The position of the sun

First, determine the direction on the ground plane.

Generally speaking, we use the "cross" direction, that is, "up north and down south, left west and right east". However, if you encounter a map with a latitude and longitude net or a map pointing to the target, a certain direction on the "cross" coincides with the direction on the map with a latitude and longitude net or a map pointing to the target, because they are consistent in some aspects. Therefore, we can first determine the direction on the ground plane.

Second, determine the direction of the ground according to the direction of the sun.

Because the earth has been rotating from west to east, we see the sun rising and setting on the earth. The direction on the ground can be determined according to the rising and falling direction of the sun.

Example: Read the solar apparent motion diagram of different solar terms in Figure 1, and the point A is located in the observer's.

Fang.

Judging method: ① According to the rotation of the earth, we can know that the apparent motion direction of the sun is rising in the east and setting in the west, so we can determine the east-west direction in the ground plane, as shown in Figure 2; (2) According to the direction on the ground plane, it is judged as "upper north and lower south, left west and right east", and then the east-west direction in the cross is aligned with the east-west direction in Figure 2 to determine the north-south direction. As shown in figure 3.

Therefore, point A in this question is located in the north of the observer.

3. According to the known position of the direct point of the sun and the local latitude position, determine the direction in the apparent motion diagram of the sun; Or know the noon sun position at a certain latitude in different solar terms to determine the direction in the picture. The principle is as follows:

Observe the position of the sun at different points at noon.

latitude

North of the Tropic of Cancer

On the tropic of cancer

Between the Tropic of Cancer

On the tropic of Capricorn

South of tropic of Capricorn

Look at the direction of the sun at noon

Keep facing due south

The summer solstice is overhead, and the others are always due south.

Sometimes in the north, sometimes in the south, the highest sun height is 90.

The winter solstice is overhead, and the others are always due north.

Always due north.

Example: Figure 5 shows the apparent motion of the sun somewhere in the northern hemisphere. Please mark the direction on the ground plane in the picture and draw the trajectory of the sun with arrows.

Judgment method: ① Because this place is in the northern hemisphere, the noon sun is mainly in the south. The noon sun in Figure 5 is always in the south, from which the north-south direction on the ground plane can be determined. (2) According to the direction on the base plane, it is judged as "upper north and lower south, left west and right east", and then the north-south direction in the cross is consistent with the north-south direction in Figure 6, so that the east-west direction can be determined. According to the rotation of the earth, we can know that the apparent motion direction of the sun is rising east and setting west, so we can determine the rising and falling direction of the apparent motion of the sun, as shown in Figure 7.