NavList:

Second, The Royal Institute of Navigation, is serious institution, and a peer reviewed procedure is used before publication.

So, I feel that we all should be proud of it.

...and is good for NavList.

I agree with Gary, in practical CelNav, the intercept method, MSH LoP, works fine under the assumptions of real navigation. Nothing new on the horizon.

The equation of a CoP is based on geodetic coordinates (geographical, astronomical); latitude an longitude, and geocentric ones; GHA  and dec. And it is independent of the model used for our planet or others: sphere,  ellipsoid or geoid.

Celestial sights give us geodetic latitude and longitude, no geocentric ones.

See: Vector equation of the Circle of Position

The worth of the paper is that shows moving, advance or retire, a celestial line of position is a bad assumption for general case and due to a mathematically correct approach. The intercept method is a good enough approach for this in the near surrounding. 

If the whole problem is taken into account, the solution is as an engineering or astronomical problem: 

peer review is harder here :)

Best regards Robin.

Fair winds.

The only with i do not agree is the claim that: "On the sphere, points on the LoP all lie the same geodesic distance from GP; however this is not true for an ellipsoid".

I feel that comes from the geometric point of view: cutting the ellipsoid with a plane, but this is not the nature of the CoP.

Great thoughts!