LandScope has developed a full utility and service mapping service of which various levels, including TSA Level 6, may be selected by the customer depending on specific survey requirements.
For projects of this nature we integrate the ground penetrating radar (GPR) approach with more traditional radio-location technology to ensure maximum data recovery and minimum data ‘holes’, i.e. missed targets. Additionally all adjacent manholes, inspection chambers and other associated infrastructure is lifted and documented. The critical success factor of an underground utility mapping project inevitably boils down to diligence.
A typical survey would comprise:
- Prior to commencement of the underground survey a detailed desk-top study is conducted whereby all available service data would be compiled and reviewed. This process provides the opportunity to better plan the underground survey, reduce the risk of underground feature mis-identification and allows a ‘check-list’ approach to utility / service tracing.
- Lift and document, in detail, all Inspection Chambers / Man-holes in conjunction with data received from the desk study. This would extend beyond the immediate survey site so as to allow the subsequent tracing of services through the area of interest – i.e. working from whole to part
- Utilising the Radiodetection RD8000, trace and mark all conducting (i.e. metallic content) service lines
- Passive modes – radio and electric
- Active mode – multiple frequencies as appropriate
- Current direction – discern between electrically bonded services
- Radiodetection RD8000 would be used in conjunction with a radio-sonde device so that accessible major open lines (i.e. foul and storm drainage lines and non-traceable ducting systems) can be located
- Utilising GSSI Sir3000 UtilityScan Ground Penetrating Radar (GPR) perform tightly lined spcaed grids across the area in order to verify positions of non-conducting services such as water and gas PE lines. Clearly the application of the GPR will also verify the locations of lines detected with the RD8000. The ground penetrating radar system may be configured with 270MHz, 400MHZ or 900MHz antennae to be selected as required
- All GPR data is recorded for subsequent post-processing, modelling and analysis. This approach is considered an absolutely essential element to obtain maximum value from the GPR data-set and mitigate the risk of poor GPR interpretation. Post processing includes:
- Noise removal
- Time Gain Adjustment
- Dielectric Constant Adjustment
- Coordinate underground survey works to survey reference framework. LandScope has developed sophisticated feature code libraries which enable all service attributes measured and observed in the field to be recorded as part of this process
- All GPR data shall be post-processed and reviewed at the nearest LandScope facility
- GPR derived data is overlaid to that derived from radio-location survey and other
- The survey would be presented in digital AutoCAD (DWG) and Adobe PDF formats as specified with underground services included as seperate drawing layers. Project specific templates would be created to facilitate and expedite deliverable product
- All drawings are checked by survey operatives and independently checked by the survey manager
- LandScope Engineering operates a rigorous system of drawing management which includes a detailed register of drawing revisions, issues etc.
Survey results can be delivered in a variety of formats from surface marking to 3D AutoCAD geo-referenced drawing files.