Network Assisted Global Positioning System (GPS) Direct Y Acquisition

Period of Performance: 11/17/2003 - 10/31/2005


Phase 2 SBIR

Recipient Firm

Navsys Corp.
14960 Woodcarver Road Array
Colorado Springs, CO 80921
Principal Investigator


Our proposed approach is to use network assistance to improve the robustness of the GPS P(Y) acquisition and tracking functions. This capability will greatly bolster GPS reception in low signal and degraded signal environments (e.g., tunnels, buildings, under tree canopy, and within proximity to RF transmissions). The proposed architecture is based on a Software GPS Receiver (SGR) approach, which can ultimately be embedded within a Software Defined Radio (SDR), such as the Joint Tactical Radio System (JTRS). This will provide a combined communication and navigation capability that will leverage the data link capabilities of the SDR to provide network assistance to enhance the acquisition, tracking and navigation capability of the SGR through advanced signal processing techniques leveraging the military GPS signal structure (FCTRACK). Under this Phase II effort we plan to develop and deliver a Network Assisted Geolocation test-bed based on a Software GPS Receiver architecture to be used to testing and evaluating the NETASSIST performance improvements in a MOUT environment. Since only the DoD has access to the P(Y) code signals, the commercialization strategy for this product is for military programs only. Several transition opportunities have been identified including the Joint Tactical Radio System and the One Tactical Engagement Simulation System (One TESS). The network assisted Software GPS Receiver is an ideal candidate to transition into the JTRS as a software application to enhance the GPS acquisition and tracking performance and also provide a small, lightweight, low power, low cost positioning device suitable for use in future training systems such as OneTESS.