hertz <hertz778@gmail.com> - 2023-03-18 05:44 -0700
      Re: Radar ranging and relativity Sylvia Else <sylvia@email.invalid> - 2023-03-18 15:08 +1100
      Re: Radar ranging and relativity Volney <volney@invalid.invalid> - 2023-03-19 00:31 -0400
        Re: Radar ranging and relativity whodat <whodaat@void.nowgre.com> - 2023-03-18 23:49 -0500
        Re: Radar ranging and relativity Maciej Wozniak <maluwozniak@gmail.com> - 2023-03-19 00:20 -0700
  Re: Radar ranging and relativity "mitchr...@gmail.com" <mitchrae3323@gmail.com> - 2023-03-18 12:49 -0700
    Re: Radar ranging and relativity Richard Hertz <hertz778@gmail.com> - 2023-03-18 13:33 -0700
      Re: Radar ranging and relativity "Dono." <eggy20011951@gmail.com> - 2023-03-18 16:14 -0700
  Re: Radar ranging and relativity "Paul B. Andersen" <paul.b.andersen@paulba.no> - 2023-03-21 22:24 +0100

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