How High to mount radar dome on CD25?

Thanks for the correction. I am still baffled how 28 watts in can generate 2.2kw out. Next time I find a radar engineer I am going to ask. The answer is probably over my head since I was a forestry major in college.
 
Well, radar works by sending out a pulse of radio waves called a chirp, starting to count time, and then waiting for the reflection and stopping the time count. Speed of light is 186, 000 mph, and distance is speed X time.

The energy in the pulse is 2000 watts, but average power into the radar is ~25 watts.

If you transmit continously, how do you know when to stop counting time of flight? The reflection would be continuous, and mixed up with the transmitted power. Deep space probes transmit continuously, and measure time with a long PRN code which is turned around at the spacecraft. Sending out chirps is easier.

So the difference is peak vs. average.

Sorry for the lecture, but there you go.

Boris

PS, my dad was a forestry major in college, and sometimes I wish I was.
 
Well, radar works by sending out a pulse of radio waves called a chirp, starting to count time, and then waiting for the reflection and stopping the time count. Speed of light is 186, 000 mph, and distance is speed X time.
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That would be miles per second :wink
 
Old Man thoughts..

12.36 uSec is the RadarRange Mile [2 way travel] and a 1uSec Pulse should travel 0.186 miles, or 328 yards; as I best remember..

Art
 
All I remember is 1 foot per nanosecond. Am I right?
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Boris

I'm thinking you chose the right profession. There's no way in hell I would even attempt to explain radar and certainly would't have done it a succinctly as you did. Thanks for the info. The hours/seconds thing was just a typo I'm sure. All I remembered about the speed of light is that it deals with very long distances in fractions of seconds. I googled it to make sure. :mrgreen:
As far as the nanosecond question, I have nano idea. :embarrased
 
I had a chemistry professor in college, that told me that he was stationed at an early warning radar installation in Alaska during WW2.
He said that when they got cold, that they would walk out in front of the dish to warm up. Was he just pulling my leg?
 
I once met a Navy Admiral named Grace Hopper. Retired at the age of 80 something on the deck of the USS Constitution. She used to go to lectures and hand out nanoseconds. Her nanosecond was a piece of wire just shy of 12 inches long and it represented the distance light traveled in a nanosecond. She was better known for writing the computer language Cobol.
 
Minnow-

I'm with Ken. I'm sure he was just pulling your leg.

I had a Biology Proff in college that said the medical students way back in the past would set on the X-Ray machines before going out on a date as a contraceptive measure. If anyone were that dumb, they OUGHT to be sterilized, permanently. Joe.
 
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