DoT Disses DoD’s GPS Chops

January 9, 2014  - By
Image: GPS World

The departing Deputy Secretary of Transportation, John Porcari, wrote a letter in the closing days of 2013 opposing the U.S. Air Force’s announced plans to begin broadcasting Civil Navigation (CNAV) message-populated L2C and L5 signals as early as April 2014. Military personnel are incensed over what they see as Porcari’s impugning, when not ignoring, the Air Force 35-year track record of broadcasting the gold standard of global navigation satellite signals — something in which Transportation has zero experience.

Porcari alludes in his December 27 letter to “non-standard engineering tools” and “non-standard operations” that he believes would come into play for early CNAV broadcast. “These have the potential to inject human error, which may result in unacceptable GPS constellation operation.”

What Porcari means by “non-standard” he does not specify, although he confesses to unease as “the ability to monitor these signals, [without which] the system will not know if the L2C and LS signals are within specification. Given these risks, DOT is concerned that the CNAV messages could provide hazardously misleading information, impacting GPS safety-of-life, protection of property, and economic security applications.” The full text of the Porcari letter is available here.

In addition to questioning Air Force 2 SOPS ability to broadcast an accurate, compliant signal containing CNAV, the letter appears to ignore — or be ignorant of — the 17 official U.S. government/military monitoring sites for GPS distributed around the world, not to mention thousands of other monitoring sites run by government agencies such as the Jet Propulsion Laboratory, the National Aeronautics and Space Administration, and the National Geospatial-Intelligence Agency, and by many universities such as Stanford, Ohio State, Cal Tech, Massachusetts Institute of Technology, and many other international institutions around the world. Many of these sites collaborate under the rubric of the International GNSS Service.

Finally, two private corporations monitor and correct all GPS signals both from space and on the ground: John Deere and Trimble Navigation. Both companies run commercial, automated GPS signal monitoring systems that that report any glitch, change, power fluctuation, or anomaly in the navigation message for all GPS signals with an average two-second notification time.

“This letter is so much BS,” fumed one source who wished to remain anonymous, “coming from an agency that is in arrears in its GPS payments to the tune of more than $70 million and has no clue how to represent the global GPS user. GPS is a ubiquitous system, not just a tool for the DOT and the Federal Aviation Administration. GPS needs to implement these signals for all users and as a modernization program that was promised to be in place years ago.”

Porcari is leaving for the private sector.


6 Comments on "DoT Disses DoD’s GPS Chops"

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  1. Terrance Mish says:

    These GPS people are always getting the knickers in a twist over one thing or another. Last year or so it was a company called Lightsquared, now it’s something else.

  2. Bill S says:

    Can someone at DoT spell L5 correctly?

    Looks like a complementary letter before the shiv.
    Government is no different than private industry.

    There is much behind the scenes in this matter.

  3. Leatherstocking says:

    If USAF ran the GPS program like DoT runs their component agencies, we’d all be using GLONASS. Porcari is non-technical and I can’t find any “achievements” from his time at DoT or Maryland DOT. Technology is critical in transportatio and the professional public administrators are not up to the task. Whether it’s FAA, MARAD, FRA or any of the other constituent parts of DoT, they are decades behind the curve in selecting and implementing technology.

  4. Kevin R says:

    Will be glade to see Mr. Porcari pushing papers somewhere where he’ll no longer screw up GPS.

  5. Iron City says:

    So why would the DOT/FAA have a problem with a navigation message being transmitted before OCX is ready to control it? Maybe they are sensitive to signals being out there that somebody will use for navigation that aren’t approved by FAA for navigation? Should be able to use a signal that some really smart people at a university or research lab say is good. What could go wrong? Who would be liable?

  6. Rick Bennett says:

    Maybe the DOT is just pointing out that DOD has overclassified its information and taken a “trust us, we’re the pros” attitude. This might seem justified to people accepting risk for troops at war but it holds short shrift to those responsible for mishap prevention and disaster response. Ultimately, lack of transparency impedes sharp minds from advancing and from degrading the navigation programs; DOD thinks they need to do the latter while other folks see so much advantage in the former.