Category Archive for 'GNSS'

What a difference eight years can make! My September 2006 GPS World article “Managing the GPS Constellation for Today’s Needs,” dealt with GPS performance issues many high-precision users then faced. Demanding applications of real-time precision positioning, such as precision agriculture and machine control, did not find enough satellites in view to support their needs.  I […]

China recently issued a performance standard for the BeiDou Navigation Satellite System (BDS). It is available at I took a quick look comparing the BDS Open Service Performance Standard to the GPS Standard Positioning Service Performance Standard and here is what I came up with:   I coded the table to show green for […]

In May 2007, I authored an article in GPS World looking ten years into the future and envisioning how the GNSS field would operate at that then-distant time. Reviewing my assessments, I see that I was both accurate and wide of the mark with my predictions. The prediction that has proved accurate was that the […]

While GPS offers a ubiquitous, precise, and reliable positioning and timing service to much of the world, in many cases this service falls short. Anyone who has walked into a building with a GPS receiver actively displaying a location is aware of the immediate effect of the loss of signal. While this is an extreme […]

The U.S. has provided the highly accurate and dependable GPS service to users worldwide for nearly two decades. In addition to this service, the U.S. has made corresponding commitments as to the types and quality of current and future GPS service through various documents, such as the GPS Standard Positioning Service Performance Standard, the Federal […]

Today, the civil positioning, navigation, and timing (PNT) community needs a clear and concise statement of PNT needs. This statement should incorporate all aspects of PNT services and all applications and

On September 8, 2009, the US Coast Guard Navigation Center issued a notice reporting a pending GPS service anomaly for September 11, the anomaly being a noticeable increase in dilution of precision (DOP) over an extended period in various parts of the world.

Recently someone I know sent me an email titled “GPS in trouble?”, asking me if I had any information about what happened. He was responding to

We operate our business in Newport, Oregon, and although much of the work we do involves the Global Positioning System (GPS), I can’t help but thinking some of the methods we employ could be applied to managing our ocean resources. Let me explain.