This invention addresses remote inspection of target in monitored space. A three dimensional (3D) microwave image of the space is obtained using at least two emitters. The data undergoes coherent processing to obtain maximum intensity of the objects in the area. This image is combined with a 3D video image obtained using two or more video cameras synchronized with the microwave emitters. The images are converted into digital format and transferred into one coordinate system. The distance l is determined between the microwave and the video image. If l lo then the presence of cavities is analyzed. If the cavity depth h is greater than the threshold value ho a concealed dielectric object at the target is ascertained: h 0 = l 0 ⁢ ɛ - 1 √ ɛ where ∈ is dielectric permeability of the sought dielectric object.