Hybrid inversion of shallow geophysical data for the location of subsurface targets

Abstract

In order to rapidly, safely and economically gather data about a waste site, nonintrusive shallow geophysical sensor technologies are used to map the surface of a site. The major thrust of this investigation is to locate buried man-made material (such as 55-gallon steel drums), using nonintrusive shallow geophysical methods. Two sensor data sets are dependently optimized to determine the six free parameters describing rectangular bounding boxes which totally encompass subsurface targets. A conservative bounding box approach is used to estimate the location and volume of the waste, but does not yield an unacceptably large volume to be remediated. This hybrid inverse approach has proven to facilitate solving problems involving nonuniqueness issues, as well as significantly reduce execution time. The two geophysical sensors employed in this investigation are the total field cesium vapor magnetometer and the EM61 time domain sensor. Results from data sets surveyed at a site at Sandia National Laboratories, in Albuquerque, New Mexico are presented.

Keywords:

• Hybrid inversion
• geophysical data analysis
• subsurface characterization

^†Corresponding author.

^†Corresponding author.

Notes

^†Corresponding author.