NavList:

Thank you Yves for your kind and nice comments. We are all onboard the same vessel as I can see!

RE: your own paragraph numbering:

1 - Happy to see that MPS can accomodate as many bodies as needed. This is what I thought, but I was no longer sure. Therefore, we can definitely now list MPS as a strong player in 4G.1, and the only one published performer so far in this 4G.1 category.

3 - As Gauss's method is limited to equal altitude observations, then it probably falls closer to the "genuine" "Douves's Problem so clearly defined by Frank lately (RE: introduction lines of https://navlist.net/m2.aspx/LOPs-without-DR-Position-Cou%C3%ABtte-feb-2015-g30440) 

5 - Yes please, be so kind as to send me a copy of  General Hourneau's paper. This way, I am also sure to recover my own sleeping copy too ...

What definitely rang a bell during my internet research yesterday was picking up the word "canonical" (from: "canonical equations") off the internet abstract (http://cat.inist.fr/?aModele=afficheN&cpsidt=19474690). That is M. Hourneau indeed I had been presuming during this exploration! One correction of importance though ... General and not Colonel: my most sincere apologies to you General! (if you are reading me).

7 - Yes, I totally agree: considering the Earth as a Sphere rather than an Ellipsoid introduces for the Moon a systematic error on its computed parallax reaching 10" of arc under extreme cases: Moon closest to the Earth and very low apparent altitudes observed from high latitudes (and maybe also extreme Moon Declination, but I do not remember for sure whether the Moon Declination is a relevant variable here). Whatever ... for apparent altitudes below about 10° and to a precision better than 0.1' the Moon Parallax correction does remain Observer's Latitude dependent.

*******

Again, what really puzzles me is that method 3G.1 is so straightforward, so immediate (if not "so easy") that I would be very surprised if it had definitely not been published somewhere else before 1976.

But we all know of a celebrated similar case quite amazing too. Marcq Saint Hilaire's method is also very simple, if not "so simple" and so much easier than most of - if not all - other methods in use at its time and it is so powerful too! And it nonetheless was published in 1875 only.

However it might not be a sufficient reason to claim: Let's then wait for a CelNav tremendously simple and amazing discovery by Year 2077!

Well .. I am to conclude here exactly like I concluded yesterday:

I am still interested in knowing wether somebody published (when and where ?) a solution matching the "Geometrical 3D/3 Plan Method" before it was published in France in 1976.

Thanks again to you Yves

Kermit

Antoine M. "Kermit" Couëtte