A method for monitoring surface deformations of a scenario by means of differential interferometry technique, said method comprising the steps of: - prearranging a radar sensor comprising at least one transmitting antenna and a receiving antenna arranged to transmission and acquisition of radar signals, said radar sensor arranged to move along a planar trajectory γ having centre 0; - defining a reference system S having origin in said centre O; - acquiring by SAR technique said scenario by means of handling said radar sensor along said planar trajectory γ, said radar sensor being configured in such a way that the radiation pattern of said antennas (111,112) is oriented radially with respect to said centre O, said acquisition occurring at points of acquisition s i arranged on said trajectory γ, obtaining a plurality of data for each point of acquisition s i, said acquisition being carried out at least at a first height of acquisition h a 1 and at a second height of acquisition h a 2 ≠ h a 1; - defining a plurality of target points t i of said scenario, the three-dimensional position of each target point t i being defined by means of spherical coordinates ( ρ i, θ i, β i) referring to said reference system S, being known the values of said coordinates ρ i and θ i; said method further comprising a step of three-dimensional determining of said target points t i by the steps of: - focusing at said first height of acquisition h a 1 each target point t i with respect to its own position considering a value of β i predetermined and equal to β 0; - focusing at said second height of acquisition h a 2 ≠ h a 1 each target point t i with respect to its own position considering a value of β i predetermined and equal to β 0; - controlling, by means of interferometric technique, said focusings at the height of acquisition h a 1 and h a 2 obtaining a value of said coordinate β i for each target point; characterised in that a step is further provided of global focusing each target point t i with respect to its own three-dimensional position defined by said spherical coordinates ( ρ i, θ i, β i), obtaining a first focused radar datum, said step of focusing being obtained, for each target point t i, by analyzing data obtained at each point of acquisition s i wherein said target point t i is detectable. - prearranging a radar sensor comprising at least one transmitting antenna and a receiving antenna arranged to transmission and acquisition of radar signals, said radar sensor arranged to move along a planar trajectory γ having centre 0; - defining a reference system S having origin in said centre O; - acquiring by SAR technique said scenario by means of handling said radar sensor along said planar trajectory γ, said radar sensor being configured in such a way that the radiation pattern of said antennas (111,112) is oriented radially with respect to said centre O, said acquisition occurring at points of acquisition s i arranged on said trajectory γ, obtaining a plurality of data for each point of acquisition s i, said acquisition being carried out at least at a first height of acquisition h a 1 and at a second height of acquisition h a 2 ≠ h a 1; - defining a plurality of target points t i of said scenario, the three-dimensional position of each target point t i being defined by means of spherical coordinates ( ρ i, θ i, β i) referring to said reference system S, being known the values of said coordinates ρ i and θ i; a step of three-dimensional determining of said target points t i by the steps of: - focusing at said first height of acquisition h a 1 each target point t i with respect to its own position considering a value of β i predetermined and equal to β 0; - focusing at said second height of acquisition h a 2 ≠ h a 1 each target point t i with respect to its own position considering a value of β i predetermined and equal to β 0; - controlling, by means of interferometric technique, said focusings at the height of acquisition h a 1 and h a 2 obtaining a value of said coordinate β i for each target point; - focusing at said first height of acquisition h a 1 each target point t i with respect to its own position considering a value of β i predetermined and equal to β 0; - focusing at said second height of acquisition h a 2 ≠ h a 1 each target point t i with respect to its own position considering a value of β i predetermined and equal to β 0; - controlling, by means of interferometric technique, said focusings at the height of acquisition h a 1 and h a 2 obtaining a value of said coordinate β i for each target point; characterised in that a step is further provided of global focusing each target point t i with respect to its own three-dimensional position defined by said spherical coordinates ( ρ i, θ i, β i), obtaining a first focused radar datum, said step of focusing being obtained, for each target point t i, by analyzing data obtained at each point of acquisition s i wherein said target point t i is detectable.