Measure the measurement conditions?

<1> Briefly describe the tasks and functions of surveying (engineering surveying).

1, the task of measurement

Its task has three aspects:

①

<1> Briefly describe the tasks and functions of surveying (engineering surveying).

1, the task of measurement

Its task has three aspects:

① To study and determine the shape and size of the earth and provide necessary data and information for earth science;

② Drawing the features and landforms of the earth's surface;

(3) Arrange the design results on the drawings to the site.

2, the role of measurement

(1) First of all, in the engineering design, provide drawings and materials, define the coverage, understand the surrounding projects, and find out whether there are urban underground pipelines within the coverage, and whether it will affect the exploration and mechanical facilities. If there is no topographic map and pipeline detection map of various scales brought by engineering survey, engineering design will become a cook without rice.

Secondly, in the process of construction, the first step of the project is the on-site positioning and lofting of buildings and structures, because it is impossible to find a place to put buildings casually. According to the purpose and technological process of a building or different parts of the same building, its accuracy requirements are inconsistent and often vary greatly. At this point, the accuracy requirements of engineering building positioning should be correctly formulated. If they are set too wide, quality accidents may occur. On the other hand, if the setting is too strict, it will bring many difficulties to the lofting work, thus increasing the lofting workload and prolonging the lofting time, which does not meet the needs of modern high-speed construction.

(3) Finally, determine the accuracy of building lofting. The positioning error when the building is completed is caused by construction error and survey lofting error. Because different buildings or different parts of the same building have different requirements for lofting accuracy, it is necessary to consider the construction site conditions and construction procedures and methods, and analyze whether these buildings must be directly lofting from control points. For some building components, although their relative position accuracy is very high, they can be directly set out by using their geometric relationship.

What is the basic principle of measurement?

The measurement work must follow the principle of "whole first, then parts, then broken parts, from high to low" to organize and implement. Considering all aspects of the survey area comprehensively, several points that are beneficial to detail measurement are laid out, and then the measurement of the broken area is carried out according to these points, so that the accumulation of errors can be reduced and the accuracy in the survey area can be uniform.

(2) Extended reading of measurement conditions:

Measurement is to describe the observed phenomena with data according to certain laws, that is, to describe things quantitatively. Measurement is the quantization process of non-quantized objects.

In mechanical engineering, measurement refers to the experimental cognitive process of comparing the measured value with the standard quantity with the measuring unit, so as to determine the ratio between them.

Four elements

1. The measured object is the measured object:

Mainly refers to geometric quantities, including length, area, shape, elevation, angle, surface roughness and form and position error. Because geometric quantities have various types and shapes, it is necessary to study and be familiar with their characteristics, definitions and standards of measured parameters when measuring.

2. Measurement unit:

China's the State Council reiterated in Article 3 of "People's Republic of China (PRC) Metrology Management Regulations" (for Trial Implementation) issued on May 27th 1977: "China's basic metrology system is metric, and the international system of units is gradually adopted.

1984 On February 27th, People's Republic of China (PRC) (PRC) officially announced the legal units of measurement, and the metric system was determined as the basic measurement system in China. In length measurement, the unit is meter (m), and other commonly used units are millimeter (mm) and micron (micron). In angle measurement, the units are degrees, minutes and seconds.

3. Measurement method:

Refers to a logical sequence of operations described by classes used in measurement. The measurement of geometric quantity is based on the characteristics of measured parameters, such as tolerance value, size, weight, material, quantity and so on. And analyze the relationship between this parameter and other parameters, and finally determine how to measure this parameter.

4. Measurement accuracy:

Refers to the degree of consistency between the measured results and the true values. Because any measurement process will inevitably produce measurement errors, large errors indicate that the measurement results are far from the real values and the accuracy is low. Therefore, accuracy and error are two relative concepts. Due to the measurement error, any measurement result is expressed as an approximation.

(3) Psychometrics

Dear, if you have money at home, fly to Shanghai and ask why you wrote back in the first place.

There is no money at home, so I can't go to Shanghai, so I have to study by myself.

No one will answer this question for you.

