The technique was first used in the early 1960s, when the technology used in and made them small enough to attach to , and is now widely deployed for a variety of wildlife studies.
Best of all, it was so much more reasonably.
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And this is like one of those wonderful dreams that you yearn to go right back into when awakened.
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For aerial use, where the horizon may extend to hundreds of kilometres, higher frequencies can be used, allowing the use of much smaller antennas.