# Fiber-Optic System for Monitoring Pit Collapse Prevention
## 2 Materials and Methods
### Hardware and Software
Moreover, the physical number of channels is limited to four due to the limited computing capacity of the computer and the performance of the video card, as well as the created program algorithms, but in the future, their number will be increased to the real needs of the enterprise. Increasing the number of channels will definitely increase the cost, primarily due to increasing the length of the fiber-optic control cables, but safety issues are a higher priority. The software for the open pit monitoring system for mining monitors the displacement of the pit walls is based on changing the number of pixels. The useful signal is separated from interference and noise generated by various impacts based on the developed algorithm, for example, temperature changes, as well as mechanical vibrations caused by the operation of equipment or people; moreover, when using the machine learning technology based on new data obtained during operation, the system learns, reducing the error of determination. The hardware-software complex is able to track the rate of change in the derivative of the light wave intensity in time, as well as changes in the shape of the spot and the transition of pixels from white to black. The system can also stepwise change its sensitivity. Initially, it is set to the maximum sensitivity to control the initial displacements and to give warning signals to the operator, after which the parameters are automatically coarsened for accurate fixing the displacement and eliminating false measurements. The system is able to control changing rock pressure and displacements of roof rocks by changing the level of additional losses and changing the intensity of the light wave incident on the surface of the photodetector. Intelligent processing of the spot image makes it possible to track changes in the intensity of individual pixels. Figure 7 shows a window with images of light spots in a calm and disturbed state under mechanical action on the FOS. On the computer screen, it can be clearly seen how the light spot changes, especially at the interface between the core and the cladding of the OF. The light falling on the surface of the television matrix contains a significant amount of noise. At the output of the OF, a light spot is formed, which falls on the surface of the television matrix and obeys the normal Gaussian distribution. The noise negatively affects the measurement process, but the program monitors the dynamics of changes in the shape of the light spot and is able to separate fluctuations caused by external factors, such as thermal effects on the OF, from useful signals. The operation of the system is partially based on the effect of photoelasticity and changing additional losses during mechanical action on the OF. The program has several windows for configuration and operation. During operation, the screen displays not only the numerical values of the load, by which the displacement is calculated, but there are also the signal indicators of green, yellow and red colors, which are needed to warn of danger or vice versa about the normal operation of the system. With a sharp fluctuation in pressure and increasing the displacement parameter, a warning signal is given, and a yellow indicator turns on, indicating that the roof rocks have begun to move due to increasing rock pressure.