Cross sections data generation is required in many of the construction and infrastructure development activities like mining, roads, railways, airports, real estate to name a few. The data collection varies from site to site. Sometimes total stations, GPSs or similar instruments are used, and data is collected in Northing, Easting and Elevation format. In this case, it serves many purposes because contours, topography, surface-based volume calculation or other DTM based outputs can also be obtained apart from cross sections.
Auto-level is used whenever more precision is required in elevation. Data such collected will have Chainage, Offset and Elevation (COZ) format. This will help to get precise sections and quantities.
This data can be directly imported into AutoPlotter to generate longitudinal and cross sections.
Section Data Generation
Section data (COZ) from XYZ format can be converted in many ways in AutoPlotter:
Surface is created from the XYZ points imported into AutoPlotter. It is possible to obtain section data at fixed offset intervals or at variable intervals from the surface. For fixed offset interval, the elevation values are generated at regular offset intervals like -10, -8, -6, -4, -2, 0, 2, 4, 6, 8, 10. And for variable interval, the offset values can be provided by the user. Elevation value thus obtained is based on the triangular interpolation of the surface.
This type of data generation is usually useful during corridor survey. While surveying, code can be given to the points of identified offsets. For example, RR code can be specified for the right edge of an existing road at each chainage. And RL code can be given for the left edge of an existing road at each chainage. During section data generation at regular chainage intervals, data is interpolated along the selected line and not based on triangulation as explained above.
Section based on actual survey data
Sometimes total station or GPS is used as auto-level to collect the data. In such cases, it is required that the recorded elevation value should be used as it is and not the interpolated one either based on triangulation or based on linear interpolation as explained above. Using this option, it is possible to generate section data with actual RL and offset values.
All these methods of section data creation are explained in detail in the webinar that was conducted recently: