Radio Hams test APRS underground

Bob Bruninga, WB4APR, has been testing how the amateur radio Automatic Packet Reporting System (APRS) can be used to extend radio communications underground

Bob led a group of radio amateurs earlier this month to Mammoth Cave - the world’s longest known cave system - at Mammoth Cave National Park in Kentucky to test how the Automatic Packet Reporting System (APRS) can be used as a means to extend radio communications underground.

“When used underground, VHF and UHF radios can only work within a few hundred feet of each other and only when in the line of sight of another radio,” “This makes routine use of these radios of little value when underground; however, when APRS radios act as packet digipeaters, these few hundreds of feet can be extended by an order of magnitude.”
— Bob Bruninga, WB4APR

Bruninga, a senior research engineer at the US Naval Academy, developed APRS as a global, on-air protocol for supporting handheld position reporting and text messaging via VHF radio.

Read the full ARRL story - http://www.arrl.org/news/bob-bruninga-wb4apr-takes-aprs-underground