NavList:

I am sitting here on the ship in the port of Galveston, TX. I was pondering the Franklin plotting technique as it pertains to compass error while thinking of how I was going to teach it to my cadet.

It occurred to me that while the classic method is excellent and well thought out when there is positional ambiguity, I think that it can be simplified. In these days of highly accurate satellite navigation where you know where you are, and you know where that distant navaid is, I think that we can shorten up the procedure a bit.

Instead of using two visual bearings on nearby objects to determine a fix (with the error within it, albeit minor), can't we take a carefully plotted GNSS position instead? We then take the bearing on the distant object for the indicator and can rapidly determine gyro error based on a comparison of the bearing and the direction of the line between the Navaid and your GNSS position.

This technique can also be done underway if you have someone record the GNSS position at the same time as the indicator bearing is being taken. This would eliminate the error of the change in position due to forward motion in the time it takes to shoot the 3 bearings.

Am I off course in this thinking?

Jeremy
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