What is Zhang Zhixin's formula?

Zhang Zhixin's formula is the relationship between the normal line and the parallel circle between two points at the same latitude. On the rotating ellipsoid, two points with different latitudes intersect with the short axis of the ellipsoid in different places, and the normal sections of the two points with higher latitudes are often lower than those of the two points with lower latitudes, so the normal sections of the two points do not overlap, which is called relative normal section.

When two points on an ellipsoid are at the same latitude, the relationship between their relative normals and parallel circles passing through these two points. Because the normal and short axis of a point at the same latitude intersect at a point, the two relative normal sections are completely coincident.

Zhang Zhixin is actually Ruoyun Zhang's grandfather and a famous geologist in China. In the past, there was a formula named after him in the field of surveying and mapping, which was called "Zhang Zhixin formula".

Ruoyun Zhang:

Ruoyun Zhang, 1988, was born in Beijing on August 24th. He is an actor from mainland China and graduated from Beijing Film Academy. In 2004, he participated in his first TV series "vows of eternal love".

20 1 1 Starring in the inspirational revolutionary drama "Black Fox" and singing the ending song "Strong Man". With the role of Fang Tianyi in the play, he won the most popular TV newcomer award and the best TV newcomer award in the second LeTV Film Festival.

20 13 starred in the war drama "The Strong Years of Snow Leopard". In 20 14, he won the National Drama Festival Outstanding Actor of the Year Award.