1. Field data collection in the "measured law" The basic idea is: in the field data collection, the use of total station with the polar coordinate determination of the appropriate number of "broken the Ministry of the basic points", and then semi-equipment Act (only measured direction) , Kan Zhang method (only measuring distance) measured as part of the Department of broken point position (coordinates), and finally take full advantage of a straight line, right angle, parallel, symmetry, geometry, etc. all in the house (or spot) to calculate all the broken point of the Ministry of coordinate. Can also be directly in the surveying and mapping software, mapping environment, draw the graph.

2. Polar coordinate method
Polar coordinate method is to measure the broken point of the most commonly used method of the Department. As shown below, Z is the measured sites, O asked for the fixed point, P for the question of point. A good placement in the Z-point apparatus, the amount of equipment to take high-i; awarded O points, reading the direction of orientation points, O, the value of L0, (often configured to zero, the following settings to point the direction of the value of zero), and then seek to be awarded Point P quantity take spy elevation (lens height) to read the direction of the value of LP, and then measure the Z to the P-point between the distance (slant range) SZP and the vertical angle α (a large majority of total stations, said T zenith distance), T = 900-α, is to be determined point coordinates and elevation can be obtained the following formula:


Where: αZP = αZO-LP
3. To determine an angle point, because of its vicinity (3m inside) has obstructions can not use the direct determination of polar coordinates, what methods can be measured?
Awarded eccentric method according to the description of the method can be applied to the determination. That is, when demand point and the measurement site, to be unreasonable or impossible, as the legislation mirrors, they can use the Indirect Determination of broken eccentric awarded points under the Ministry of the Act, including a straight-line extension of eccentric law, parties asked to extend the law and the vertical eccentric eccentric method.
4. All Instruments Act
(1) The polar coordinate method
(2) awarded eccentric method
5. Data coding concepts: field data collection only geodetic instruments total station or other measurement point broken the Ministry of the location (coordinates) is a computer automatically into the map can not meet the requirements must also be a connection point of the relationship between surface features and ground object attribute information (surface features type, etc.) recorded. Tends to be used according to certain rules constitute a string of symbols to represent features in the relationship between properties and connection information such as rules that have a certain string of symbols is called data encoding.
Data encoding basic elements: surface features elements of coding (or the signatures, said surface features, the feature attribute codes, the feature code), the connection between yards (or the connection point number, the connection number, connection linear), surface-like surface features Fill codes.
Topographic coding design should follow the principles of: (a) comply with State Plotting-style classification, in line with topographic maps mapping rules; (2) concise, easy to operate and memory, more in line with the habit of surveyors; (3) to facilitate computer processing; (4) GIS software such as ease of use.
Encoding type: At present, the domestic development of mapping software has been a lot are generally in accordance with their needs, work habits, equipment and data processing methods to design their own data coding scheme, have not formed a fixed standard. Data encoding and input methods from a structural distinction between the elements is mainly a full-coding, block-structured code, simple encoding and two-dimensional codes.
1, all elements of coding schemes: All elements of the Department of coding required for each broken point should be a detailed description. Total factor codes are usually composed by several decimal number. Each one figures are according to different levels, have a specific meaning.
If a broken encoding 20,101,503 Department of points, you figure the following meanings: the first number (2), said: topographical element classification; second and third digits (01), said: topographical element sub-categories; fourth, fifth and sixth digits (015), said: class number; seventh and eighth digits (03), said: feature point number.
2, no memory coding system: in surveying and mapping system, each of a feature-coding and its schematic symbols and instructions are prepared in a Chinese character tiles, the formation of a schematic symbol code table stored in the computer, if only the the press of a key, code table can be displayed; light pen or click of the mouse in the desired symbol, the encoding will automatically give as gifts survey record, users do not need memory encoding, you can always check
3, block structure coding scheme
4, non-coding system: external industry is not encoded by the corresponding symbol icon or menu one level index, from within the system is converted to code. This method though not necessarily to memory encoding, but each time go one level search icon in the menu too complicated, in addition, the digital mapping workers is concerned, the concept of coding is not detrimental to subsequent processing.
5, two coding schemes
6. The use of total station to carry out large-scale outdoor digital mapping, the operating mode can be divided into test notation and e-plate method.
7. Brief Determination of broken test in mind the Department of points operation.
     Determination of measurement in mind the Department of point of operation broken as follows:
     (1) into the test zone, painted sketches collar mirror (feet) stations around the first member of the terrain, the feature distribution is probably read, and a sense of direction, according to the approximate percentage of time a hook decorated with the major surface features, topography sketches (if the old map in the amplification would be more accurately identified), to facilitate observation measured in the sketch marked the location of the points of broken and dot.
     (2) Instrument observer member of the command mirrors legislation to pre-selected to prepare a known point on the mirror legislation orientation; own good fast-rack instrument, the connection of electronic hand-book, take the amount of equipment is high; and then start the operation of total stations and electronic hand - book, select the measurement of the state, enter the test site, number and orientation-point number, the starting point of the direction of orientation value (usually the initial direction with a value of zero) and equipment is high; aiming directional prism, will be a good direction, lock the total station dial, to inform those who began to run point of mirror legislation.
     (3) Legislative members of the broken mirror prism of the points of legislation, the observer in time aiming prism, using walkie-talkie link to determine the mirror height (usually located at a fixed height, such as 2.0m) and the legislative point of the nature of the input Mirror high (high mirror the same press enter key), the feature code (no code when operating directly on the Enter key) to confirm an accurate prism awarded later, then e-book on the enter key in hand, to be e-Hand Book issued ringing sound, it is clear measuring point data has entered the e-book in hand.
8. Measuring the basic work is to determine the point and the traditional method is to use instruments measured the three-dimensional coordinates of points, or measurement of horizontal angle, vertical angle and distance to determine the point position, and then draftsman by coordinates (or the angle and distance) will point plotting to the drawings. Run-foot member of the drawing according to the actual terrain to the inspector's report What is the point of measurement (such as angle points), the (angle) of what should be (angle) of connections, etc., draftsman is based on plotting the points on the spot position according to schematic symbols to surface features (Housing) portrayed. So bit by bit measurement and painted, thus generating a topographic map.
  Digital Mapping mapping information must be collected, which includes point location information, connectivity information and attribute information for digital mapping not only to determine when the topographic point position (coordinates), but also know what the point is that the road or housing, note the spot of the measuring point of coding and connection information, displayed as a diagram using the Mapping System schematic symbol library, as long as know the code, you can know from the library transferred out with the coded symbols corresponding to schema mapping .
9. Brief electronic flat-panel field data collection method
(1) the use of computer measurement areas of known control points and the measured coordinates of the site transferred to the total station's memory, or manual input control points and measuring the coordinates of the site to the total station's memory.
(2) a good test site, equipment shelves, and to a laptop or PDA and Total Station with the corresponding cable connection is good, boot entered the Surveying and Mapping System; setting up total stations of communication parameters; selected by the use of full stops instrument type. Respectively, total station and notebook computer or PDA to complete the station, directional point setup.
(3) The total station broken awarded the Department of points, the use of computer-controlled total station measuring angle and distance measurement, each measuring finished a point, the screen will prompt plotting displayed.
(4) According to the type of measured point, in the surveying and mapping system to find the appropriate action will be drawn out of the measured points, on-site mapping.