Psychometrics is not the focus of this book, it just tells you some basic theories. Why are you trapped here?

Honey, don't study hard and don't stick to details.

It is necessary to know what the purpose of studying psychometrics is. Study with goals, don't dig books!

Adopt me, dear.

What is the fundamental task and work of surveying?

Basic tasks and functions of surveying

Control survey is a subject that studies the precise determination and description of the spatial position of ground control points and their changes. It's big.

It is based on the basic theory of geodesy, taking engineering construction survey as the main service object and serving human society.

Activities provide useful spatial information. Therefore, in essence, it is a discipline of geo-engineering information, an earth science and

As an important branch of surveying and mapping, it is a basic and applied discipline in engineering construction survey.

It plays an important role in cultivating surveying engineering professionals.

The service objects of control survey are mainly various engineering construction, urban construction and land planning management.

This determines that its measurement range is smaller than that of geodesy, and it is also diverse in observation means and data processing methods.

Cultural characteristics.

As the service object of control survey, engineering construction can be divided into design and construction in the process.

And operation. Each stage puts forward different requirements for control measurement, and its basic tasks are as follows:

1. Establish a surveying and mapping control network for surveying and mapping large-scale topographic maps in the design stage.

At this stage, designers should design buildings or planning areas on large-scale topographic maps.

So as to obtain the data on which the design is based. Therefore, the task of control survey is to lay out the mapping control as the basis of the root control.

Network to ensure the accuracy of topographic maps and the accurate splicing between topographic maps. In addition, for real estate, this kind of

Surveying and mapping control network is also the basis of corresponding cadastral survey.

2. Establish the construction control network in the construction stage.

At this stage, the main task of construction survey is to set out the buildings designed on the drawings to the site.

For different projects, the specific tasks of construction survey are also different. For example, the main task of tunnel construction survey is to ensure that

The tunnel excavated in the opposite direction can be penetrated with specified precision, and the building can be built according to the design position; Lofting process

The direction and distance marked by the instrument are calculated according to the control network and buildings designed on the drawings.

Therefore, before construction lofting, it is necessary to establish a construction control network with necessary accuracy.

3. In the operation stage after the completion of the project, establish a special deformation observation control network to monitor the deformation of the building.

Because the original state of the ground is changed in the construction stage, and the weight of the building itself will cause the foundation.

And the uneven changes of the surrounding strata. In addition, the building itself and its foundation will also be produced due to the change of foundation.

Deformation, this kind of deformation, if it exceeds a certain limit, will affect the normal use of buildings and even seriously endanger them.

Safety of buildings. In some big cities (such as Shanghai and Tianjin in China), due to the over-exploitation of groundwater, it will also

Causing large-scale land subsidence in urban areas, thus causing harm.

Therefore, in the operation stage after completion, it is necessary to have this kind of

Deformation monitoring of suspicious buildings or urban areas. Therefore, it is necessary to set up a deformation observation control network. Due to this deformed value

Generally speaking, they are very small. In order to measure them accurately enough, the deformation observation control network is required to have high accuracy.

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Is it engineering survey or hydrological survey?

The former is an engineering method that uses measuring instruments such as steel ruler, level, theodolite and total station to survey the actual terrain or set out the design drawings to the field, while the latter is an engineering method that observes hydrological data and makes analysis and statistics to manage the reservoir.

What is the correct measure of Lu?

Definition of weight in measurement

Variance is the absolute numerical characteristic of accuracy. An observation condition corresponds to a certain error distribution, and the certain error distribution corresponds to a certain variance (or mean error). In order to compare the accuracy between the observed values, besides the variance, the accuracy between the observed values can also be measured by the proportional relationship between the variances. This numerical feature represents the proportional relationship between the variance of each observation, which is called weight.

Weight is a relative numerical characteristic of accuracy and plays an important role in adjustment calculation. In practical surveying, the absolute digital feature (variance) of accuracy is often unknown before adjustment calculation, but the relative digital feature (weight) of accuracy can be determined according to the given conditions in advance, and then the absolute digital feature (variance) representing accuracy can be estimated according to the adjustment results.

What is the difference between surveying and surveying in the specialized course of Qi?

