Submarine Navigation in a GPS-Denied Environment Navy SBIR FY2015.1 Sol No.: Navy SBIR FY2015.1 Topic No.: N151-032 Topic Title: Submarine Navigation in a GPS-Denied Environment Proposal No.: N151-032-0924 Firm: NAL Research Corporation 9385 Discovery Boulevard Suite 300 Manassas, Virginia 20109-4405 Contact: Ngoc Hoang Phone: (703) 392-1136 Web Site: www.nalresearch.com Abstract: The Iridium satellite constellation consists of 66 low-Earth orbit (LEO) satellites, primarily used for global data and voice communications. The satellites transmit in the L-Band at carrier frequencies from 1616MHz to 1626.5MHz. Using one of the Iridium satellite's paging channels to broadcast time and frequency measurements, a ground receiver can collect these measurements for computing position fixes. Unlike GPS satellites, Iridium satellites use spot beams to focus their transmissions on a relatively small geographic area. Each satellite supports 48 spot beams. The Iridium satellite spot beams provide a unique mechanism that is extremely difficult to spoof or jam. NAL Research proposes to develop an Iridium position navigation and time (PNT) receiver to collect Iridium signals for geolocation determination. The receiver will have similar form-factor as a commercial GPS receiver or a SAASM GPS receiver. It will provide ocean platforms an alternate method for truly global (pole-to-pole) geo-positioning. Benefits: Banks and stock markets rely on GPS timing to record the exact transactions. Road and rail transportation networks rely on it for tracking the movement of freight. Power companies and other utilities rely on accurate time to enable efficient power transmission and distribution. GPS has become a vital source of information with significant economic benefit. More than 3.3 million U.S. jobs are estimated to rely heavily on GPS. Given the huge commercial market in GPS devices, it is of paramount importance that GPS is reliable, available and secure. There is clearly opportunity for alternate solutions to position fixing. Return