Creation of a high-precision digital terrain model for determining the volume of extracted minerals, orthorectification of satellite images and cadastral registration of constructed objects.
The digital terrain model (DTM) is necessary for mining companies to solve several surveying tasks. Radar survey is an alternative modern method of obtaining information about the terrain. Its main advantages are a reduction in the cost of carrying out work without losing the required quality and an increase in the speed of work due to the large visibility of space survey materials. According to the requirements of maps of scale 1: 5000, the accuracy of the digital terrain model in terms of plan and height should not be less than 1 m. To achieve such high accuracy, it was necessary to accurately select the raw materials of the radar survey for their subsequent processing. The basis between the two images and the quality of the interferometric phase are crucial for the accuracy of the resulting DEM. The most suitable type of radar survey for building a DTM is data in the X-band. Therefore, based on the shooting requirements, two scenes from the Asnaro-2 spacecraft were selected. Similar characteristics of the satellite are given in this section.
Information about the work area:
The work area is in the Southern Urals. In this field, production is conducted in a closed manner, so updating information about the terrain to record subsidence is an important task.
Progress of work:
Obtaining a digital model using radar imagery is based on the application of the phase component of the signal reflected from the Earth's surface. The accuracy of the model created using this technology can vary from 10 cm to 1 m, depending on the type of underlying surface: in forested and densely urbanized areas, the accuracy decreases. Main stages of work:
Build an interferogram based on the selected scenes;
Deployment of the interferogram phase;
Use of low-frequency filters for phase smoothing;
Calculating the height component of points;
Calculation of planned corrections for terrain;
Direct construction of the DEM.
As a result of the work, a digital model of the terrain and a digital model of the terrain were built based on the materials of the radar survey. To control the results obtained, reference points provided by the customer were used. SKO turned out to be 87 cm in height and 1 m in plan. These results were satisfactory according to the requirements of the regulatory documents.