How do I measure the latitude and longitude in local time and the height of the sun at noon? 5

The following is for reference, the height of the sun at noon can be measured by observing the shadow of the object, such as a 1 meter long bamboo pole vertically inserted into the ground, at this time the shadow length is x meters, then the pole and the shadow are perpendicular to each other to form two straight sides of a right triangle, the end point of the shadow and the fixed point connection of the bamboo pole is the hypotenuse of the right triangle, and the angle between the shadow and the hypotenuse is the sun height angle at this timetan = pole length The greater the shadow length of the sun height angle, the shorter the shadow of the bamboo pole. Longitude calculation:

At noon, the height of the sun is the largest of the day, the shadow is the shortest, measure the change of shadow length in a few hours before and after noon, when the shadow is shortest is 12 o'clock at noon in the local place, and record the Beijing time displayed by the watch at this time, Beijing time is the time of the East Eight District, that is, when the east longitude is 120 ° east, according to the time difference between the local and 120 ° east longitude, (the longitude difference is 15 ° time difference of 1 hour; 4 minutes for every 1° difference in longitude) calculates the difference in longitude between the local and 120° east longitude, and further determines the local longitude based on the fact that the east side of the earth is always earlier than the west time, i.e., the time passes faster. Latitude calculation: When the shadow is the shortest, the sun height is the maximum of the day, and the local time is 12 o'clock at this time, and the sun height at this time is the noon sun height of the day, using the solar height formula:

In order to accurately know the latitude of the direct point, you can choose the winter solstice (the sun directly reaches 23°26 south latitude) or the summer solstice (the sun directly reaches 23°26 north latitude), or the spring or autumn equinox (the sun directly reaches the equator).

There are two ways to determine the solar altitude angle at noon:

Simple height calculation method。Take a semicircular protractor and a plumb line, at noon, take the north-south direction, use the sunglasses to the naked eye along the straight edge of the protractor and the sun in a straight line, fix the protractor, at this time the plumb line and the straight edge of the protractor have an angle z, use the formula: h=90-z to find the sun altitude angle h.

Immediate results。Take a long bamboo pole and stand on the flat ground, from one hour before noon to one hour after noon, draw a point on the ground at the top of the rod shadow every 15 minutes or so, and finally connect all the points into a line to form an arc; Take the shortest distance between the bottom of the rod and the arc a, measure the length of the rod b, and the noon sun height angle h can be found by the following formula: the h value can be accurate to the minute.

When the shadow is the shortest, the height of the sun is the highest of the day, and the local time is 12 o'clock local time.

The altitude is the height of the sun at noon on the day, using the solar height formula:

In order to accurately know the latitude of the direct point, you can choose the winter solstice (the sun directly reaches 23°26 south latitude) or the summer solstice (the sun directly reaches 23°26 north latitude), or the spring or autumn equinox (the sun directly reaches the equator).

The formula for calculating the height of the sun at noon:

h 90° h is the altitude of the sun at noon, which is the local latitude, and δ is the latitude of the direct point of the land difference).

In the formula, always take a positive value, δ take a positive value in the local summer half year, and take a negative value in the winter half year. Between the Tropic of Capricorn, at 90°H, the altitude of the Sun at noon is 180° h

There are two ways to determine the solar altitude angle at noon:

Simple altimeter hyomin algorithm。Take a semicircular protractor and a plumb line, at noon, take the north-south direction, use sunglasses to the naked eye along the straight edge of the protractor and Tai Na Shen He Yang into a straight line, fix the protractor, at this time the plumb line and the straight edge of the protractor have an angle z, use the formula: h=90-z to find the sun altitude angle h.

Immediate results。Take a long bamboo pole and stand on the flat ground, from one hour before noon to one hour after noon, draw a point on the ground of Li Pai at the top of the rod shadow every 15 minutes or so, and finally connect all the points into a line to form an arc; Take the shortest distance between the bottom of the rod and the arc a, measure the length of the rod b, and the noon sun height angle h can be found by the following formula: the h value can be accurate to the minute.

This is the formula for calculating the noon solar altitude angle: noon solar altitude angle 90 degrees local latitude direct point latitude (the principle of taking the value of the local latitude and the latitude of the direct point: the northern hemisphere takes the positive value, the southern hemisphere takes the negative value) i.e.:

The latitude of a certain place, the altitude angle of the sun at noon, and the latitude of the direct point of the sun on that day, as long as you know any two of the three conditions, you can find the third The two latitudes mentioned in your question: When you find the altitude angle of the sun at noon on a certain day and a place, the latitude of the earth refers to the latitude of the place you are looking for, and the latitude of the direct sun point refers to the latitude of the direct sun point on the day you are seeking. The ** of these two values can be diverse, taking the third year of high school as an example, you can give it to you in the question stem, or you may use the latitude in the diagram to read, and you may need to deduce through some special conditions, so it is not good to generalize.

For example, there are a few special conditions: during the spring and autumn equinoxes, the latitude of direct sunlight must be 0 degrees, the winter solstice must be at 23 degrees 26 minutes south latitude, and the summer solstice must be at 23 degrees 26 minutes north latitude. If it weren't for these special dates, then the question would definitely give the conditional song branches, which can only be deduced through the conditions).