The relationship between ternary and twenty-eight stars

I looked it up and thought it was two different methods. . .

Three walls:

The ancients divided the sky at the north celestial pole seen on the earth into Ziweiyuan, Taiweiyuan and Tianshiyuan.

So ternary refers to Ziweiyuan, Taiweiyuan and Tianshiyuan. Sanyuan has become the main body of three sky regions, and these sky regions are also named after Sanyuan.

Ziweiyuan: the place where the emperor lived.

Tai Weiyuan: It seems to belong to a courtier.

Timing refers to the market.

Eighteen stars:

The ancients divided each elephant into seven nights, so four elephants had twenty-eight nights.

At first, the ancients chose 28 stars to compare the movements of the sun, the moon, gold, wood, water, fire and earth as observation marks. The meaning of "lodge" is similar to the "palace" of the zodiac, which means constellation. Represents the position of the sun, the moon and five stars. In the Tang Dynasty, Twenty-eight Hostels became the main body of the twenty-eight celestial bodies, and these celestial bodies were still named after Twenty-eight Hostels. Different from Sanyuan, as a celestial body, Twenty-eight Hostels are mainly used to divide the ownership of star officials.

Seven lodging houses in the East: horn, sound, interaction, room, heart, tail and dustpan;

Seven Western hostages: Kui, Lou, Wei, Chang, Bi, Gou and Shen.

Seven nights in the south: essence (cave essence), ghost (Yu ghost), willow, star (seven stars), Zhang, wing and Yi.

Seven nights in the north: fighting, cows, women, emptiness, danger, houses (barracks) and walls (east walls);

Twenty-eight nights are four elephants.