LineTrac XT accessory for StructureScan Mini XTPublished 16/5, 2017 at 15:47
The American company Geophysical Survey Systems in New Hampshire has added the LineTrac XT accessory for StructureScan Mini XT to detect AC power and RF energy in conduits. GSSI is also launching the HyperStacking ground penetrating radar technology that allows users to see deeper targets and operate in noisy conditions. Mikael Karlsson reports.
The StructureScan Mini XT offers a 2.7GHz antenna for superior target resolution.It can reach depths of 500mm and is ideal for locating rebar, conduits, post-tension cables, voids, and real time determination of concrete slab thickness.
The combination of the StructureScan Mini XT and LineTrac XT helps concrete contractors to locate power sources in concrete, including AC power and induced RF energy present in conduits. The new LineTrac XT accessory combines radar data with a magnetometer, delivering accurate and repeatable performance.
LineTrac XT includes a number of features that make it easy to identify target utilities. This includes easy integration with StructureScan Mini XT, seamless data fusion with GPR data, a 50/60Hz electro-magnetic sensor used to locate powered conduits, and a IP-65 rated enclosure. LineTrac XT detects extremely low amplitude AC signals associated with difficult to locate conduits.
The LineTrac XT accessory complies with all applicable FCC, RSS, RoHS, and CE requirements. It can operate in temperatures ranging from 20°C to 40°C.
The StructureScan Mini XT now comes equipped with the LineTrac XT software package. Users simply insert the LineTrac XT into the front accessory port, select the LineTrac XT module, and choose between 50 Hz and 60 Hz.
GSSI’s new HyperStacking GPR technology is patented by GSSI, and greatly improves the receiving performance of a GPR system while maintaining measurement speed and radiated emission limits. It uses high speed interpolated sampling to reduce such commonly encountered issues as dynamic range limitations, regulatory compliance issues, sampler core offset error, and timing errors.
The benefits of the new HyperStacking technology are pronounced in lower frequency applications, such as in dirt, clay, sand, and more. In these conditions, the ground media is sufficiently loose to make the benefits of HyperStacking clear. GSSI is developing its HyperStacking technology in a range of antenna frequencies to meet the specific needs of a variety of applications.
The 350MHz antenna, for instance, is ideal for utility detection in soil conditions in the 0-4.5m range. Lower-frequency antennas, in to 100-200MHz range, are uited for geotechnical applications, such as water table analysis, characterization of shallow stratigraphy, bedrock depth analysis, and analysis of deep geological structures. In these applications, traditional techniques such as ETS cannot achieve the same level of precision as HyperStacking.
With the commonly used ETS technique, hundreds or even thousands of pulses are transmitted to obtain a full measurement set over the desired time range. However, most of the received energy is discarded and the resultant measurement is inefficient, in terms of noise, relative to the amount of energy transmitted.
By contrast, the new technology uses high speed interpolated sampling, which recovers all or most of the reflected radar information, greatly improving the measurement signal energy with respect to noise.
In the past, these techniques have been expensive and far too energy consuming, but recent advances in integrated circuit technology have enabled the development of low-cost devices that perform at reasonably high speeds while consuming relatively small amounts of power.
This more efficient signal detection directly translates to improved system performance in certain applications. Measurement results produced by the technique resolve targets at least 5% deeper and 5% smaller than conventional ETS GPR.
The system can also produce individual measurement results at extremely high speeds, at least 1000 times that of a conventional ETS system.