When there is no accurate ranging instrument in the field, how to measure the distance with one hand

The person who is giving you a thumbs up is not necessarily complimenting you, but may also be aiming at you. When there is no accurate ranging instrument in the field, how to measure the distance with one hand? Follow along and learn!

In the field, if we don't have the tools to measure the distance, but we need to get a rough idea of the distance of the target, we can use the following methods.

1.Project Evaluation Methodology. The target estimation method is to judge the target distance based on the perceptual knowledge of the target distance.

To judge the distance based on the sharpness of the target, you can use the following formula:

250-300 meters: cracks are visible in the walls, tiles can be counted as grooves, facial features are blurred, and the color of clothes can be distinguished.

400 meters: The face is not clear, the head and shoulders can be distinguished.

500 meters: doors can be opened or closed, windows can see the window frames, men and women can be distinguished.

700 meters: The tiles look like silk, the windows see the lining. There is no difference between the left leg and the right leg of the human body, but the elbow.

1000 meters: The outline of the house is clearly visible, and the human body is usually thick.

1500 meters: The tile surface is flat, the windows are holes. Pedestrians appear to be squirming, and their movements are not yet known.

2000 meters: The window is a shadow, the door is a hole. People are like little black dots that they can't see clearly when they stop moving.

3000 meters: The houses are blurry and indistinguishable, the chimneys on the houses are still visible.

2.Methods of comparison. The comparison method determines the distance, that is, the distance to the target is determined based on the bearing of the known distance and the comparison of the ground object with the target.

When there is an object with a known distance near the target, the distance difference between the target and the object can be measured, and the distance difference can be subtracted (subtracted) from the known object distance to obtain the target distance.

When the target is between two objects at a known distance, the target is compared to the known object to get an approximate target distance.

If there is no object at a known distance near the target, you can divide the entire distance into parts, use the distance you are familiar with, and then use that distance to compare the rest. The sum of distances is the target distance.

3.Eye-jumping method.

Start by facing the target, straighten your right arm forward (about 60 cm), give your thumb up, close your left eye, and aim your right eye at the target from your thumb. Keeping your head and hands still, close your right eye while keeping your left eye looking through your thumb, and remember a point on where your gaze is pointing (the point should be at approximately the same distance from the target).

Compare using known intervals, or observe the distance between the point and the target with the naked eye. Multiply the measured interval by 10 to get the distance to the target.

Have you learned? When you learn, hurry up and practice, practice is true!

You can hold a shot put ball in your hand, because the shot put ball is very dense and heavy, and then because the ball is perpendicular to the ground, you only need to measure the distance from the ball to the ground.

I think you should have a certain amount of common sense, and you should also practice hard in your daily life, and then it is okay to measure the distance with the length of your palm.

A: I don't know how to measure distances with my hands. However, I think it's possible to measure distance by hand, after all, the length of the hand is a certain amount, and then people can measure the distance by hand.

First of all, you need to know the length of a hand, and then measure the distance according to the length of the palm, which will also be more accurate.

Distance measurement refers to the work of measuring the length of the line between two points on the ground. What is usually measured is the horizontal distance from the sail width, that is, the length of the two points connected by the line projected on a certain level. It is one of the features that determine the planar location of a ground point.

It is one of the most basic tasks in surveying work. The difference usually needs to be measured in the horizontal distance, that is, the length of the two points projected on a certain level.

Method: 1. Measuring distance: Use a measuring stick to directly measure the distance between two points.

2. Line-of-sight measurement: A method of measuring the distance between two points according to the principle of optics and trigonometry with a measuring instrument with a line-of-sight device.

3. Parallax distance measurement: use theodolite to measure the horizontal angle of the fixed-length baseline ruler, and use the trigonometric formula to calculate the horizontal distance between the instrument and the baseline.

4. Electromagnetic wave ranging: In the 40s of the 20th century, an electromagnetic wave rangefinder appeared, which was used to measure distance, with a long range, high ranging accuracy and high work efficiency, so electromagnetic wave ranging has become an ideal method for measuring distance.

You can choose a meter ruler measurement tool, or you can use step measurement and visual inspection to estimate it.

Analysis] This question examines three commonly used methods for measuring distance, which belong to the basic knowledge. The length of an object can be measured with a scale, a commonly used unit of length.

There are millimeters, centimeters, decimeters.

meters, kilometers; The three commonly used methods for measuring distance are tool measurement, step measurement, and visual inspection, and the answer can be solved accordingly.

1. Measurement of length: The measurement of length is the most basic measurement, and the most commonly used tool is a scale.

2. Correctly use the scale scale, scale, and graduation value.

Pay attention when measuring with a ruler:

1. The ruler should be placed along the measured length, and the edge of the ruler should be aligned with the measured object, which must be placed in a positive and overlapping manner, and should not be skewed.

2. Do not use the worn zero tick mark, such as taking another whole tick mark as the zero tick line due to the wear of the zero tick line, do not forget to subtract the tick value that replaces the zero tick line in the final reading.

