In a masters thesis I was proofing for a client (on the topic of radio astronomy) he titled one of his sections "Multiple Antennae Arrays."
Now that seems redundant to me, since either "Multiple Antenna Arrays" or "Antennae Arrays" pretty much accurately describes the technology of multiple linked radio telescopes. "Antennae" is already plural.
I should note that he was doing this at Cape Town U, and over the years he's been there he's picked up the British English style and used it in his thesis. I'm aware of some of the differences between BE and AE, but I'm not an expert. Still sounds redundant to me.
I Googled "multiple antennae" and got 34,400 hits, whereas "multiple antenna" yields 383,000. So I suspect that usage is indeed redundant. Any feedback from BE experts most appreciated. Thanks.
The syntax makes it ambiguous:  many antennae  or  many arrays ?
(It would be clearer, and perhaps sound better,  with prefix:  multi-antennae.)
Regarding redundancy, if  you use the word multiple merely as indicator of plurality, then is it not always redundant in any languages that feature  pluralized nouns?  Then the only time that it is not redundant is when used as emphasis of plurality.  (That also means that whenever it appears in English, there should be that intention behind it;  so , in other words again, it is never redundant.)
There could be a technical intention here:  an array usually denotes a 1-dimensional string or series.  So a combination of multiple arrays gives a multi-dimensional matrix.  However that term could be subject to varied interpretations .
RobertB asked: The syntax makes it ambiguous:  many antennae  or  many arrays ?
I had to go back and re-read that section to be sure, but no, he's talking about only a single multiple-antenna array. Hadn't seen that ambiguity until you pointed it out. So I like your suggestion of using that hyphen. I'm definitely gonna suggest he change that section title, thanks.
On the redundancy aspect, I'm glad you agree. That was my first impression and the reason for my post. If a noun is pluralized, it shouldn't make any difference regardless of the language. But I've been surprised by British English many times which is why I asked.
Most recently I ran into this usage:Â I thank my father, who stayed up late helping me with my maths.
Using that plural form of "math" at first looked like a typo to me. But after looking around I discovered that was a British English convention. That, by the way, was from the dedication on this same masters thesis.
Heimhenge said
In a masters thesis I was proofing for a client (on the topic of radio astronomy) he titled one of his sections "Multiple Antennae Arrays."
Would you like to party on a sixty feet yacht? Would you built a six feet fence?
I used to drive past what I presumed was Ohio State's radio telescope (There was no sign). It was antennae in a single 2 x 2 array. If Dennison were to have an Astronomy department, and they were to build a similar radio telescope, and then Muirfield golf course built one, it could be said that central Ohio had three antenna arrays, but I cannot imagine how you could have multiple antennae arrays.
Not impossible. Just exceeding my imagination. Feel free to explain how one would create an array where each element is not elemental.
There are 3 Â conventions by which a noun is used as attribute: unchanged, pluralized, and as participle:
A 66-foot yacht.
A 100-guests reception.
A multi-pronged strategy.
So  A  multi-antennae array  is not so out of the ordinary.