Presentation, embedded below was developed to bring users up to speed in interpretation of their resistivity data. Class for end users was conducted in Indonesia and included training on field data collection with SibER-48 using 900 m long profile in Wenner-Schlumberger and pole-dipole (remote electrode) 2D tomography.
On the second day users received hands-on instructions on data import into RES2DINV software, quality assurance of the data based on visual approach as well as through RMS of the interpretation model. General discussion about non-uniqueness of the subsurface interpretation model for 1D, 2D, and 3D representations has followed this class. No notes for slide. For IP surveys using the dipole-dipole array, one common method is to place the plotting point at the intersection of two lines starting from the mid-point of the C1-C2 and P1-P2 dipole pairs with a 45-degree angle to the horizontal. It is important to emphasize that this is merely a plotting convention, and it does not imply that the depth of investigation is given by the point of intersection of the two 45 angle lines (it certainly does not imply the current flow or iso-potential lines have a 45 angle with the surface).
How to use x2ipi with Res2dinv format data (Geotomo software, Malaysia). Res2dinv format is the main format ERT data. X2IPI – User Manual 2017.
Surprisingly, this is still a common misconception, particularly in North America! Training on RES2DINV and SibER-48. 1. Training on RES2DINV/RES3DINV software (Geotomo software, Malaysia) LARISA GOLOVKO, PH D LANDVISER LLC HOUSTON, TX. Materials need Each participant need to bring laptop! Copy folder 1RES2DINV to each laptop: Two.d2d files with data from yesterday Software installs Manuals for SibER-48, RES2DINV, RES2DMOD Off-line instruction pages from www.landviser.net Dr.
Loke’s Course Notes on Theory of 2D&3D resistivity surveys Install software: SibER Tools RES2DINV, etc.
Formatting Array Input Data File in RES2DINV: surface electrodes for any geometry Example of electrodes arrangement and measurement sequence that can be used for a 2-D electrical imaging survey is shown on the left. Many different multi-electrode systems have been developed over the past 15 years using different arrangements of the cables and measurement strategies (Loke, 2011). This program is designed to invert large data sets (with about 200 to 100000 data points) collected with a system with a large number of electrodes (about 25 to 16000 electrodes). The survey is usually carried out with a system where the electrodes are arranged along a line with a constant spacing between adjacent electrodes. However, the program can also handle data sets with a non-uniform electrode spacing. RES2DINV program can be used for surveys using the Wenner, pole-pole, dipole-dipole, pole-dipole, Wenner-Schlumberger, gradient and equatorial dipole-dipole (rectangular) arrays.
In addition to these common arrays, the program even supports non-conventional arrays with an almost unlimited number of possible electrode configurations (Loke et al. You can process pseudo sections with up to 16000 electrode positions and 70000 data points at a single time on a computer with 4 gigabytes (GB) of RAM.
Besides normal surveys carried out with the electrodes on the ground surface, the program also supports aquatic and cross-borehole surveys. The apparent resistivity values (and IP) used by RES2DINV software are given in a text file with.DAT extension. You can use any general purpose text editor, such as the Windows Notepad program if you are creating the data file manually. Some tips on using Windows Notepad for simple text file editing can be found here.
The data are arranged in an ASCII delimited manner where a comma or blank space or LF/CR is used to separate different numerical data items. If there is a problem in running RES2DINV software, one possible cause is that the input data were arranged in a wrong format. There are two main types of data format used by RES2DINV, an index based and a general array format. The older index based format is only used for conventional arrays such as the Wenner, Wenner-Schlumberger, pole-pole, pole-dipole and dipole-dipole arrays. The general array format can be used for any array, including gradient and non-conventional arrays of any configuration. Information below is compiled from RES2DINV Manual and Loke’s Course Notes to facilitate data file preparation and usage in RES2DINV for beginners.
Therefore, the Table and Figure numbering was kept constant with originals, which can be downloaded as full PDFs from the attachment to this blog post. A description of the different arrays types is given in the free tutorial notes on electrical imaging (Loke, 2011). Table A.1 shows the arrangement of the electrodes, names and codes for some commonly used arrays. In general for an array with four electrodes, there are three possible arrangements for the electrodes. The Wenner array has three different variations (Figure A.1).
The 'normal' Wenner array is actually the Wenner alpha array. The Wenner beta array is a special case of the dipole-dipole array where the 'n' factor is always 1. The RES2DINV program will automatically convert a Wenner beta array data file into a dipole-dipole array data set. A list of the arrays supported by the RES2DINV program together with their number codes are given below.