3. The thick ruler should be placed vertically.

4. When reading, the line of sight should be perpendicular to the ruler surface.

To sum up, there are two types of methods: first, direct distance measurement; 2. Indirect measurement distance;

The direct measuring distance includes: 1 tape measure, 2, steel measuring distance, etc.;

Indirect measurement distance includes: 1. line-of-sight measurement, 2. Sight interpolation measurement, 3. Electromagnetic wave measurement, etc.;

The advantages of direct distance measurement are: the method is simple; The disadvantages are: affected and limited by terrain and length;

The indirect distance is not limited by the terrain, the labor intensity is low, and the efficiency is high; The disadvantages are: there are more requirements for facilities.

Straighten your arm forward and raise your thumb, close your left eye, your right eye, thumb, and target form a straight line, close your right eye, open your left eye, remember the point on the right side of the target with your left eye and thumb extending the straight line, visually measure the distance between that point and the target, and multiply by 10, which is the approximate distance you are to the target.

Thumbs up. The arm is flat, the gaze is about 120 dense positions with the horizontal line through the fingertips, and the target height is estimated by looking at the height of the target, and the angle between the two realized sight lines passing through the top and bottom of the target is how many dense positions, and the dense position is multiplied by the target height (based on experience) is the target distance.

For example, the Japanese soldier was about 100 meters tall and had a distance of 150 meters from a distance of about 100 meters between the top of his head and the soles of his feet.

This geometry is introduced. Since the length of some object is usually a known quantity, such as a car, a house, etc., the distance can be calculated based on how much angle it occupies in visual inspection (a dense position is used in military surveys). The number of points in the area covered by the thumb with the arm straight is fixed, and this angle value can be obtained by referring to the target being measured.

After conversion, you can get an approximate data for the distance.

The secret position is a circle divided into 6000 parts, each part is a secret position, and stretch out the right hand, close the left eye, aim at an object, let him just next to the left side of your thumb, do not move the hand to change the eye, you will find that the object produces a jump of a distance, according to the visual width of the object, the width of the jump, the ratio is multiplied by 50for the approximate distance. There is also the accumulation of experience,.

The secret calculation is also the approximate distance of the actual object in your hand by calculating the corresponding number of secret positions.

Theoretically, with the arm straight, the thumb up, and similar calculations based on the distance from the eye to the thumb (about the length of the arm), the length of the thumb, and the height of the object being measured. But in fact, when using this skill, it is basically based on empirical ranging, and it takes a long time of practice to become proficient. Moreover, it should be corrected that finger ranging is mostly used for rough measurement of marching and artillery positioning, and it is compulsory for every soldier.

Snipers rarely use finger ranging, because finger ranging has to stretch the arm straight, which is easy to expose themselves, and snipers mostly use direct visual inspection. Finger ranging can generally be estimated 2-4 kilometers (applicable when there are obvious features, such as houses, trees, etc.), experienced soldiers have an error of no more than 200 meters, and visual measurement is generally used to estimate the distance within one kilometer, with an error of less than 50 meters.

Finger ranging and visual inspection require long-term practice, as well as an understanding of the size of general ground objects, their visual sizes at different distances, and the ability to skillfully use reference objects with known distances for comparison. If you can practice hard, I believe you will succeed.

Visual distance method: A simple way to measure distance with your fingers and eyes.

Khan, the visual inspection, the accurate, the instrument sellers are not all out of business

The eye-jumping method commonly used in the military The eye-jumping method is an estimated measurement by estimating the width of the field seen by the eyelet. Based on the distance between the two pupils about one-tenth of the length of one's own arm, multiply the width of the measured object by 10 to determine the distance from the standing point to the target. The measurement is as follows:

1. Raise our right arm horizontally, make a fist with our right hand and raise the thumb 2. Use the right eye (left eye closed) to overlap the left side of the thumb with the target in a straight line; 3. If the right arm and thumb do not move, close the right eye, and then observe the left side of the thumb with the left eye, you will find that the edge line is a distance away from the right side of the target; 4. Estimate this distance (this can also be measured), and the distance is 10, and the number is the approximate distance between us and the target.

Answer]: B2020 version of the textbook p48

Total station, also known as total station electric slip Changzi speed tester, is an instrument that can simultaneously measure the angle of the letter and the distance, and is composed of three parts: electronic rangefinder, electronic theodolite and electronic record cavity meditation.

Then the auspicious trace answer]: b

2021 2020 Edition Textbook P80

Once the total station is observed at the station, the necessary observation data such as oblique distance, zenith distance, vertical angle, horizontal angle, etc. can be automatically displayed, and almost at the same instant, the coordinates and elevation of the cave to the horizontal distance, elevation difference, and point can be obtained. If the data terminal collected by the total station field is connected with the computer and plotter through the transmission interface, and the data processing software and drawing software are matched, the automation of mapping can be realized.

Answer]: a, b, c

A, B, C analysis: The key wheel has a certain degree of professionalism, for candidates who do not have similar engineering practical experience, there is a certain degree of difficulty, mainly to assess the basic functions of commonly used measuring instruments.

First of all, we all know that theodolite and total station can directly measure the horizontal distance between two points. In fact, the level uses the principle of line-of-sight measurement, and it can also measure the approximate horizontal distance between two points, but the measurement accuracy is not high.

The leveling ruler can only measure the levelness, and obviously cannot measure the distance; A tape measure can measure the distance between two points, but it is not possible to measure the horizontal distance between two points.

Therefore, the correct choice for this question should be "a, b, c".