The steadily increasing demand for natural gas necessitates the development of safe, well-controlled and reliable gas networks at minimal cost. A similar situation exists in the telecommunications industry where there is a voracious demand for increased capacity and new installations.

For the installation of all new underground infrastructure, Trenchless Technologies such as HDD or pipe bursting can play a key role, particularly when it is important to reduce disturbance to traffic and people living nearby.

However, using such techniques without reliable information on existing utilities and the local geology can be problematic and even dangerous.

For this reason, Ground Probing Radar (GPR) is a very attractive technique because, of all the state-of-the-art underground investigation methods available, it is the only one capable of accurately locating both metallic and non-metallic buried objects without prior knowledge of their position.

However, the detection of utility networks imposes a particular set of constraints on the design of an effective GPR system. Most buried pipework is between 1.5 to 2 metres below ground, but it may vary widely in size, material type, position, and it may be buried in any of a wide range of soil types - resulting in large differences in both the absorption and the velocity of electromagnetic waves. As a matter of fact, mistakes due to the use of inadequate or general purpose GPRs have often produced bad results and disappointed professionals.

It was in the early 90s that IDS focused on the development of specialised systems to be used for different applications, replacing the more traditional general purpose radar systems in order to overcome their main limitations.

For instance, some of the specific requirements when using GPR technology for locating utilities are penetration depth, resolution (both vertical and horizontal) and detection of small plastic pipes, which form an important class of objects that end users wish to locate. These requirements lead to conflicting technical solutions: while high frequencies are needed to provide resolution, they are quickly absorbed by the ground and provide limited penetration depth. Low frequencies provide greater penetration depths, but cannot detect small non-metallic targets.

To satisfy these requirements, IDS products for locating and mapping utilities use wide-band, multi-frequency antennas, unique on the GPR market, providing the high frequencies to enable the desired resolution (albeit with a limited penetration depth), while the lower frequencies permit penetration to a depth of as much as 3 m in many soil types (with limited resolution).

A further, common problem related to this technique is that the quality of the information extracted from the raw radar data strongly depends on the training and skill of the operator. On the contrary, IDS software for GPR data analysis has been designed to allow even an inexperienced user to easily and confidently interpret radargrams and extract the most useful information.

With and IDS GPR, the depth and position of identified underground utilities are automatically transferred to a 3D CAD drawing, the final output of the system, useful for choosing the best and safest drilling path.

The RIS MF is a multi-channel, multi-polarisation and multi-frequency system that provides a completed 3D underground map with the highest level of reliability.

It uses an array of multi-frequency antennas operating simultaneously to collect data that can be easily combined and reliably cross referenced to increase target detection probability. It also allows fast surveying of large areas, featuring unmatched performance in terms of accuracy. Moreover, the RIS MF can provide information on soil type in the final CAD map, enabling the selection of the most suitable digging equipment.

The RIS MF is currently being used to create a 3D map of the entire light rail and metro networks in Dublin, Ireland. The system has allowed the work to be optimised and has represented a fundamental instrument for controlling and reducing risks for the companies contracted to perform remodelling and construction work.

The Detector Duo will be presented for the first time at International No Dig 2006 and has been designed for use just before or during excavation, in order to avoid damage during installation.

By running a multi-frequency antenna, the equipment can collect two GPR profiles during a single scan; data is processed and displayed in real time to let the operator easily identify and mark on the ground the position of both shallow and deep buried utilities.

The complete suite of GPR products guarantees the maximum quality and maximum safety both for users and the public, while maintaining a good cost balance. Furthermore, IDS is devoted to providing complete after sales customer care, guaranteeing total technical assistance both for the GPR tools and data analysis.

During the International No Dig 2006 in Brisbane, IDS GPR products for locating and mapping utilities will be presented and demonstrated by JB Sales International at Booth 4.