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To: higgmeister

A back of the envelope calculation would put the average power density in the near field of PAVE PAWS at about 200 Watts/square meter or about 275 volts RMS per meter, in the near field. (Peak power for up to 0.016 seconds is four times that.) The diffraction near field of the antenna is about 700 yards downrange. I worked with EEO fusing on spacecraft in another life. Typical activation energy is about one milliwatt-Second. One volt across one ohm for about 0.001 second. The short time constant was to achieve precision separation.

EEO are generally shielded and protected from external RF fields. Stupid shit like connecting them to large open wire loops or flying through a high power radar beam can get people killed.

Line-of-sight microwave data links are typically about 10 watts, or less. Aircraft can either obscure (shadow) the path or Doppler scatter off the aircraft can add an interfering signal that looks like high phase noise to the victim receiver.

I don’t live far from Westford, Massachusetts, home of MIT’s Haystack Radar. It’s a powerful X-Band radar (with , I believe W-Band heads, as well) that tracks and images satellites in geosynchronous orbit. Because of the high power and large aperture it would fry the electronics of anything that flew over it. It is definitely a no-fly zone. The radar operators keep in touch with Boston regional FAA just in case any aircraft strays into the exclusion area.


64 posted on 12/26/2018 3:55:45 AM PST by Lonesome in Massachussets (Schumer delenda est.)
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To: Lonesome in Massachussets
That Power difference is like Tropo Scatter versus LOS Microwave with a AN/TRC-97 Van.

The guys in ATC radar tech school said their instructors talked about frying police radar guns in speed traps near the base that happened to be close enough they could point a dish down their throats. It sounds apocryphal but as you point out power ratios make it possible I guess.

The MicroWave equipment we had at all three fixed facility sites where I was stationed, was LENKURT AN/FRA-90 Radios and 45BX3 Mux. I saw it also in the civilian world but only got up close a few times every other month, because I was always troubleshooting back in the Terminal or Junction and the Radio guys had that covered.

You may have guessed, I started in Tech Control. You real techs and engineers dig a lot deeper into the electronics but even I know that Large open wire loops can act like antennas. I couldn't count the number of times a dispatch tech or cable tech said the RFO was bridge taps or protector coils left on shared cable putting interference right into a customer's subscriber line.

65 posted on 12/26/2018 1:22:46 PM PST by higgmeister ( In the Shadow of The Big Chicken)
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