One of the specialities of Ireland Aerial Imagery is the planning and collection of data for the purpose of generating 3D Digital Surface Models (DSMs) and 3D reconstructions of features of interest. Utilising an approach known as Structure from Motion Photogrammetry (SfM) Ireland Aerial Imagery can construct 3D models from drone based imagery across a range of landscape types and sizes. By incorporating GPS or Total Station data into the collection process DSMs can be generated at survey quality.
Niall, the owner-operator of Ireland Aerial Imagery has had a decade of experience collecting and processing this kind of imagery for numerous projects in Ireland, the UK and New Zealand.
Depending on the resolution, or Ground Sampling Distance (GSD), required for a project, a series of flights will be created in specialist software. These preprogrammed flights will have the predetermined requirements for the project, the flying altitude, the uav speed, and the image acquisition rate. The benefit of this preprogrammed approach is that it affords the opportunity of systematic monitoring if required, as the same series of flights and settings can be undertaken repeatedly.
Generating 3D models through SfM photogrammetry works in a similar manner to human eyes. By identifying common points (tie points) across multiple 2D images, a 3D reconstruction can be generated. Since overlapping imagery is the key to successfully generating these models preplanning of operations is hugely important.
Once imagery has been acquired, another specialist software is used to generate a 3D point cloud. Depending on the size of an area being surveyed these point clouds can contain hundreds of millions of individual x, y, z observations. This is basis for all of the final products. This is computationally intensive work requiring high end computing hardware which Ireland Aerial Imagery provides.
This dense point cloud is what the final products are produced from. DSMs, photo realistic reconstructions and orthomosaics can be incorporated into a traditional surveys, cartographic production or used as stand alone products. These products can also be utilised within Google Earth or GIS software for further analysis.