Cooperative Networked GPS signal acquisition

ABSTRACT: The biggest demand on a military receiver has been from the time required to search and acquire for the military signals when an accurate internal time reference is not available. Prior research by NAVSYS into network assisted GPS approaches used the JTRS network itself to transfer time from another GPS receiver to reduce the initial time uncertainty and speed the acquisition time. This required at least one receiver on the network to have already acquired and tracked the GPS signals. Under this SBIR, we proposed to develop methods to reduce the direct P(Y) acquisition time under situations where no unit on the network has yet acquired a GPS solution. The cooperative signal acquisition algorithms shall use shared data between network participants to speed direct P(Y) and direct M-code acquisition to reduce the search space for disadvantaged units, and allow longer correlation times for weak signal and high interference environments. We shall develop a Phase II plan for a prototype system to be used to demonstrate the performance under live tracking conditions of the cooperative acquisition approach and document the Phase I simulation results, and proposed Phase II, system architecture and demonstration plan in the Phase I report. BENEFIT: The NAVSYS VMAG (Vector Mapped Assisted GPS) and NAMPA (Networked Assisted M-Code Puncture Acquisition) technologies will provide rapid TTFF (Time to First Fix) initialization among a networked user groups. Military applications will be pursued in all major DoD branches by tailoring the implementation of this technology to their specific needs. Civilian applications include public sector infrastructure and logistics, which will compliment private sector applications such as commercial logistics and mobile device applications.