Posted By Bob Skaggs on 10/1/2008 at 1:49 PM

This was in POB's eNews, so I guess it is Ok to cut and paste it here;

On Sept. 23, the U.S. Department of Defense (DoD) published notice that it will discontinue support of codeless/semi-codeless access to GPS on Dec. 31, 2020. "This is the first action, in the history of GPS, which will render a massive amount of GPS equipment obsolete," said Eric Gakstatter in GPS World magazine on June 5, 2008.

What does that mean to land surveyors? According to Gakstatter, a GPS consultant, it's land surveyors and those in the engineering, construction, deformation-monitoring and high-precision GIS industries that are going to be affected the most.

"In real terms, this means that any dual frequency receiver not designed to use L2C will essentially become a paperweight after December 31, 2020," he said, noting that this includes most dual-frequency receivers designed from the 1980s to the early 2000s.

The end date, which was based on projected budgets and current launch schedules, is dependent upon the availability of at least 24 GPS satellites broadcasting the second and third coded civil GPS signals. The DoD will reassess the transition date if significant GPS program delays arise, the Federal Register notice states.

The DoD wants-and expects-users to transition to new equipment over the next 12 years. If you don't, there is no guarantee that GPS equipment using codeless/semi-codeless techniques will work. "After the planned transition date, the characteristics of the L1 P(Y) and L2 P(Y) signals transmitted by any or all GPS satellites broadcasting two or more civil-coded signals may change without further notice and may preclude the use of P(Y) coded signals for high accuracy applications," the notice states.

Regardless of whether it makes sense from a technology standpoint, this transition is going to hurt financially. According to Gakstatter, thousands of small- to medium-sized business owners depend on codeless/semi-codeless dual frequency GPS technology. "It's hard to swallow that my $40,000 system has a date with the trash bin," Gakstatter said.

I encourage you to read Gakstatter's full article, "Is Dual-Frequency GPS - As We Know It - Becoming Obsolete?" Then, in POB's November quick poll, we'll ask you to cast your vote on how-or even if-this transition is going to impact you.

-Wendy Lyons, eNews Editor

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