Half Schlumberger array is a kind of Pole-dipole array, a voltage-measuring pair of grounded potential electrodes separated successively from one current electrode (pole) while traversing a survey line. The second current electrode (the infinite electrode) is so far away that its location has negligible effect on the measurements. Data can be plotted below the mid-point between the current and the near potential electrode on a pseudosection, called a half-Schlumberger array.

This array allows to receive maximum geophysical information by multielectrode resistivity survey and to improve quality of interpretation, especially for the deepest part of geological section.

Basic work principle and application can be found from any standard geophysics book.

All the best.

Dear Diky

Go through the below link, it will help you more.

Regards

https://pubs.usgs.gov/bul/1313c/report.pdf