A TECHNIQUE OF AUTOMATIC LOCALIZATION OF SURVEILLANCE OBJECTS ON THE ROUTE OF SPACE SCANNER SURVEY AND THE ALGORITHM OF CONSTRUCTING PROTOTYPE SCANNER IMAGES

Abstract

The article considers the tasks related to the prevention of emergency situations and the assessment and prediction of the consequences of natural disasters. It is shown that the effectiveness of these problems solution depends to a high degree on the efficiency of the analysis of the existing situation and the current state of the objects of surveillance in hazardous areas. At the same time, the most important source of information for decision-making are space images, primarily digital images, since they can be transmitted over high-speed radio-frequency transmission lines from the spacecraft to ground space information receiving points immediately after the survey. Scanner images obtained by optoelectronic scanning systems are among them and of special importance, since optoelectronic scanning systems ensure the registration of vast territories with high detail. During the ground images processing, two main tasks are solved, namely, the localization of surveillance objects in satellite imagery, connected with obtaining preliminary assessments and issuing target designations to ground forces and facilities for performing immediate operations aimed at eliminating existing threats, and detailed analysis of the situation and the current state of the surveillance objects with the clarification of previously issued target designations. In this case, the highest requirements for operational response are imposed on the solution of the first task. They are caused by the need to find the location of surveillance objects on the space imagery being processed as soon as possible. The known techniques of the localization of surveillance objects on space scanner images, namely, visual, photogrammetric (direct and iterative), correlation and approximation ones are considered. It is shown that on the one hand, in conditions of a huge amount of incoming for processing specific space information, and limited hardware and software resources of ground stations for processing space information, on the other hand, photogrammetric techniques for localizing surveillance objects on the survey route are the most acceptable ones. The known photogrammetric techniques are applied in the interactive mode and do not require large computational resources, since they are based on simple algebraic calculations in each iteration for a single point of an image. At the same time, the scope of the technique is critical to the duration of the survey route being processed, since along with the technological operations performed in the automatic mode (selection of image fragments) it contains the operations of the operator performing a visual assessment of the presence of surveillance objects in images. To eliminate the identified shortcomings, a technique for automatic localization of surveillance objects in space scanner images of vast territories by organizing their photogrammetric processing was proposed and considered. To test the efficiency of the technique and to study its effectiveness, an algorithm for constructing prototype scanner images on the surface of a common terrestrial ellipsoid has been developed.