Inside GNSS Media & Research

NOV-DEC 2018

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18 InsideGNSS N O V E M B E R / D E C E M B E R 2 0 1 8 ing on GNSS 25-plus years later! What has kept me involved is that one can never get bored working in this field. GNSS involves so many sub-disciplines – electrical engineering, mathematics, statistics, geodesy, geophysics, space weather, relativity, etc., etc. I am still learning something new every day." In those 25+ years, Hegarty has been involved in several key projects. Here are just a few: • GIC/WAAS – "I've supported the FAA's WAAS program on and off for decades," Hegarty said. "is system is of course now operational and since 2003 has been used for navigation of aircra in IMC. I con- tributed to the message formats and receiver algorithms." • GPS Civil Signals – Hegarty helped select the GPS L5 frequency and then co-led, with Dr. A.J. Van Dier- endonck, the development of the initial GPS L5 signal specification (RTCA DO-261) that was later con- verted by the U.S. Air Force (USAF) into what is now the Interface Spec- ification IS-GPS-705. "e initial signal specification defined most of the L5 signal characteristics, includ- ing the modulation characteristics and the flexible message format later adopted for use also by L2C," he said. "I also participated in the GPS L1C design team and contrib- uted to the development of the L1C modulation design and message format." • DOT GPS Adjacent Band Compat- ibility (ABC) study – Hegarty led a MITRE team that provided the GNSS signal generation equipment for the Department of Transporta- tion (DOT) ABC testing at White Sands Missile Range. "We operated the equipment and also nearly a dozen GNSS receivers for that test. We also were significant contribu- tors to the analysis and co-authored the final report. We worked very closely with DOT leadership and other contributors, such as Zeta Associates, USAF, NASA, and vari- ous GNSS receiver vendors." What He's Currently Doing And the beat goes on. Hegarty's most recent promotion came in 2018 when he was made a Technical Fellow, and he continues to break new ground: • Dual-frequency Multi-constella- tion (DFMC) GNSS avionics – "I co-chair, with Dr. George Ligler, RTCA Special Committee 159 (GNSS) which develops GNSS avi- onics standards and other GNSS products." SC-159 participants come from around the world and represent most major avionics ven- dors, airframers, and civil aviation authorities. Until May 29, SC-159 served as a Federal Advisory Com- mittee for DOT/FAA. "Since then," Hegarty said, "we have continued to develop standards as an inde- pendent standards organization functioning in much the same way despite the change [For more on this topic go to: http://insidegnss. com/rtca-is-no-longer-an-faa- advisory-committee/]. SC-159's cur- rent focus is on the next-generation GNSS avionics, which will be dual-frequency (L1/L5) and multi- constellation – GPS+Galileo+ pos- sibly BeiDou/GLONASS – whereas most current-generation avionics only process GPS+SBAS C/A-code signals." A DFMC GNSS antenna standard was approved in June. e DFMC GNSS (SBAS) receiver standard is scheduled to be com- pleted in two iterations – an initial version for verification/validation in 2020 and a final version in 2022. Each of two iterations (initial/final) of DFMC GNSS (GBAS) standards are scheduled to be delivered a year aer the corresponding GNSS (SBAS) standard. • GNSS Radiofrequency Compat- ibility bilats/multilats – Since the late 1990s, Hegarty has been a Chris Hegarty enjoying a bike ride and vacationing at the family home in Maine. HUMAN ENGINEERING

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