Radar Made Easy (1974) | Hacker News Reader

Radar Made Easy (1974)

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64 pointsmindcrime12 comments

Aw. That's a precious little book. Good coverage of some of the hard issues, such as receiver filters and delay lines for non-trivial radar waveforms.

Some of the big topics are skipped. The energy of a radar return decreases as the fourth power of the range, which is why you put megawatts out and get microwatts back. There's not much on electronics - nothing about how such big pulses are generated, or the clever trick which allows transmitters and receivers to share an antenna without blowing out the receiver. As is common in USSR publications of the period, examples are from US systems, so as to avoid security problems. Phased array radars are discussed, but not much is said about how the work. That was a touchy subject back in 1974; all the big players had phased array radars, but the technology was classified.

(That led to a suppressed invention - Airadar. In 1973, Rufus Applegarth, who'd had a long career developing avionics, developed a low-cost phased-array radar with a conformal antenna (not a dish, part of the leading edge of the wing) and electronic scanning (no moving antenna) and mounted it on a single-engine plane. It worked great, and Flying Magazine had a chance to see it work in flight.[1] The USAF was upset; it was much lighter and smaller than what they had at the time. Airadar was quietly suppressed, and it was years before radars like that appeared on the commercial market.)

[1] https://books.google.com/books?id=NWzlTqj0gQ4C&pg=PA66&lpg=P...

> The energy of a radar return decreases as the fourth power of the range

I'd guess that's because the power / unit-area falls off like 1/r^2 for a ball of radius r in R^3, and that's for a one way trip, so another 1/r^2 multiple for the return trip. Is that sorta-right?

Thanks exactly it.

> There's not much on electronics - nothing about how such big pulses are generated, or the clever trick which allows transmitters and receivers to share an antenna without blowing out the receiver.

Well, you have my curiosity now. Any good sources on these?

Skolnik:

http://www.amazon.com/Radar-Handbook-Edition-Merrill-Skolnik...

Ha ha, didn't realize my adviser in grad school wrote chapter 16.

On an unrelated note - Mir Publishers, font and size of the book made me reminisce about a book that I had on physics problems by Irodov. Quite a fun book it was :)

[1] https://archive.org/details/IrodovProblemsInGeneralPhysics

It is hilarious in parts, comparing choosing a radar to choosing a girlfriend. I picked up a copy from a street stall in Syria 10 years ago.

This looks very interesting, but I'd like to know from people that have already read it how relevant it still is since it was published.

I just skimmed through the whole thing, and was pretty impressed. It definitely accomplishes its goal of giving non-experts a broad view of the whole field. The author alludes to technologies from bistatic radar to compressed sensing to stealth technology that are still actively-researched topics.

As far as the basic concepts go, there's really not much new under the sun in the radar business, but there's been a lot of refinement of principles that were already known by the 1970s when the book was published. Every few pages you run into a concept that practically screams for modern DSP techniques. Matched filters, tapped delay lines, correlators, target classification algorithms, stuff like that. About the only thing that's conspicuously absent is any mention of impulse radar.

Note that both the Kindle version and full-text version have many formatting issues, but the PDF version appears to be scans of the original book.

Thanks for the very useful tip!

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