That is what they said they were for, yes. Super neat, huh? Or maybe they were a precursor to HAARP, who knows? Very cool though.

There are also super long line buried antenna arrays that were/are used for ELF and SLF signals to communicate with submarines that are wicked cool.

If you ever get bored you should build a crystal radio set and run a long line antenna, it's a cool project. A radio receiver that requires no battery, it literally works on the RF power it receives.