The U.S. Navy recently completed installation of it's new Digital Radar Video Data Distribution System (DRVDDS) aboard the USS Saipan and USS Nassau. These are the first of four LHA-class amphibious assault ships to be retrofitted under the Navy's LHA Advanced Combat Direction System (ACDS) upgrade.

The DRVDDS is a ship-board Local Area Network (LAN) distribution system for radar video and IFF messages. Data from all radar and IFF sources on the ship is available at all times on the LAN, and can be selected independently at any OJ-724(V)/SYQ-24(V) tactical display console. The DRVDDS includes commercial off-the-shelf (COTS) radar signal processing and scan converter products developed by Folsom Research.

Folsom Research Model 9415RB Radar Broadcaster Boards (RBBs) interface the ship's radars to three Fiber Distributed Data Interface (FDDI) LANs. The RBB is part of the Radar Broadcast Equipment (RBE) which includes a CPU controller, one or more RBBs and one or more LAN interface boards.

The RBB is a VME board which receives Analog Radar Video (up to 4 channels), Trigger, and Azimuth signals from the radar and processes these inputs to provide data to the LAN. Azimuth and Range Decimation techniques are used to compress the radar video. Azimuth decimation is done via peak detection or averaging. A user-selectable number of output wedges (512, 1024, 2048 or 4096) is generated for each revolution of the radar antenna. Range decimation compresses input samples to 2048 or 4080 range bin data samples per output wedge. This data, along with the header information, is output to the LAN interface card via VME-64 block transfers. Each of the four radar videos can be transmitted as an independent data packet on the LAN.

Folsom Research worked closely with SPAWAR Systems Center, San Diego (SSC San Diego) and the Navy's DRVDDS Project Engineer Doug Lasniewski to develop the Radar Broadcaster Board to meet the DRVDDS requirements