A method of kinematic ranging comprising the steps of: (i) measuring the bearing α 1 in azimuth of a jammer at a time t 1 with respect to a first position using an airborne radar detector located at the first position; (ii) measuring the rate of change dα/dt of the bearing in azimuth of the jammer with respect to the first position using the airborne radar detector located at the first position; (iii) causing the airborne radar detector to carry out a manoeuvre such that it is displaced to a second position by a horizontal displacement d having orthogonal components Δx, Δy in a time Δt = t 2 - t 1 and measuring the bearing α 2 in azimuth of the jammer at time t 2 with respect to the second position using the airborne radar detector located at the second position, where d = Δ x 2 + Δ y 2; (iv) calculating the difference Δα in the bearing in azimuth of the jammer between the second and first positions; characterised in that the components Δx, Δy are calculated by the steps of: (a) choosing a desired relative range accuracy σ R /R for the method; (b) obtaining an estimated range R est of the jammer from the second position at time t 2; (c) finding d, under the assumption that Δβ = π/2, Δβ being the angle between the straight line joining the position of the airborne detector radar at time t 1 and the position of the jammer at t 2 and the straight line corresponding to the displacement of the airborne detector radar during the interval Δt, on the basis of the relative range accuracy, the estimated range R est, the variance σ Δα 2 in Δα and the variance σ d 2 in d σ R = R d R 2 − d 2 ⋅ σ Δ α 2 + σ d 2 (d) calculating the components Δx, Δy of the displacement d according to Δ x = cos α 1 + α ̇ ⋅ Δ t ⋅ d Δ y = − sin α 1 + α ̇ ⋅ Δ t ⋅ d and characterised in that the range R of the jammer from the second position is calculated according to R = d sin Δ α. (i) measuring the bearing α 1 in azimuth of a jammer at a time t 1 with respect to a first position using an airborne radar detector located at the first position; (ii) measuring the rate of change dα/dt of the bearing in azimuth of the jammer with respect to the first position using the airborne radar detector located at the first position; (iii) causing the airborne radar detector to carry out a manoeuvre such that it is displaced to a second position by a horizontal displacement d having orthogonal components Δx, Δy in a time Δt = t 2 - t 1 and measuring the bearing α 2 in azimuth of the jammer at time t 2 with respect to the second position using the airborne radar detector located at the second position, where d = Δ x 2 + Δ y 2; (iv) calculating the difference Δα in the bearing in azimuth of the jammer between the second and first positions; (a) choosing a desired relative range accuracy σ R /R for the method; (b) obtaining an estimated range R est of the jammer from the second position at time t 2; (c) finding d, under the assumption that Δβ = π/2, Δβ being the angle between the straight line joining the position of the airborne detector radar at time t 1 and the position of the jammer at t 2 and the straight line corresponding to the displacement of the airborne detector radar during the interval Δt, on the basis of the relative range accuracy, the estimated range R est, the variance σ Δα 2 in Δα and the variance σ d 2 in d σ R = R d R 2 − d 2 ⋅ σ Δ α 2 + σ d 2 (d) calculating the components Δx, Δy of the displacement d according to Δ x = cos α 1 + α ̇ ⋅ Δ t ⋅ d Δ y = − sin α 1 + α ̇ ⋅ Δ t ⋅ d and characterised in that the range R of the jammer from the second position is calculated according to R = d sin Δ α.