GPS World

Tag: GPS user equipment

  • James Litton, GPS and precision ag pioneer, dies

    James Litton, GPS and precision ag pioneer, dies

    James Litton
    James Litton

    James D. Litton, GPS pioneer and founder of NavCom Technology Inc., died over the weekend at his home in California with his family at his side. He was 89 years old.

    Litton was an early contributor to the development of GPS user equipment. He also played a pivotal role in the GPS-driven transformation of global agriculture that has greatly benefited humanity.

    Litton was the director of engineering at Magnavox Research Labs when researchers were working on using CDMA for range measurements, a precursor to the GPS system. He also worked on the original proposal for GPS Phase I.

    Later, as general manager of Magnavox’s Marine and Survey Systems Division, he helped develop new and advanced commercial navigation and survey receivers for both the Navy’s TRANSIT system and the Air Force’s GPS.

    His team developed the first microprocessor-based commercial satellite navigation receivers and the first commercial GPS survey software. This led to Magnavox eventually having more than a 90 percent share of the survey receiver market.
    The firm eventually held more than two dozen patents for improvements in GPS technology.

    In 1992, Litton left Magnavox to start a consulting business. Two years later, with Ron Hatch, K.T. Woo and Jalal Alisobhani, he founded NavCom Technology Inc. With Litton as CEO, NavCom became a significant player in the GPS marketplace. Among its achievements was development — under contract — of a single-frequency WAAS-capable GPS aircraft navigation receiver.

    NavCom also began a relationship with Deere & Company, supporting more efficient and productive agriculture. This relationship was so successful that Deere purchased NavCom in 1999. Litton continued to lead the company and serve as part of Deere’s senior management team for eight more years.

    In recognition of his many achievements to the field, Jim Litton was presented the Institute of Navigation’s Hays Award in 2006.

    Among his many contributions, his impact on global agriculture might well have been his greatest, according to Brad Parkinson, the original chief architect for GPS.

    “His work transformed agriculture into a data-driven, technological industry that was incredibly more efficient,” Parkinson said. “The cost savings and increases in productivity have impacted billions around the world.”

    Jim’s family has created a memorial fund at Doctors Without Borders for those wishing to make a donation in honor of his life and many good works. Click here.

  • Sharing new thoughts on three GPS segments

    Sharing new thoughts on three GPS segments

    Possibly during the course of last month’s editorial here, “‘Nearly Perfect’ Not Nearly,” in which I called out the U.S. Air Force for lauding itself a bit much, I veered across the line separating vehemence from over-vehemence. Just possibly. Over-vehemence is a professional hazard of journalism. A gentle reader wrote in to suggest as much. He began, in his polite way, with “As always, I enjoyed your article and it made me think.” Then he offered a few of his thoughts for me in turn to consider.

    First, he urged me to weigh all three GPS segments. The space and control segments operate almost flawlessly, he averred. Except, I can’t refrain from riposting, for the times that they don’t.

    The user segment, we can all agree, is a different story. Most current GPS user equipment can be jammed and spoofed, sometimes very easily, and some have difficulty handling leap seconds and GPS week rollovers.

    The U.S. Air Force and the GPS program office cannot fix the problem with user equipment. This is up to those who manufacture, purchase, install and maintain the user equipment.

    Fair enough.

    Let’s not even get into mapping and guidance algorithms and obsolete data that generate multitudinous stories in mass media about drivers led astray and into danger “by GPS.” Those are the fault, not of the user equipment per se, but of software conjoined to a receiver in a navigation device or smartphone.

    My column in June’s GNSS Design & Test enewsletter covered the same ground and then tackled the potential costs of GPS disruption, citing a study done by Innovate U.K., the U.K. Space Agency and the Royal Institute of Navigation. This included a pie chart of potential economic losses in the U.K. that would stem from a prolonged GNSS disruption. I really should have correleated these with, or at least mentioned in the same breath, the reports done for the National Space Based-PNT Advisory Board by Irv Leveson, because there were several mismatches. In particular, the PNT Advisory Board study concluded that more than 50 percent of the value of GPS to the U.S. economy lies in high-precision uses — substantially higher than estimated in the U.K.

    Regardless of statistics, we should think, my correspondent reminded me, about the performance needs of different uses. It’s not just whether you have PNT or you don’t. The degree to which you have it is the key: accuracy, coverage, 3D versus 2D positioning and other factors determine if a technology can perform to meet a given need. Aviation requires 3D positioning for some operations. Surveying and machine control require submeter accuracy. Road use requires meter accuracy now, and submeter in the future for autonomous driving. Almost 50 percent of the U.K. pie chart, and more than 50 percent of GPS value to the U.S., requires meter or better accuracy. Except for other satnav systems, what known technology can provide this kind of performance over an area the size of a nation, whether U.K. or U.S.?

  • L-3 completes GPS military code security certification

    L-3 Communications has announced that its next-generation military code (M-code) GPS user equipment has successfully completed the final step in a government security certification process.

    L-3’s M-code GPS features advanced user equipment technology, increasing soldiers’ ability to resist enemy jamming and spoofing and performing significantly better in contested environments. The development and certification of this technology was performed under the Air Force Military GPS User Equipment (MGUE) program led by the GPS Directorate within the Space and Missile Systems Center (SMC) at Los Angeles Air Force Base.

    The certification review was performed by an independent government review team, with a focus on the security design of the L-3 GPS user equipment. The goal of these new security standards is to further protect the integrity of the navigation and timing solutions and provide required safeguards for critical information inside GPS user equipment. Work on this project will be done by L-3 Interstate Electronics Corporation (L-3 IEC), which is part of the Precision Engagement & Training sector within L-3’s Electronic Systems business segment.

    “We are pleased to be the first DoD contractor to complete security certification for our new M-code GPS user equipment,” said Michael T. Strianese, L-3’s chairman and chief executive officer. “L-3 is ahead of the technology curve, and we are delivering critical innovations that have significant applications inside DoD markets and on several U.S. Army initiatives. Timely delivery of these advancements to the warfighter is essential as they respond to current and emerging threats on the battlefield.”

    Based in Anaheim, California, L-3 IEC is provider of positioning, navigation and timing products and solutions and long-term supplier of critical navigation, test instrumentation and missile tracking systems for the U.S. Navy’s Fleet Ballistic Missile (FBM) weapon systems, including the Trident submarine.