There's no radar interface to openCPN, largely because all radar units are proprietary. Even if a manufacturer allows PC connectivity, the interface is closed and typically licensed only for a large amount of money
. The Koden (Si-Tex) radars are supported by a number of packages such as Coastal Explorer and Expedition, but only as a fairly expensive add-on. Nick has been on-and-off with support for the Navico broadband
radars in Expedition, but I believe Navico
charges at least $1,000 per copy for a license
. Currently I believe it would be impossible to support an open source interface to any radar unit given the licensing issues. In short, don't look for it any time soon unless a radar manufacturer decides to open up their interface for free.