Automated data acquisition system for holographic subsurface radar

Abstract

Manual data acquisition with holographic subsurface radar is quite tedious as it requires monotonous scanning with precise positioning at the beginning of each scan line and requirement to move along straight lines to obtain a microwave hologram. A good result with manual scanning requires some practice, which still leaves such difficulties as maintaining constant press to evade image interlace and rapidly degrading performance of the operator. To address these issues an electromechanical scanning system equipped with holographic subsurface radar is considered in the paper. The system allows automated acquisition of microwave holograms over an area with maximum dimension 77 by 84 cm and gives reproducible results through precise positioning. The scanning is performed with an adjustable distance to the surface without direct contact. The influence of a gap between scan plane and the sounding surface is later compensated by hologram reconstruction technique. The main mechanical and electronics components of the system are described as well as driver control strategy. A selection of acquired images is presented. The system is shown has significant increase in performance over manual scanning and recommended for automated data acquisition with other types of contact sensors.