In practical use, such as measuring angle or distance, when the measuring point is far away from the measured object, the measured object (such as a flower tower ruler) can be stuck between two vertical wires at this time.
It doesn't matter even if there is a slight deviation in alignment. Because of the long measuring distance, the error angle of actual conversion is very small, which can be ignored in the calculation results. Align the measured object with the axis, that is, the two methods I mentioned above, or align with the intersection of 10. According to personal habits, old surveyors should not be limited to using the 10 junction.
Extended data:
The support is simple in structure and low in cost. It is mainly used with ground telescopes (geodesy, bird watching, etc.). ). If it is used to observe celestial bodies, the direction of the celestial bodies' diurnal motion is usually not vertical or parallel to the horizon.
Therefore, it is necessary to rotate two axes at the same time and change the rotation speed with time to track the celestial body. However, other celestial bodies in the field of view will rotate relative to the target celestial body, and unless a mechanism is added to counteract the rotation of the field of view, it is not suitable for celestial photography with long exposure.
Application of enumeration (the coordinates of point A and point B are known, and the coordinates of point C are obtained);
Set up an instrument at one of the two points A and B with known coordinates (take the instrument set up at point A as an example), aim at another known point (point B) after completing the basic alignment operation, then configure a reading 1 according to your own needs and record it, and then aim at point C (unknown point) to read reading 2 again.
The difference between reading 2 and reading 1 is the angle value of angle BAC, and then by accurately measuring the distance between AC and BC, the precise coordinates of point C can be calculated mathematically.
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