| 摘要 |
<p>A method of locating an object in an optically dense atmosphere (15) includes transmitting a pulsed wave optical signal (16) towards the object through the atmosphere adjacent the object. A particular application is the location of the surface (14) of the contents of furnace (10), for example the burden (12) in a blast furnace. A received signal including at least a portion of the signal reflected by the object is monitored and analyzed in relation to the transmitted signal to determine the location of the object. This analysis comprises identifying the trailing edge of the received pulse signal to ascertain the time elapsed between the detection of the transmitted and received signals.</p> |
