English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The extended Born or localized nonlinear (LN) approximation of integral equation (IE) solutions has been applied to inverting crosshole EM data using a cylindrically symmetric model. The LN approximation is less accurate than a full solution but much superior to the simple Born approximation. Moreover, when applied to the cylindrically symmetric model with a vertical magnetic dipole source, the LN approximation works well because electric fields are scalar and continuous everywhere. One of the most important steps in the inversion is the selection of a proper regularization parameter for stability. The LN solution provides an efficient means for selecting an optimum regularization parameter, because Green’s functions, the most time consuming part in IE methods, are repeatedly re-usable throughout the selection process. In addition, the IE formulation readily contains a sensitivity matrix, which can be revised at each iteration at little expense. This fast inversion scheme has been tested on its stability and efficiency using synthetic and field data.

A Fast Inversion Method for Interpreting Crosshole Electromagnetic Data