Articles in the Surveying Category
The methodologies of land surveying remained largely unchanged over hundreds, if not thousands, of years. Computational methods were enhanced with the use of logarithmic tables introduced by Napier in the 17th century, and supplemented by hand-powered rotational cylinder mechanisms for speed of calculation first introduced by Pascal, also in the 17th century. These were later to be electrified in the 20th century prior to the invention of the…
The main goal of the new phenomenon is the participation of the citizens. Everyone can be involved by collecting and uploading data or by editing entries and monitoring the results. Different terms are interlinked to it; User Generated Content, Crowdsourcing and Neogeography are only a few of them share the main philosophy.
Through all of these changes, there have been some fundamental challenges that seem to me to be an ongoing part of academic life in any professional school. They are challenges that seem to confront many university surveying programs in the world. These and the solutions that we have adopted are the subject of this article.
Virtual Reference System (VRS) comprises a network of three (3), or more, continuously operating Global Navigation Satellite System (GNSS) receivers, sited at points of known coordinates up to 70 Km apart and connected via data links. A control centre, with computer processing capability as well as a mobile phone data link, such as Global System for Mobile communication (GSM), is established for communication between the control centre and the users’ rover receivers.
The idea for designing unmanned aerial systems (UAS) for rapid mapping originated from a doctoral dissertation in aerodynamics by Peter Cosyn, one of the three founders and now Director of R&D at Gatewing. Maarten Van Speybroeck, Director of Operations and Finance, was involved with this idea as subject for a thesis.
GPR is a geophysical investigation method. Its principle is similar to that of Seismics but instead of emitting elastic waves, it emits electromagnetic waves. They are much shorter, which leads to a much higher spatial resolution. GPR is sensitive to the electromagnetic properties of the material under investigation. Interfaces of rock formations, fi ssures and aquiferous areas are displayed.
Geological researches have increased the utilization of tridimensional models in the last years in order to make possible visualization, parametrization and interpretation of data. The LIDAR technique allows to acquire a huge amount of georeferrenced data using a Terrestrial Laser Scanner (TLS). Both fastness and accuracy are the main characteristics of this equipment. Its utilization in geological studies has started in the last decade (Bellian et al., 2002), but only in the last years the number of scientifi c articles has increased signifi cantly. The TLS acquires georeferrenced point clouds that can be converted in digital models after processing, especially digital outcrop models (DOM).