This comparative study evaluates the performance of single-channel GPR (Ground Penetrating Radar) systems versus hand-pushed high-density GPR arrays for utility detection. Conducted in Gainsborough, UK, the research highlights key differences in data quality, acquisition efficiency, and processing time.
Key outcomes:
GPR arrays significantly reduce acquisition time (by two-thirds) and provide higher resolution data.
Single-channel GPRs are more cost-effective for small projects.
For mid- to large-scale commercial utility surveys, GPR arrays offer a better long-term return on investment due to improved data quality and operational efficiency.
To investigate and compare the effectiveness of two GPR solutions for utility detection:
Traditional single- and dual-channel GPR
Modern high-density GPR arrays
The goal was to evaluate performance across parameters such as:
Data resolution and density
Field acquisition time
Processing and interpretation effort
Cost-benefit implications
A side-by-side field comparison was conducted using a MALÅ Easy Locator Core and a MALÅ MIRA Compact:
Both systems were used at the same site, and data were processed using identical procedures and software (MALÅ Vision Desktop), ensuring a controlled and fair comparison.
GPR Array:
Continuous coverage in one direction
6.5 cm channel spacing
Single-channel GPR:
Bi-directional grid
0.5 m spacing between profiles
Both systems collected data at the same intersection, ensuring consistency.
Location: Gainsborough, Lincolnshire, UK
Site characteristics: Industrial area with a dense network of known underground utilities, ideal for testing visibility and performance in realistic conditions.
Pre-survey work: Included reviewing maps and utility drawings, site inspection, and GNSS positioning.
Single-channel GPR:
Bi-directional measurements
Profile distance: 0.5 m
Point interval: 0.025 m
Data size: 737 Mb
Data density (10m²): 3.2 million
Acquisition time: 6.5 hours*
Processing time: 15 min
GPR array:
Single direction measurements
Data channel dist.: 0.065 m
Point interval: 0.05 m
Data size: 1120 Mb
Data density (10m²): 12.2 million
Acquisition time: 2.5 hour*
Processing time: 15 min
*Data Collection Efficiency: Both data collections were collected with a hand-pushed cart at normal walking speed. The time of data collection for the array was 2.5 hours, and the single channel collection was 6.5 hours. The significant difference is due to the need to collect in 2 directions with the single-channel GPR and only in 1 direction for the array.
While both technologies are viable, the GPR array offers clear advantages in data quality, processing speed, and usability. For commercial applications, especially larger sites, the array system is the more efficient and cost-effective solution over time.
We would like to thank the guys at Sygma that conducted the data collection.