The solution to the problems in the calculation of land area 1. Improve measurement accuracy in the field and avoid measurement errors. In the field of land measurement, the system should first avoid system errors, human error and error factors, in addition to the use of high-precision control data, to comply with the professional procedures, taking into account external influences, improve the measurement accuracy, so as to ensure the accuracy of land area measurement. In the determination of land area, the instrument we often use is an area measuring instrument. It uses the GPS global positioning technology to calculate the area of ​​the measured land. When the area measuring instrument is used for the land area of ​​the farmland, there are different names such as the acremeter and the harvester area measuring instrument. These names are named through the use of the area meter. Upon hearing this name, you can understand the scope of use of the area meter. 2. The following three methods are used to solve the distortion caused by the map projection: (1) A mathematical model is established by using the radius of the earth and the distance from the central meridian, and the projection area is corrected; (2) The appropriate projection bandwidth is selected. The distortion produced in the map projection varies with the bandwidth. Therefore, when calculating the area, first calculate the maximum length deformation value based on the known area accuracy, and then determine the projected bandwidth from this length deformation value, so as to select the banding; (3) Use equal-area projection method. The distortion produced in the map projection is due to the isometric projection of the Gauss-Krueger projection. When calculating the area, to ensure that the area does not change, consider using the equal-area projection method to calculate, that is, to calculate the starting latitude and longitude and the area of ​​the ending latitude and longitude. Since the enclosed area is a trapezoid after Gaussian projection, it is also called spherical trapezoidal area. Calculations. 3. Inclining the projection of the ground surface onto the plan to produce a correction of the deformation. In the area calculation, the deformation resulting from the projection of the inclined surface onto the plane must be properly considered. The tilted surface projection area is related to the inclination of the ground and should be corrected when calculating the actual area in the field. 4. Two methods to eliminate unreasonable adjustments in the area of ​​multiple parcels. (1) The method of weight adjustment. According to the measurement error theory, when the area is the same, the weight of the parcel with large area error is small; when the area error is the same, the parcel of land with large area is also large. After the land rights have been determined, we can use the area closing difference between the sum of the total area and the total area measured and controlled values ​​to calculate the second estimated value of the area's weighted level difference and area error, so that multiple area area adjustments can be made. It is more reasonable. (2) Press precision adjustment method. In the cadastral mapping and area measurement, in order to get rid of the impact of control error propagation and projected deformation on the measured area accuracy, in order to take into account both the size of the plot area and the real estate price of the plot in the area adjustment, it can be ensured. Adjustment method for area accuracy requirements. For example, in the urban areas, the measurement accuracy of the area of ​​the ownership units is relatively high, and the calculation accuracy of the public-owned land areas owned by the cities and towns such as streets, roads and roadways is relatively wide. Therefore, we can guarantee the area accuracy of the parcels and neighborhoods, allocate the closure of the control area to the areas of public land such as roads and roadways, and maintain the area of ​​each ownership unit unchanged, thereby improving the parcels and streets. Square area of ​​the measurement accuracy. This method not only does not affect the quality of cadastral mapping, but also improves the accuracy of the main content of cadastral maps. electrical monitoring window,cable junction box,waterproof enclosure,Network enclosure wybox inc. , https://www.wybox-inc.com