MEASURED BUILDING SURVEYS
Sigma Surveys can carry out any aspect of your required measured building survey, whether it be floor plans, internal / external elevations, reflective ceiling plans, roof plans, cross sections or all of the above. We use a combination of Trimble TX8 / Leica RTC360 laser scanners and MBS building surveying software to accurately plot all walls / windows / doors / fixed furniture / sanitary etc. On completion of our site survey, the data is imported to AutoCAD and processed into a digital drawing that can be utilised by our clients for future designs.
3D SCANNING / BIM MODELS
We can provide 3D Pointclouds / 3D Revit models of any type of structure, building or area of land. Whether undertaken using terrestrial laser scanning methods or UAV / Drone technology, our data is registered within software such as Leica Cyclone or Trimble RealWorks to ensure accuracy between individual scan locations. The data can be exported to various file formats for upload to ArchiCAD, Revit, Recap and other types of 3D drafting software.
A RealWorks viewer can be downloaded from the following link to import the registered pointcloud if required. https://geospatial.trimble.com/products-and-solutions/trimble-realworks
Pointclouds and models can be produced from our Drone / UAV by utilising Ground Control Points (GCPs) to provide accuracy as well as georeference to OS grid and datum. The images are stitched together in Pix4D where Pointclouds and rendered models can be generated with great accuracy.
INTERNAL / EXTERNAL AREA PLANS & LEASE PLANS
We can provide Net / Gross Internal Area plans (NIA / GIA) of buildings to RICS Code of Measuring Practice and IPMS, whether shell and core or heavily fitted out. Our approach is to treat the survey as we would a measured building survey to ensure absolute accuracy. The surveys are undertaken using a combination of Leica RTC360 laser scanner and MBS building survey software to measure around all structural walls / columns etc. Our plans are completed with areas calculated using polylines and hatching within AutoCAD. Completed drawings are issued as an AutoCAD compatible file as well as a PDF with areas hatched in varying colours for designation of use. Lease plans / zoning / dimensions / net & gross frontages are included on our drawings where applicable.
LAND, HYDROGRAPHIC & ENGINEERING SURVEYS
Our topographical surveys are generally undertaken using a combination of Trimble S6 / S7 total stations and Trimble R10 GNSS receivers. Our total stations are fully robotic, therefore our surveyors are in complete control of the field survey / data coding etc.. Our GNSS receivers capture data from GPS / GLONASS / Galileo / Beidou satellites to provide the best accuracy possible. Together with a Trimble VRS Now subscription, we can download real time corrections directly from the Ordnance Survey (OS) whilst on site. All of our surveys are in accordance with RICS specification and the TSA best practice guidelines.
We provide hydrographic surveys such as river cross sections and bathymetric surveys of reservoirs and canals. Our surveys are undertaken using a remote control survey boat known as a HyDrone-RCV. From the safety of a bridge or cycle path, our surveyors can drive the boat remotely whilst the unit scans the bed using a SonarMite echosounder. Together with a Trimble R10 GNSS receiver, we can accurately plot the location of each measurement along with a depth to accurately map under water. From this data, we can produce river cross sections, DTMs or volume calculations. Our surveyors are RYA trained if a survey vessel is required.
UAV / DRONE SURVEYS
Sigma Surveys has invested in DJI Inspire Drones with Zenmuse X5s camera. Our PfCO CAA approved surveyors can map out areas of land or buildings and using photogrammetry, stitch the high-resolution photographs together in PIX4D. We install Ground Control Points (GCPs) and coupled with the use of Trimble R10 GNSS receivers to provide centimetre accuracy, the result is the best possible images and the ability to georeference the images / orthophotos / model to Ordnance Survey grid and datum.
SITE ENGINEERING SURVEYS
Our site engineering surveys are generally undertaken using a combination of Trimble S6 / S7 total stations and Trimble R10 GNSS receivers. Our total stations are fully robotic, therefore our engineers are in complete control of field survey / data coding etc.. Our GNSS receivers capture data from GPS / GLONASS / Galileo / Beidou satellites to provide the best accuracy possible. Together with a VRS Now subscription, we can download real time corrections directly from the Ordnance Survey (OS) whilst on site. This enables us to provide accurate setting-out positions, volume calculations and as-built surveys for example.
At Sigma Surveys we take precise monitoring very seriously. We have invested in the highest accuracy digital levels and high precision total stations. The Trimble S8 is the most advanced total station platform utilising various technologies to ensure accuracy and consistency between results. Whether monitoring the movement of an L-Bar prism or retro target, the Trimble S8 will provide consistently superior readings than any other total station on the market.
Results can be uploaded to the cloud and shared between consultants using Trimble’s T4D Lite software – utilising a very user-friendly interface.
Other aspects of monitoring include Tell-tales / crack monitors, tilt sensors and vibration monitors, all of which can be provided and installed by our survey team.
Monitoring can also be undertaken using 3D laser scans by comparing pointcloud data sets from varying dates. By controlling both sets of pointcloud to the same grid, our software can compare the differences and produce a model outlining any movement or bulging for example. The 3D pointcloud can also be used to draw vertical profiles through an external façade to display plumbness of the building.
UNDERGROUND UTILITY SURVEYS
Underground utility surveys are undertaken using a combination of Radiodetection CAT scanner and Mala Ground Penetrating Radar (GPR). Cable and pipe routes will be traced and marked on the ground using various colours of paint depending on utility type. Once all routes that can be located have been detected, the marks are surveyed using a total station, GPS or Drone and overlaid onto an existing topographical survey or OS background.
We can collate statutory records from service providers as part of a desktop study if required.
All of our surveys are in accordance with BSI PAS128 and the TSA best practice guidelines.