NavList:

Dear John,

I think Frank is talking about the vertex of the GC, it maximum and minimum, like the in a GC sailing:

·         Vertex B->max: dB/dL = 0

·         Node (B = 0), cross with the equator

where B is the latitude and L the longitude

regards,

---

Andrés Ruiz

Navigational Algorithms

https://sites.google.com/site/navigationalalgorithms/

PS: Recently I have a copy of your book “Celestial Navigation in the GPS Age”, a good reading!!!

Frank,

To understand the Lord Ellenborough trick, It seems that I need to know what the Pole of a great circle is. I've never come across this term,

Also, what do the two asterisks mean (as in *pole*)?

JK