OR/15/057 Visualising the data

From Earthwise
Jump to: navigation, search
Jones, L D. 2015. Ground-based geomatic surveys at the BGS - a manual for basic data collection & processing (2015). British Geological Survey Internal Report, OR/15/057.

The BGS has a number of high-specification PC’s capable of handling the acquired digital data, including a dedicated data processing PC (WSB, Upper Ground Floor, East). Software to process and output the acquired survey data is listed below. With the exception of Virtalis GeoVisionary and Esri ArcGIS, all these proprietary processing and visualisation software packages fall under single user license restrictions, and as such are either loaded onto dedicated PC’s or controlled by ‘dongle’ technology.

  • Riegl RiScanPro (Acquisition & processing VZ scanner data)
  • Riegl RiProfile (Acquisition & processing LPM scanner data)
  • Leica Geo-Office (Post-processing GNSS data)
  • Golden Software Surfer (Gridding scanner data)
  • Innovmetric Polyworks (Change models & cross-sections)
  • Bentley Pointools (Visualisation of point-cloud data)
  • Paradigm GOCAD (Integration with other surfaces e.g. GPR)
  • Applied Imagery Quick Terrain Modeler (3D model creation)
  • Esri ArcGIS (2D mapping and visualisation)
  • Virtalis GeoVisionary (3D mapping and visualisation)
  • Split-FX (Rock-fracture analysis)
  • Golden Software Voxler (3D visualisation)

In order to get the most out of your data a selection of the above software packages will need to be used. The following is a suggested workflow for the construction of 3D models:

GNSS data

Leica geo-office

  • Import GNSS data into Leica Geo-Office
  • Convert co-ordinates to Local Grid
  • Export as ASCII (*.csv) file

Lidar data

RiProfile

  • Carry out ‘Backsighting’ orientation and ‘Alignment’ for all scan locations
  • Save SOP positions to MATRICES folder
  • ‘Colour from images’ to create coloured point cloud
  • Create ‘Panorama’ images
  • Modify SOP using Polyworks image files
  • Export data as ASCII (xyzi or xyzRGB) files using global co-ordinates

Polyworks

  • Import Riegl project from RiProfile
  • Choose ‘best’ scan and ‘lock’ it. ‘Ignore’ all but one other
  • Carry out ‘Best-fit’ alignment
  • ‘Lock’ this scan and carry out process again (with third scan)
  • Highlight all scans and ‘auto-match’ to ‘Global reference points’
  • Export ‘Alignment Matrices’ to MATRICES folder

RiScanPro

  • Carry out ‘Backsighting’ orientation and ‘Alignment’ for all scan locations
  • ‘Colour from images’ to create coloured point cloud
  • Create ‘Panorama’ images
  • Carry out Scan Registration (Plane Filter and MSA)
  • Export data as ASCII (xyzi or xyzRGB) files using global co-ordinates

Modelling and visualisation

Polyworks

  • Import ASCII file
  • Create a mesh (triangulate scan)
  • Convert to ‘Reference’ object
  • Do change models (if required)

QT Modeller

  • Import ASCII file
  • Cut to size (if necessary)
  • Match model altitudes — this should already be done
  • Merge models
  • Create surface
  • Do change models (if required)
  • Export as Z-Map

Surfer

  • Import ASCII file
  • ‘Grid’ the data using either the Kriging, Nearest Neighbor or Triangulation with Linear Interpolation method
  • Create a Contour map. Create a Base map. Create a Post map (save this as a *.shp file)
  • Create a ‘Wireframe’ model from the grid data to drape the previous maps on
  • Create a Surface map
  • Export maps

GeoVisionary

  • Use PointCloud Tool to convert ASCII or LAS files into DAT file
  • On the 3D+ Tab Right-Click PointClouds and choose Add PointCloud
  • Navigate to the DAT file and click Open
  • Refer to GeoVisionary notes

Split-FX

  • A User Guide (written by D Boon) is appended to this report (Appendix 2).