The software is a control measurement data processing software developed by Southern Surveying and Mapping Instrument Company, which uses Win-dons-style data input technology and a variety of data interfaces (Southern series of product interfaces, other software file interfaces), supplemented by dynamic display of network diagrams, to achieve the integration of data acquisition, data processing and results printing.The benefits of the flat-difference software are that the output is rich and powerful, diverse, and the report is complete and detailed, and the report content can be customized according to the user's needs, along with detailed precision statistics and mesh analysis information. Its interface is friendly, powerful and easy to operate.The flat difference report includes: control network attributes, control network profile, closed difference statistics table, direction observation results table, distance observation results table, high difference observation results table, plane point error table, inter-point error table, control point results table.The process of controlling the network level difference is easy: control network data entry, coordinate calculation, coordinate estimate, selection calculation scheme, closed difference calculation and check, flat difference calculation, flat difference report generation and output.