A method is proposed for obtaining 3D radio images by measuring the amplitude of interference of the fields of the reference and object waves by a movable transmitter-receiver module with scanning in a broad frequency band. The results of numerical simulation and experiments with the proposed system of radio vision in the frequency range from 1 to 13 GHz are considered.

An apparatus for obtaining two-dimensional images of sheet-metal products that is based on a scanning matrix of spiral induction coils has been designed. It was experimentally shown that it is possible to detect flaws and objects that are hidden behind metallic barriers. The scanning area was 37 × 32 cm and the measurement step was 5 mm. Special treatment allows one to restore the distribution of induction currents in conductive objects from the remote measurement of the normal-component distribution of the magnetic induction vector on a plane.

A method of control for an ordered group of particles that levitate in an ultrasonic field and structures of rectilinear segments is proposed. An ultrasonic field in air at a frequency of 40 kHz and particles whose dimensions are less than a quarter of a wavelength or thin cylindrical objects with diameters of less than a quarter of a wavelength are considered. The ultrasonic field is formed using four phased arrays of radiators that are placed oppositely on lateral faces of a rectangular parallelepiped. The radiators form a distribution of the standing wave field in the plane, which provides levitation of particles in a rectangular grid in a plane layer. With the use of numerical simulation and experimentally, it has been shown that the obtained distribution is stabilized and the particles remain immobile at local minimums of the Gor’kov potential. Moreover, regulation of the phase difference of opposite radiators provides controlled motion of a group of particles in a horizontal plane and a change in the focusing plane of side radiators provides controlled motion of a group of particles along the vertical plane. It has been shown experimentally that not only small particles but also structures assembled of rectilinear segments whose length is much greater than the wavelength can levitate in this field distribution.

We propose a method for spatial resolution enhancement of eddy current images obtained by magnetic induction 2D scanning. A measurement technique based on a scanning differential source of an alternating magnetic field combined with a receiver is considered. A flat spiral coil is used as a receiver. The dimensions of the receiver and source coils are larger than or comparable with the dimensions of the objects under study. We represent an electrically conductive object as a set of small diameter conductive coils with a specific current induced by an external source. The method proposed solves the forward and inverse problems for linear coefficients describing the distribution of small coils representing a flat conductive object of arbitrary shape. This method was verified numerically and experimentally. The visualization of the object at a range of 15 mm with appropriate spatial resolution is shown experimentally at a frequency of 30 kHz. This method could be applied for the non-destructive testing and visualization of metallic objects. The novelty of the proposed method lies in the fact that it provides the ability to use probe coils with sizes much larger than inhomogeneities. We also proposed a method for calculating the hardware function of the system and solving the inverse problem. Detailed object visualization with sizes smaller than the probe system of the coils is provided. The possibility of increasing the resolution by seven times at a noise level of 0.1% is shown numerically.