GPR GPR Signal Processing & Analysis 2

Question 1

When converting GPR two-way travel time (TWTT) to depth, which parameter is essential?

Accepted Answer

Electromagnetic wave velocity in the medium

Answer

Depth is calculated as half the TWTT multiplied by the EM velocity, so an accurate velocity for the specific material is required.

Question 2

What is a common indication of a metallic pipe in a GPR radargram?

Accepted Answer

A strong hyperbolic reflection with ringing below

Answer

Metallic pipes produce a strong hyperbolic diffraction pattern due to their point-source geometry and generate multiple internal reverberations (ringing) from the high dielectric contrast.

Question 3

Which software feature allows a GPR operator to overlay processed scan data on a site plan for reporting?

Accepted Answer

Data merging/georeferencing

Answer

Georeferencing and data merging tools allow GPR results to be spatially registered to site drawings or GPS coordinates for accurate reporting.

Question 4

The Hilbert transform in GPR data processing is used to produce:

Accepted Answer

A phase-shifted version of the signal to compute instantaneous amplitude (envelope)

Answer

The Hilbert transform computes the analytic signal, whose magnitude gives the instantaneous amplitude (envelope), useful for highlighting strong reflectors.

Question 5

What does a 'flat reflector' with no hyperbolic tails typically represent in a GPR scan?

Accepted Answer

A planar interface such as a layer boundary or void ceiling

Answer

Flat continuous reflectors indicate planar interfaces (e.g., layer boundaries, voids, or slabs) where the reflection geometry produces a horizontal event rather than a diffraction.

GPR - Ground Penetrating Radar Specialist Certification Practice Test

GPR - Ground Penetrating Radar Specialist Certification Practice Test

GPR GPR Signal Processing & Analysis 2