Characterization of Cavities Using the GPR, LIDAR and GNSS Techniques

Abstract

The study of the many types of natural and manmade cavities in different parts of the world is important to the fields of geology, geophysics, engineering, architectures, agriculture, heritages and landscape. Ground-penetrating radar (GPR) is a noninvasive geodetection and geolocation technique suitable for accurately determining buried structures. This technique requires knowing the propagation velocity of electromagnetic waves (EM velocity) in the medium. We propose a method for calibrating the EM velocity using the integration of laser imaging detection and ranging (LIDAR) and GPR techniques using the Global Navigation Satellite System (GNSS) as support for geolocation. Once the EM velocity is known and the GPR profiles have been properly processed and migrated, they will also show the hidden cavities and the old hidden structures from the cellar. In this article, we present a complete study of the joint use of the GPR, LIDAR and GNSS techniques in the characterization of cavities. We apply this methodology to study underground cavities in a group of wine cellars located in Atauta (Soria, Spain). The results serve to identify construction elements that form the cavity and group of cavities or cellars. The described methodology could be applied to other shallow underground structures with surface connection, where LIDAR and GPR profiles could be joined, as, for example, in archaeological cavities, sewerage systems, drainpipes, etc.

Integrated Approach to Investigating Historic Cemeteries

“…We performed a two-dimensional (2D) Kirchhoff migration before and after SVD using a constant ground velocity (0.16 m/ns calculated from diffraction hyperbola fitting). It has been shown that TLS can be utilized to determine a best fit ground velocity [24]. However, that is only possible when TLS data have captured subsurface structures (e.g., a cave or tunnel).…”

“…Global Positioning Systems (GPS) can be paired with GPR equipment to synchronously collect geospatial and geophysical data. It has been shown that high-precision height information is valuable in archaeological settings e.g., [21][22][23][24][25]. Digital elevation models (DEM) derived from airborne laser scanning (ALS) datasets can provide full coverage of a survey area (ALS is also referred to as airborne Light Detection and Ranging or airborne LiDAR).…”

“…Digital elevation models (DEM) derived from airborne laser scanning (ALS) datasets can provide full coverage of a survey area (ALS is also referred to as airborne Light Detection and Ranging or airborne LiDAR). Elevation can also be extracted from point cloud data e.g., [24][25][26][27] to perform a topographic correction of GPR data. Alternatively, elevation models derived from terrestrial laser scan (TLS) data provide a higher horizontal and vertical resolution that can reveal subtle mounds or depressions that may correspond to subsurface features [28].…”