To measure the length of a lunar orbit, one needs to see any prominent stars that the moon is passing by in her orbit.
This sort of procedure is implied in Indian astronomy, and other traditions, where the sky was first divided into 28 or 27 equal parts, called lunar mansions (nakshatras).
The lunar mansion on a given day was identified by the name of the lunar mansion seen behind it. In B.C. 2350, the system started with the spring equinox which stood on the seven sisters or Krittikas.
This was in the Zodiac constellation Taurus the Bull, but the mansion, one of 28, was called Ashwini – the Horse’s Head. In this way Indians still speak of “the moon in Ashwini”.
The division into 28 probably came from the observation of Saturn’s loops which resembled the twenty seven and a third days for a lunar orbit, though the first is a frequency of synods while the latter is a frequency of earth rotations, both relative to the ecliptic / Signs / Mansions.
This video introduces an article on a Scottish iron-age stone tower or brock which encoded the size of the Earth.
In the picture above  the inner profile of the thick-walled Iron-Age broch of Dun Torceill is the only elliptical example, almost every other broch having a circular inner court.
Torceill’s essential data was reported by Euan MacKie in 1977 : The inner chamber of the broch is an ellipse with axes nearly 23:25 (and not 14:15 as proposed by Mackie).
The actual ratio directly generates a metrological difference, between the major and minor axis lengths, of 63/20 feet. When multiplied by the broch’s 40-foot major axis, this π-like yard creates a length of 126 feet which, multiplied again by π as 22/7, the simplest accurate approximation to the π ratio, between a diameter and circumference of a circle, as used in the ancient and prehistoric periods., generates 396 feet. If each of these feet represented ten miles, this number is an accurate approximation to the mean radius of the Earth, were it a sphere.
If we take the size of the moon in that model, as being 3/11 of 396 feet this would give a circle radius 108 feet and one can see that, using the moon, the outer perimeter of the brock was probably elliptical too.
Thank you for watching.
You can view the full article on sacred dot number sciences dot org, searching for BROCK, spelt B R O C H.
Our modern globes are based upon political boundaries and geographical topography yet they had geometrical predecessors which described the world as an image, a diagram or schemata. By some act of intuition, an original Idea for the form of the Earth had become established as a simple two-dimensional geometry, very like eastern mandalas.
Such a diagram came to be built into the Cosmati pavement of Westminster Abbey, this installed during the reign of Henry III as a gift from the Pope and one or more Cosmati master craftsmen. It was dedicated to the Saxon King (and Saint) Edward, the Confessor. This exotic pavement became the focus for the Coronations of subsequent English then British monarchs. Its presence at the heart of English then British king-making is part of what is called the Matter of Britain, one of many Mysteries as to the meaning of its design.