AbslraeL @er the years, lidar probing has k e n widely used to identify doud properties (e.g. thickness and ancentration) in an atmosphere. In the current paper, we mamine the inverse problem of reconstructing the doud mncentralion from lidar signal. The problem that is considered is a hyperbolic system of fint-order partial differential equations in a semi-infinite medium. The issues of existence, uniqueness and mnlinuous dependence on initial data of the inverse problem are addressed.