Mathias Lemmens – författare

This book provides vital knowledge about the fundamentals, idiosyncrasies and unparalleled potential of point cloud technology and is an indispensable aid to acquiring competent knowledge on the processing steps necessary for converting raw data into high quality 3D geo-information.There is an enormous need to map cities, rivers, coasts, roads, industrial installations and infrastructure in general, and also vulnerable areas in full three dimensions. It has to be done accurately and in detail. The main technologies for detailed 3D mapping are based on imaging devices (photogrammetry) and Lidar sensors (laser scanning). These geodata acquisition technologies routinely acquire point clouds of billions of points and have matured rapidly since the mid-1990s. They have become key geodata sources for 3D city modelling, creation of digital twins and smart cities, and inspection of roads, railways, and natural features. Many GIS analysts extensively use point clouds in the form of digital elevation models.Pointcloudmetry is the specialized branch of geomatics that encompasses the acquisition and processing of point clouds captured by Lidar devices as well as point clouds derived from photogrammetric images.  The technology allows accurate and detailed geo-information about earth-related objects, including the bare earth surface, to be obtained. This book covers the entire chain from the principles of geo-referencing and the basics of electromagnetic energy up to the generation of 2.5D and 3D geoinformation.

Geomatics, the handling and processing of information and data about the Earth, is one geoscience discipline that has seen major changes in the last decade, as mapping and observation systems become ever more sensitive and sophisticated. This book is a unique and in-depth survey of the field, which has a central role to play in tackling a host of environmental issues faced by society. Covering all three strands of geomatics - applications, information technology and surveying - the chapters cover the history and background of the subject, the technology employed both to collect and disseminate data, and the varied applications to which geomatics can be put, including urban planning, assessment of biodiversity, disaster management and land administration. Relevant professionals, as well as students in a variety of disciplines such as geography and surveying, will find this book required reading. This rapidly developing field uses increasingly complex and accurate systems. Today, technology enables us to capture geo-data in full 3D as well as to disseminate it via the Web at the speed of light. We are able to continuously image the world from space at resolutions of up to 50 cm. Airborne LiDAR (laser surveying) sensors can be combined with digital camera technology to produce geometrically correct images of the Earth's surface, while integrating these with large-scale topographic maps and terrestrial as well as aerial images to produce 3D cityscapes that computer users can explore from their desktops.