Michael Gallie & Partners specialise in providing point cloud surveys. Below is an outline guide of our process of producing a point cloud survey.
1.0 Survey Control Framework & Grid/Datum Setup
All our point cloud surveys are based upon an accurate survey control framework using the latest survey equipment in the market. To relate the survey to Ordnance Survey national grid and datum our surveyors use 2 No. high accuracy GPS receivers on-site simultaneously for a 2-hour period.
2.0 Laser Scanning
At Michael Gallie & Partners, we only use laser scanning for all our point cloud surveys. All areas of the building are fully laser scanned to ensure complete coverage. This involves a surveyor with a laser scanner mounted on a camera tripod carrying out multiple static setup positions across each floor typically for 1-2 minutes at a time. For some types of survey, we sometimes use a mobile hand-held laser scanner on-site for rapid but less accurate data collection. If you require a colour/RGB point cloud the site time for each static setup increases by at least 1 minute per setup. Mobile hand-held devices can take imagery simultaneously with the point cloud.
3.0 Office Processing to Produce Point Cloud
Using specialist software and high-end specification computers, the laser scan data collected on site is then processed and registered to the relevant site grid & datum. The resultant registered point cloud is checked, verified and exported in manageable floor by floor chunks ready for the modelling process. Where required we also export the HDR colour/Greyscale images and/or point cloud taken by the laser scanner to create a TruView of each setup position carried out on-site. TruView is a web-based viewer software that documents the whole site conditions using measurable 360° pano-tour images taken from the laser scanner, an especially useful tool during the Covid-19 lockdown restrictions.
4.0 BIM Production
The point cloud survey is then imported into the BIM authoring software i.e. Revit ready for the modelling process. Our modelling teams work collaboratively together on a single centralised model to avoid any repetition or modelling errors occurring. On each project the modelling team generally each work separately on different floors of the building and then synchronise back to the central model at suitable modelling milestones.
5.0 Client Issue
All point cloud survey deliverables are issued to the client via a weblink download. All 3D models issued are accompanied with a drawing register which indicates model issued, versioning, date of issue and people issued.
If you need any advice on commissioning a point cloud surveys, please contact Sam Lloyd at Michael Gallie & Partners who will be happy to assist you in this matter.