Aerospace Instrument-Making Annotation << Back ON THE POSSIBILITIES OF USING THERMAL IMAGERS TO DETECT OBSTACLES THAT IMPEDE FLYING HELICOPTERS V.A. Ovsyannikov, Y.V. Ovsyannikov, V.L. Filippov This paper offers a detection probability calculation model of the main obstacles that impede the taking off and landing of helicopters, specifically electricity power lines, in adverse weather conditions (at nighttime and/or in fog or snowfall) by means of modern, high-sensitivity thermal imaging devices, notably staring devices. An engineering method of predicting the thermal contrast of these lines sighted against the earth surface or the sky has been developed; numerical estimates of this contrast under various elevation angles of the power lines and the corresponding probability of their detection have been made. This method takes into account the temperature contrast of the lines and the surrounding air caused by electric current in the lines, temperature stratification of the atmosphere, and the thermal radiation of the surrounding area and the sun, as well as the difference in emissivity of the earth background and the surface of the lines in various spectral working band of the devices. Concrete calculation results are provided as well. Keywords: thermal imagers, power lines, thermal contrast, object detection. DOI: 10.25791/aviakosmos.07.2020.1166 Pp. 12-23.