2026 Fellow

Presented to: Dr. Philip A. Dafesh

Citation: For seminal and sustained innovations to the design of modern satellite navigation signals, receiver implementations, and antijam technologies, enabling resilient GNSS and cislunar PNT capabilities

Dr. Philip A. Dafesh is a pioneering architect of modern and next-generation satellite navigation, whose three decades of innovation have reshaped global PNT signal design, resilient receiver technology, and adaptive space-based navigation. His contributions span every layer of GNSS advancement– from waveform theory to antijam signal processing to the foundation of cislunar PNT to GNSS software-defined radio implantations.

Dr. Dafesh originated multiple constant-envelope signalcombining techniques—Coherent Adaptive Subcarrier Modulation, Quadrature Product Subcarrier Modulation, and the Phase-Optimized Constant-Envelope Transmission (POCET) family—enabling unprecedented transmitter efficiency for multi-signal GNSS. These methods directly influenced GPS Block III and inspired the Galileo E1OS CBOC structure, establishing blueprints for multi-component navigation waveforms.

During GPS modernization, he championed the M-code pilot component, delivering a 3 dB antijam improvement over legacy Y-code at equal power—the most significant antijam performance gain realized during the transition to modernized military GPS signals. He led the implementation of interleaving and LDPC coding for the L1C signal design, improving GNSS data thresholds by 2.5 dB. He further proposed L2C’s low-rate channel, improving coldstart and weaksignal acquisition of GPS signals by at least 3 dB. His antijam and interference-resilient research—including Cognitive Antijam Receivers and BLISS technology— fundamentally advanced adaptive suppression of matched spectral interference, directly shaping future military receiver architectures.

Dr. Dafesh’s innovation in NTS3 flexible waveform development led to five high-priority signal experiments central to the U.S. vision for on-orbit reconfigurable PNT. His LunaNet AFS signal work established the first interoperable cislunar navigation standard adopted by NASA, ESA, and JAXA. He also spearheaded the Lightweight Satnav encrypted military signal, advancing lowSWaPC resilient PNT for emerging platforms.

Dr. Dafesh has published 70 papers and holds 21 issued patents. He holds an MS and PhD degree in Electrical Engineering from UCLA.