The second objective is to develop various types of sensor. Unlike previous sensors developed in several RFCS projects, though, the sensors to be developed here have features which are unique to the requirements of this project. One such requirement is for sensors, that can be fitted in key areas of a mine, that are resilient to the aftermath of major incidents, the most serious such event surely being a shock wave progressing down a gallery because of an explosion. Methods of protection will be investigated, including the fitting of the sensors into recessed, explosion-proof pods. Another aspect will be the adaptation of a small range of environmental sensors and thermal imaging cameras that can be carried onboard the drones or other autonomous vehicles, which due to the requirements of high manoeuvrability and long battery life, permit only a small payload to be carried.