Introduction; 3D-Radar Technology - 3d-Radar Geoscope Mk4 User Manual

TM
GeoScope User's Manual

1 Introduction

This document contains the user manual for the GeoScope™ Mk4 ground
penetrating radar system, designed and manufactured by 3d-Radar AS, see
http://www.3d-radar.com. The purpose of this document is to explain how to
assemble the hardware and use the GeoScope software. GPR and signal
processing theory is not covered by this manual. Some guidelines for
configuring the waveform will be provided.

1.1 3d-Radar Technology

The GeoScope is a three-dimensional step-frequency ground penetrating
radar. The GPR transmits electromagnetic waves through an antenna array
and measures the echo from layers and objects in the subsurface. The depth
of the objects is found by measuring the travel time from the signal is
transmitted until the echo is received. A depth estimate is obtained by
multiplying this time with the wave velocity of the signal.
TM
The GeoScope GPR is the fastest step-frequency radar on the market. By
using a digital frequency source instead of traditional phase-locked loop
TM
technology, the GeoScope can generate waveforms from 140 MHz up to 3
GHz. The step-frequency technique has a coherent receiver which means that
the whole waveform length is used as 100% efficient integration time. By
comparison, impulse GPRs use stroboscopic sampling with significant loss of
energy. Figure 1 shows an overview of the GeoScope system with optional
GPS system.
Figure 1 - GeoScope GPR system overview.
The step-frequency waveform gives optimum source signature with a uniform
frequency spectrum. The computer control allows the user to set the dwell
© 2013 3d-Radar AS Page 2 Revision 2.0 Date: 02/07/2013