Re: Could this device be built?

The TRR was slaved in azimuth and elevation to the TTR.

The TTR had the required hardware to track in azimuth and elevation.

When jammed, the TTR tracked the jamming source.

The TRR provided only range information.

The TTR was X band.

The TRR was Ku band and frequency agile to get around the jamming.

Jammers have to behave somewhat suicidally. I've tracked real-world jamming sources and they are very easy to track because they put out one heck of a signal. In Vietnam, our jamming planes were called "Wild Weasels" and were often short-lived.

In Hawk the TRR was called the ROR, range-only-radar. But the frequencies and the function were the same. In Hawk, range information could be optional, since the missile homed. In Nike, range information was critical, because the missile was a remote controlled airplane of sorts.

Hawk was later augmented with optical tracking based on a telescope, a TV camera, and sometime after that, an IR imager.

No, the Wild Weasels were recce. The EWO (Electronic Warfare Officer), ususally the GIB (Guy In Back), had a spectrum-analyzer display, to sniff out the jammers (and maybe even comm.). I don't know exactly what they did with the info, other than evasive maneuvers, but it gave a pretty good idea of the radar environment they were flying into.

I'm sure they carried their own jammers, but so did all of the other fighters/bombers.

Cheers! Rich

At the time, the Bad Guys only had a limited number of standard radar platforms. So with a spiral antenna and a spectrum analyzer, you could pretty quickly tell what was in the neighborhood from the emission frequency and the rough envelope. And with a directional antenna and a little hunting around, you could pretty quickly localize the direction of the source. So with a pretty limited toolkit, you could tell what the bad guys were (ie. targetting radar, sky search, airborne radar) and where they were. Likewise you could very easily tell a legitimate radar system from a jammer from the spectrum, and the jamming platforms were fairly standardized.

Doing this while being shot at is left as an exercise to the student and may not be as easy as identifing spectral envelopes in an air-conditioned laboratory.

--scott

Frequency agile Ku band transmission? What kind of tube did they use for that? Wondering why the Ku band could not just take a handoff and do the tracking on its own, must not have been a stable track. What kind of cheap ill-begotten antenna gets you less angular resolution at Ku band than X-band?

Klystrons and Magnetrons can be mechanically tuned over a limited range. Making the receivers track the transmitters is a bigger problem.

The jamming equipment I worked against was pretty limited - it seemed to only jam one band at a time. After all, it was in a fighter/bomber (F4) not a B-52.

As long as my HIPIR didn't try to obtain ranging information, the jammer usualy just enhanced my radar's target tracking accuracy. Seriously, a target could be kinda marginal for tracking due to extreme range, but when he turned on his jammer the tracking often tightened right up. His counter for that was to try to AM his signal close to the rotational speed of the rotating scanner, but as a rule that was not very effective. It is possible that his jammer was optimized for a scanner that ran faster or slower.

Since jamming usually *enhanced* HIPIR tracking, making the ROR track for itself would like going backwards.

Furthermore, once you had even a guess at the target's range, a homing missle had a good chance of getting to the target. Range info was most important for knowing when the target was in range. Range did go into the lead angle calculations for optimizing the intercept, but it was a smaller part of the solution.

A really small one, or one with a rough surface, but that wasn't the problem.

Ku band is appreciably more sensitive to problems with rain and snow, not that X band isn't also affected by them. But weather is less of a problem in the X band.

Look at how satellite TV suffers with heavy weather.

It used magnetrons, dual, independant receivers and transmitters and a panoramic display.

It takes a quadurature feed to get angular error information and the TRR didn't have that and didn't need it as you got all the angular information needed from the TTR.

ALQ-71? ALQ-72? ALQ-87? QRC-119? ;-)

Cheers! Rich

Fred Bloggs snipped-for-privacy@nospam.com posted to sci.electronics.design:

Sure, chirp radar is over 40 years old. TWT comes to mind. They may have had a problem figuring out CSRO for Ku band at the time. A bent horn?

How about voltage tunable magnetrons? I had some low power ones that served as local oscillators; I don't remember high power output versions however. Anyone?

Regards,

Michael

The ALT-6B and ALT-22 used mechanically tuned magnetrons, that used hydraulics to move "tuning pins" in and out of the cavities.

For voltage control, you want a BWO, Backward-Wave Oscillator. They're kind of like a morphodite of a magnetron and TWT. ;-)

Cheers! Rich

Morphodite? I thought that was what you are.

You thinking? Highly unlikely.

-- Service to my country? Been there, Done that, and I've got my DD214 to prove it. Member of DAV #85.

Michael A. Terrell Central Florida

It's a made-up word; it can mean anything you want it to. ;-)

And it's not really the right word to use for the BWO - maybe "melange" of a maggie and TWT would be more elegant. ;-)

Cheers! Rich