Accident Reconstruction & Forensic Measurement
iWitness and iWitnessPRO are extensively used for traffic accident reconstruction and forensic measurement, with photogrammetric technology being equally applicable outdoors or indoors, with photography from the ground or from UAVs (drones). Notable advantages of the iWitness approach include:
- Fast scene recording leading to minimal road closures & less traffic disruption
- Photography offers a permanent record; feature measurement at any time
- Technology is very low-cost; can use any camera
- iWitness is very easy to use & provides fast & accurate 3D measurements
- Operational scenarios: manual through semi- to fully automatic
- Data redundancy affords robust and reliable quality measures
iWitness has been adopted as standard approach for accident reconstruction across multiple states and 100s of police departments in North America and internationally.
Traffic accident reconstruction
Automatic 3D reconstruction of a boot print for forensic analysis
Architecture, Archaeology & Heritage Documentation
iWitness and iWitnessPRO are both ideal 3D measurement tools for a wide range of 3D measurement and modelling tasks in architecture, archaeology & heritage recording in general. The recognised attributes of photogrammetry for these applications centre upon the rapid, non-contact nature of the photography; the fact that scenes can be comprehensively recorded with image measurements being possible at any time; and the ease of use of iWitness-based measurement, which need not require more than a consumer-grade camera to support operational scenarios ranging from manual feature measurement to fully automatic 3D object reconstruction. These attributes are exemplified by the modelling of the Holsten Tor in Luebeck, shown below.
Automatic 43-image all-around modelling of the Holsten Tor, Luebeck
Bet Giorgis Church, Lalibela, Ethipoia
Automatic orientation of 23-image, 46,000-point Salzspeicher network with subsequent ‘dense’ reconstruction
Australis and iWitnessPRO are applied in engineering for purposes ranging from design and as-built surveys through to deformation measurement where the automatic measurement functions of iWitnessPRO are especially beneficial. Accuracies to around 1:50,000 are attainable via Australis’ automatic 3D measurement process when targets and a good quality DSLR camera are utilised.
Monitoring the deformation of a brick wall structure under different load conditions
Deformation measurement of a historic railway bridge
As-built measurement of a stairway for chairlift design and installation
Deformation measurement of brick paving under different lateral load conditions
Surveying & Mapping
iWitness is used by surveyors primarily for feature surveys, and often to generate 3D coordinate data to support building and planning approval processes. Measurement of 3D feature points by iWitness in local surveys requiring modest accuracy is often faster than via a total station, especially when point numbers run into the hundreds.
iWitnessPRO-Agilis, on the other hand, is most suited to the automated generation of 3D surface models and associated rectified and orthorectified imagery, and it is an ideal tool for localised mapping from photography gathered by a UAV (drone), where digital surface models (DSMs) and orthoimagery are generally sought. Moreover, iWitnessPRO-Agilis supports monoplotting such that once an underlying DSM or point cloud is available, 3D feature point coordinates can be recorded from single images forming the network.
Aerial survey from a UAV using iWitnessPRO-Agilis: auto-orientation and sparse point cloud generation (left) and textured 3D model formed by draping the generated orthoimagery over the DSM formed by dense image matching (right)
Feature point survey to support a building approval process
General 3D Measurement & Modelling
For objects large and small, far and near, recorded with sequences of frame images or video, iWitness, iWitnessPRO, iWitnessPRO-Agilis and Australis offer the full range of easy-to-use image-based 3D measurement functions for a wide range of further applications in areas such as mining, construction, medicine, ecology and the film industry. Prospective users can contact Photometrix should they have questions about the suitability of the iWitness and our range of products for a prospective 3D coordinate measurement, modelling or mapping task.
From Space …
3D terrain modelling from Mars Lander imagery
…to very small objects…
3D modelling of the surface of a coin