Abstract: A system for the detection and measurement of atmospheric air movement irregularities such as wind velocity vector, wind shear, downdraft, clear air turbulence, aircraft induced vorteces and turbulence, in particular along a glidepath near airports, whereby an air volume under investigation is illuminated by a radio wave transmitter with a beam of coherent electromagnetic energy and a resulting wave field is received and processed in processor means to derive information on the existence of said atmospheric irregularities and furthermore to give specific measurements of related parameters, comprising at least one receiver for said resulting wave field, which is due to scattering in said air volume, positioned at a bistatic location having a selected distance from said transmitter, characterized by acoustic transmitter means located between said transmitter and said at least one receiver, and adapted to emit acoustic waves into said air volume, with frequency and beamwidth of the acoustic waves chosen such tha

Abstract: System for seismic profiling of structures (2) beneath the sea bottom, comprising an acoustic transducer array (12) which synchronously and coherently generates an acoustic wave adapted to be reflected from said structures (2). When the reflected acoustic waves propagate towards the water surface (1), there is caused a perturbation of the electromagnetic reflection coefficient thereof. Receiver means for detection and characterization of the received acoustic field at the surface (1), comprises a radar system (10) illuminating the region concerned of the surface (1) and imposes thereat a number of interferograms each corresponding to the acoustic field from a scattering point given by the position thereof and the frequency of the field. By recording the degree of coincidence between the interferograms and the acoustic perturbation pattern on the water surface (1), the seismic properties of said structures (2) are surveyed.