One of the important tasks facing the regional authorities is to monitor the condition of roads and power lines. In the Ulyanovsk region more than 8 thousand km of power lines and more than 9 thousand km of roads (including rural). A significant part of these facilities is located outside the settlements in places with medium and low availability. In many such places there is a problem of uncontrolled forest overgrowth. This work is devoted to solving the problem of automated satellite monitoring of such areas. For this purpose, it is proposed to use a modified convolutional neural network that processes time sequences of multispectral satellite images and allows to allocate territories occupied by forest and undergrowth with high accuracy. This approach allows us to assess the dynamics of overgrowth of the territory and perform the appropriate forecast with sufficient accuracy for practice.
IntroductionOne of the important tasks of the satellite image processing is its thematic mapping, i.e. division of image into identifiable areas containing the similar visual, correlation or texture characteristics of pixels. The use of standard segmentation algorithms [1-3] for thematic mapping of satellite images usually leads to significant errors caused by two reasons. Firstly, these algorithms are largely incapable of taking into account the multi-zonal nature of remote sensing (RS), so each satellite image contains the results of the Earth's surface registration in different spectral ranges. Some works [4][5][6] suggest the possibility of processing hyperspectral images. Thus, the authors based their theory on criterion of uniformity for reception of connected areas of such hyperspectral image [4], modification and generalization of algorithm K-means [5] and use of physical properties of a satellite data [6]. Secondly, the existing approaches unable to use data on the observed territory received at previous points of time for image segmentation. But using such data can significantly improve the quality of processing at the expense of a fundamentally larger amount of information, but it is fraught with difficulties of aggregation.It is possible to overcome the mentioned disadvantages by using neural network procedures of segmentation and classification of multidimensional data. In work [9] the variant of the U-NET neural network with full-connected layers (FCN) modification is presented. Herewith the input layer of the network consisting from spectral layers of the multizonal image has been extended by three auxiliary 2d halftone images obtained from the original using NDVI, EVI, SAVI transformations and two 2d arrays , representing the segmentation results at the previous point of time and one year ago. The use of two such reference markings allows one's to reduce the error of classification in case of rapid changes of the terrain due to the change of year time and in case of marking array absence at the