NavList:

nsg21 wrote:

"I think the note regarding iterativity applies not just to a formula but to entire concept of Hilaire LOP. If AP is widely different from actual position, calculated azimuth may be noticeably different from "true" azimuth (the one that would have been observed if it was possible). As a result, LOP would be slightly off from "true" LOP. On a good side, the new position obtained this way is usually close enough to true position, so if it is used an new AP (and all azimuths and distances are recalculated for this new position), your are golden."

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I can never pass up the above misconception.
We've discussed this before, but the intercept method is not iterative. The calculation from ANY AP produces a true azimuth to the body, and the intercept marks an exact point on the LOP (a PLOP). (And in all practical cases, plotting the intercept as a rhumb line on a Mercator chart has negligible error.) Drawing a straight line through the PLOP is an approximation, but not an an iteration. If it's desired to repeat the AP selection and associated intercept and azimuth calculations for another PLOP, we're simple tracing out the LOP -- exactly. No approximations, no iterations. Tracing the LOP point by point is not an iteration. Each PLOP is exact. See the attached figure.

Happy PLOPing,

JK
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