A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Byron Franklin
Date: 2012 Sep 5, 12:34 -0700
Byron: Iwant to add more information and idea to piloting and ploting.
The franklin technique works when using the magnetic compass. the big difference is magnetic compass,s have more radon error them a gyro.
The system error can be easly found and corrected making even the mag
compass give better fixes. If you are in an place with low variation you need not correct, the techique will find and correct for you. 2 things to note:
(1) trangle center will give bad set and drift information, note the 2 close will give good set and drift. (2) In-order to get 100% error pick the far possible NAVAID, Although the closer will give 80% or better.
VISUAL NAVIGATION and the LINE of POSITION. LACK OF PROPER EMPHASIS ON LOPS ACCURACY.
The COMNAVSURFORINST 3530.4B 28 Jan 08 States and start with “While special significance must always be placed on piloting,” and continues, “Studies have shown that navigation accuracy can be adversely affected by a number of factors, including:”
b.” Lack of proper emphasis on navigation accuracy.”
C. “Improper determination of set and drift to Dead Reckoned positions.”
It continues “about proper training. The instruction lays a good foundation but the Navy Schools and Publications teach a hindrance to both b.&c. In my apprentice as a Quartermaster striker and training, I took a bearing of a conspicuous water tank, far up the bay, trying to get a fix. My chief said “that tank never cuts in; she is plotted on the chart incorrectly.” Later in the week we were operating up the bay near to the water tank, we used it to get reasonable fixes with small triangles’ on the chart. The idea of the far tank verses the same tank when closer greatly impressed me, especially, because all publications and teaching, teach all Lines of Positions are equal, and Places the fix in the center if there is a triangle (cocked hat.) With time and experience I work my way up to the senior QM2 and chart plotter. I was able to get that good fix, finding set and drift and gave recommendation to the CONN. A new Commanding Officer came aboard, I was replaced with navigation schooled Officer, but after many replacements the new CO. reassigned me to chart plotter. The ship was a World War II Liberty hull with the original gyro and large compass errors. What made the difference, between the schooled Officers and the QM2 was my experience; I cheated on what was taught and in the books.
I learned that treating the LOP as equal was wrong and a hinder to accurate fixes, equally to set and drift.
I understood that the radian rule (rule of sixty) controlled each line, and a close NAVAID gave a close Line of Position to the observer while Far NAVAID gave a farther closest line of approach. How did I get that best fix possible for any given NAVAID arrangement?
I would simply select two of the closer NAVAIDS with a good sped for my fix. The third would not be part of the fix, but an indicator of accuracy. The two closes LOP. Intersection would be the best fix possible. The third told me how accurate and gave me compass error and correction.
The base to NAVAID selection, don’t do the math, but to look at the CHARTED NAVAIDS knowing that one NAVAID three times the charted distance of another closer NAVAID will have a closest point of approach CPA. Three time the distance of the closer. There are other factors of geometry that can slightly benefit the fix accuracy, but you can quickly select the best fix possible, using this simply idea will greatly improve fixes and finding a true “SET and DRIFT.” Today’s, present teaching, and is Damage to accurate fixes as being taught in schools and in the publications by the Navy. This teaching is based on lack of knowledge and can be easily disproved by simple chart work This technique has been evaluated and taught to many Officers on YP’S at OCS and Annapolis MD.
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