<p>Like…what ranging sensor would be suitable to give some sort of an idea about the design of the rooms/walls/corridors if the room was on fire?</p>
<p>sonic sensors seemed suitable to be at first, but then wouldn’t the speed of sound vary depending on temperature?</p>
<p>And won’t visible/infrared light based ranging sensor be impossible to use if the room was on fire?</p>
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That is certainly a concern, the question should be whether or not the inaccuracy in the results due to change in speed of sound and heat turbulence is more than you can allow. No system will be perfect, you would need to decide how much error is acceptable.</p>
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Visible and near-IR will likely be obscured by smoke and thereby useless. Mid-IR will be spoofed by the fire itself. Long-IR (>20um) might work. Might.</p>
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You need to do a trade study on the types of sensors available against the penetrability of the smoke, the ambient, heat, and other issues. Lidar would be the best choice for a clear room, a low-powered S-band (or shorter) radar might be a good choice here.</p>