Photogrammetry, Remote Sensing and the Surveying Discipline

摘要

For over a century, photogrammetry has been at the very heart of the surveying discipline and map-making process. In New Zealand, aerial surveys have been used to create topographic maps since the late 1920s. As imaging capabilities have dramatically improved through the development of new sensor technologies (e.g., digital sensors), and satellite platforms now enable observations to be made from space with unprecedented resolution, the means to obtain topographic information over large areas have evolved. New techniques, such as LiDAR, have gained a large momentum over the last decade. However, the principles of photogrammetry, which remain relevant, have also evolved. The Multiray photogrammetric technique now allows dense and accurate point clouds to be derived from multiple image overlaps and is competitive with LiDAR products. New platforms such as Unmanned Aerial Vehicles (UAV) offer new opportunities for surveyors, as many can now engage in aerial mapping without the logistical burden of aeroplane operations. Furthermore, imaging of the earth's surface from space via optical or radar technologies, offers spatial resolutions that now approach the requirements of some surveying tasks. In this context, the photogrammetric method has greatly evolved, becoming part of the wider discipline of remote sensing, placing it at the centre of the surveying profession. This paper offers a brief overview on how the discipline of remote sensing has gone hand in hand with land surveying, and what it can offer in the future to this profession.