Letters to the Editor

October 1, 2013 0 Comments

Orbital Planes, Nightmares, Pioneers

Good morning, Dr. Langley,

I have a seven-year-old drawing of GPS satellites in their orbital planes that I found (can’t recall where) some years ago, either on a website or from a colleague who attended some GPS forum. Would you know of a site where I can find current information on GPS satellite locations, which ones have been decommissioned, and which ones have been replaced?

— Grace Pazos

Richard Langley replies:

I don’t know of a plot that shows the locations of all decommissioned and/or replaced satellites (some of them would have been boosted out of the GPS orbit planes), but relatively current information on the active and backup satellites can be found here, and a plot here (and depicted below). I update the table and plot roughly every six months. Earlier versions are available on request.

Constellation snapshot for a specific date/time: GPS week 1749 (725) and GPS seconds 86400 = July 15, 2013, at midnight GPS Time.

Constellation snapshot for a specific date/time: GPS week 1749 (725) and GPS seconds 86400 = July 15, 2013, at midnight GPS Time.

Survey Scene Newsletter Mail

Thanks for the insightful update on the ESRI User Conference and the Survey Summit. For those of us who can’t afford to travel, it helps to get the scoop on these events. It is interesting to me that the push towards the future includes heavy emphasis on lighter and simpler small platform apps, cloud-based GIS, and 3D visualizations, and less emphasis on the building blocks of geodesy, cadastral data, and surveying. It almost seems like the GIS community is pushing the hard stuff under the rug and focusing on what is new and shiny. And doing this while talking about higher quality standards.

Keep up the good work, thank you.

— David Scherf, Manager of GIS/Technical Services, Torrington, Connecticut

Eric Gakstatter replies:

Thanks for the comments. If you’ve followed my series “Nightmare on GIS Street,” you’ll see that I’m trying to raise awareness of the importance of geodesy in GIS. I don’t believe that most people are sweeping this subject under the rug because it’s a difficult subject, but just that they aren’t aware that it’s a problem. Secondly, if they do recognize the problem, many don’t know how to solve it. There’s definitely a knowledge gap, and an opportunity for geodesists (or qualified surveyors) to contribute.

Defense PNT Newsletter Mail

Thank you for your tribute to Col. Duke Kane’s many contributions beyond the GPS community. I was also sad to hear of his passing. I met Duke in the late 1980s and watched with considerable interest as he established the GPS International Association.

He felt strongly that the GPS users needed their own forum to voice user interests similar to that which had recently been established for GPS industry via the U.S. GPS Industry Council. His foresight and energy will be missed.

— Jules McNeff, Overlook Systems Technologies, Inc., Vienna, Virginia

Don Jewell replies:

Thanks for your kind words. Of course you and I knew Duke well, and you are correct, he made many significant contributions beyond GPS, even though it was a major accomplishment in which he was always very proud to have had a role to play.

Duke Kane was my uncle, and I can tell you the germinal event that grabbed his interest in flight. While a young boy, Duke and my father Jack (Duke’s older brother) pooled their resources and bought a very popular adolescent novel by Nordoff and Hall (these authors also wrote Mutiny on the Bounty) called Falcons of France, written about two young American boys who volunteered to fly for France in World War I before the United States entered the conflict. Duke’s eyes were set skyward ever after.

— Michael Kane

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