The concept of measurement

It is a subject that studies the use of electromagnetic wave sensors to obtain image data of targets, extract semantic and non-semantic information from them, and express them in the form of graphics, images and numbers. Its basic task is to process, measure and interpret photographic photos or remote sensing images to determine the shape, size and position of objects, and then make maps. According to the different ways of obtaining images and remote sensing distance, this subject is divided into ground photogrammetry, aerial photogrammetry and space remote sensing measurement. Definition 1: Engineering survey is a subject that studies all kinds of survey work in the planning, design, construction and operation management stages of various projects.

Various projects include: industrial buildings, railways, highways, bridges, tunnels, water conservancy projects, underground projects, pipeline (power lines, oil pipelines) projects, mines and urban construction. General engineering construction is divided into three stages: planning and design, construction and operation management. Engineering survey is to study all kinds of survey work carried out in these three stages.

Definition 2: Engineering survey mainly studies the theories, methods and technologies of terrain and related information collection and processing, construction lofting, equipment installation, deformation monitoring, analysis and prediction, as well as the management and utilization of surveying and engineering related information in various stages of engineering, industrial and urban construction and resource development. It is the direct application of measurement in national economy and national defense construction.

Definition 3: Engineering Surveying is an applied discipline that studies the theory, method and technology of measuring and describing specific geometric entities in the earth space (including ground, underground, underwater and air) and realizing the layout of abstract geometric entities. Mainly in construction engineering, machinery and equipment. It is a subject that studies the theory, method and technology of how to draw the related information such as features and landforms in local areas of the earth's surface into topographic maps. Topographic mapping can be divided into analog mapping and digital mapping according to different mapping methods.