The compatibility of Kurs One relative positioning hardware solutions verified.

The work was aimed at assessing the possibility of using available computer modeling systems provided by general-purpose radio engineering systems and electromagnetic field computer modeling systems to verify the compatibility of hardware solutions, offered for search-and-tracking radar prototype manufacturing, with technical specifications for a spacecraft rendezvous system in terms of the accurate relative positioning of objects and the specified approach trajectory establishment.

The computer modeling was conducted in the CST Microwave Studio full-wave EM simulation program. An object that fully reproduces a 3D geometry of the mechanical model was utilized as a target. The surface material was an ideal conductor. The scene geometry is shown in Figure 1. The simplest antenna system configuration was chosen.
The simulation system included an isotropic radiator as a transmitting antenna and two isotropic pick-up probes located at a 20-millimeter distance from the radiator. The distance between the pick-up probes was 1.9 mm. All radiators were located in the XZ plane. The target angular coordinate variation occurs in the same plane. To simulate the scene, an Asymptotic Solver based on the Shooting and Bouncing Ray method was chosen.

Each experiment resulted in the phase difference of the EM field scattered by the target between the Rx1 and Rx2 probes’ location points.

Figure 1. Computer modeling scene geometry (not to scale).

It should be noted that the selected simulation technique is based on the method that uses calculations in the frequency domain, and that imposes restrictions on the excitation signal type. Namely: exclusively a fixed frequency continuous sinusoidal signal is acceptable.
The experiment objective was to determine the possibility of using the electromagnetic field numerical simulation programs available to the operator to verify the performance of the upcoming radar development as part of the scenario specified by the draft technical requirements.

To complete the project, the following works were executed:
  1. The nature of the problems was determined when the radar carried out the tasks as part of the scenario specified by the draft technical requirements.
  2. A list of electromagnetic field numerical simulation programs’ perspectives with a view to their application in a radar development process was specified.
  3. The numerical experiments were conducted in the CST Microwave Studio environment, using the SBR (Shooting and Bouncing Ray) technique to execute electromagnetic simulation for the basic configuration of a device designed to sense radiation source direction based on a phase interferometer.

The results obtained were as follows:
  1. The method chosen to solve the problem of electromagnetic waves scattering when used to simulate an ideal radar utilization scenario returns the results being in line with the results obtained analytically.
  2. The data returned by the simulation using real target geometry matches qualitatively and in order of magnitude with the expected outcome and proves the nature of the problems with using radar to locate complex distributed targets.

  1. The outcome of the numerical experiments allows making a conclusion about the chosen method applicability for testing and verifying radar unit designs and a whole radar structure being under development.
  2. The numerical experiment was conducted to demonstrate the applicability of frequency diversity principles, as well as statistical approaches to the problem of complex distributed target radar localization.