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Examples of application of ground penetrating radars
1.
EXAMPLES OFAPPLICATION OF GROUND
PENETRATING RADARS
2. SEARCH FOR PIPELINES
Example of non-interpreted section.Wet clay loam section. In the center of
profile three steel pipes are buried
(140 cm in diameter, at a depth of 120 cm)
(300-MHz, 500-MHz and 900-MHz
antennas were used, wave pattern does not
change)
Fragment of GPR scanning
profile along the Moskva River. Example of
recorded diffracted wave from the pipe
placed under the river bottom. 250 MHz
antenna was used.
The pipe is at a depth of 140 cm from the
water surface.
3.
SEARCH FOR PIPELINESMeasurement of gas pipeline depth.
Antenna unit AB-250 was used.
Dielectric permittivity was determined against a hyperbola and
varies from 19 to 21.
4. VARIATION OF WAVE PATTERN DEPENDING ON DEGREE OF SOIL WETTING
Fragment of profiles scanned above a pipe 20 cm in diameter and buried ata depth of 50 cm (location of pipe is indicated by arrows).
A – profile in dry weather; B – profile in two weeks after rain.
In both cases 500-MHz antenna was used.
5. GPR PROFILE ABOVE ELECTRICAL CABLE
GPR profile recorded with antenna unitAB-250. The objective was to detect an
electrical cable under concrete
pavement. The shown profile crosses
the cable.
1 – concrete pavement, 2 - cable.
6. SEARCH FOR COLLECTORS
OBJECTIVE - MAPPING OF THE COLLECTOR AND MEASUREMENT OF DEPTH OF ITSUPPER EDGE.
250-MHz antenna unit was used.
1 – UPPER EDGE OF THE COLLECTOR; 2 – BOTTOM OF THE COLLECTOR.
DEPTH - 2 m (V=11 cm/ns), HEIGHT OF THE COLLECTOR - 1.6 m.
“SUBSIDENCE” OF WAVE PATTERNS IS OBSERVED ABOVE THE COLLECTOR,
NOISE ZONE IS BELOW THE COLLECTOR. UNCLEAR DIFFRACTION “WHISKERS”
ARE CAUSED BY RIBS OF THE COLLECTOR.
7. SEARCH FOR PIPES, COLLECTORS
Antenna unit AB-250 was used.Dielectric permittivity measured against a hyperbola is 10.25.
Mark 1 – water pipe, 2, 3 - collector
8. GPR IMAGE OF PLASTIC AND METAL PIPES LAID IN SAND
PLASTIC PIPEMETAL PIPE