Surveying refers to a specialized course, so surveying and mapping here >; Measurement, for the following reasons:

Measurement is to obtain data from the field and process the data into a map, which is calibration; According to the existing position on the right side of the map, mark it on the spot. This is the layout.

Surveying and mapping is to obtain data and provide applications after describing and processing it.

Surveying and mapping majors are divided into three major directions: geodesy and surveying engineering, photogrammetry and remote sensing, cartography and geographic information engineering. These three directions can not only do academic research, but also provide practical applications.

What is measurement? What is the task of measurement?

Surveying is a science that studies the shape and source size of the earth's sphere and determines the ground points. It is a science and technology that studies the collection, processing, management, updating and utilization of information related to geographical spatial distribution on the whole earth and various natural and man-made objects on its surface and outer space.

Its main task has three aspects:

First of all, study and determine the shape and size of the earth to provide necessary data and information for earth science.

The second is to draw the features and landforms of the earth's surface.

The third is to design the design results on the drawings to the site.

"Nine" surveying and mapping project, surveying and mapping, seeking detailed explanation, clear steps, thank you.

This is a question of conditioning. There are two redundant observations in this question, and two conditional equations can be listed. Under the condition that [PVV]= the minimum value, three correction numbers can be obtained and the elevations of n points can be calculated. Then, according to these three corrections, the mean error of unit weight can be calculated, and then the mean error of N-point elevation can be calculated.

The above contents can be done step by step according to the steps in the adjustment book. The direct algorithm and answer are as follows:

The elevations of the n points in the table are calculated according to a single leveling route, and the elevations of the n points are calculated from ABC respectively. There are three different results, and then the elevations of the n points are calculated as 4 15.044 according to the weighted average.

In order to evaluate the accuracy, it is necessary to calculate the correction number V of the elevation difference of three sections according to the elevation of N point, the elevation of ABC point and the observed elevation difference. The weight of each section is calculated as P= 1/S, and the pvv is calculated separately, and the total is [pvv]=62.5.

The unit weight error = [pvv]/(n- 1) is under the root sign, where n=3, and the unit weight error is calculated as 5.59mm. 。

The unit weight error is 5.59mm, that is to say, the height difference error of 1km leveling is 5.59 mm.

Calculate the elevation of N points with three ABC data, and the sum of the three weights of N is 0.722.

According to P= 1/S and weight =0.722, which is equivalent to the horizontal route length of 1.4km, the elevations of n points are directly measured.

Therefore, the mean error in elevation of N points = mean error in unit weight * 1.4 Under the root sign, it can be calculated that the mean error in elevation of N points is 6.58 mm ..

Inconvenient to enter formulas; For the sake of clarity, please forgive my verbosity.

What is survey lofting in survey?

Surveying and mapping refers to the activities of measuring, collecting and expressing the shape, size, spatial position and attributes of natural geographical elements or surface artificial facilities, and processing and providing the obtained data, information and achievements.

Surveying studies the theoretical and technical disciplines of measuring and calculating the geometric position of ground points, the shape of the earth and the gravity field of the earth, measuring the natural shape of the earth's surface and the geometric distribution of artificial facilities, and combining with the geographical distribution of some social and natural information, compiling various scale maps and thematic maps of the world and local areas. Also known as measurement. It includes two main contents: measurement and drawing. Surveying and mapping is widely used in economic construction and national defense construction. In urban and rural construction planning, land resources utilization, environmental protection and other work, it is necessary to conduct land survey and map various maps for planning management. In geological exploration, mineral development and water conservancy and traffic construction, geological survey, control survey of various building design and construction, mine survey, route survey and topographic map must be carried out. Marching operations need military maps, as well as accurate geocentric coordinates and gravity field data to ensure that long-range weapons can accurately hit targets.

The main research object of surveying and mapping is the earth and its surface morphology. In the process of development, geodesy, general surveying, photogrammetry, engineering surveying, marine surveying and mapping and cartography have been formed.

Setting-out is to measure design points, lines or other design figures on site by conventional survey or RTK method. Commonly used methods are polar coordinate lofting and distance intersection lofting.