Importing Induced Polarization Data

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Joan Carpenter
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1 Importing Induced Polarization Data This How-To Guide will introduce you to importing IP survey data. Using the Induced Polarization extension you can import a variety of data types, including: Instrument Dump files Geosoft IPDATA Geosoft IPRED Scintrex Geophysical Data format Zonge FLD files Zonge AVG files Zonge AVG (CRAVGW) files Interpex I2X format Instrumentation GDD format Gridded data files UBC IPINV2D/DCINV2D files 3D IP data files The Importing Induced Polarization Data guide will walk you through importing IP data, including: 1. Saving Database Changes 2. Creating a Windowed Channel from an IP Array Channel 3. Importing Frequency Domain Data 4. Sample IP Data Files Importing IP Instrument Dump Files Before you can begin you will need to import your IP data. The IP system can import data from instrument dump files directly into a Geosoft database. In the following example, we will demonstrate how to import a time domain instrument dump file. You can experiment importing data from an Iris Elrec-6 IP instrument (IP6.DMP) data file. Warning! If you have a database open, the new data is imported into that database overwriting any existing data. To Import a Time Domain Instrument Dump File 1. From the IP menu, select Import and then select IP Data. The Create New Database dialog appears. 1

2. Specify a New database name. 3. Click OK. The new database is opened in the background. The Import IP Data dialog appears. 4.

If you select Overwrite, all existing data are deleted from the database before the import is performed.

In our case, it is irrelevant as there is no pre-existing data. 6. Click Next. The Import IP Data from Dump File dialog is displayed. 7.

2 2. Specify a New database name. 3. Click OK. The new database is opened in the background. The Import IP Data dialog appears. 4. From the Import from dropdown list, select the format of the file to import as Instrument Dump File. 5. Select the Import mode entry. If you select Overwrite, all existing data are deleted from the database before the import is performed. If you select Append, the newly imported data are appended to the existing data, line by line. In our case, it is irrelevant as there is no pre-existing data. 6. Click Next. The Import IP Data from Dump File dialog is displayed. 7. Using the browse ( ) button, locate the Data file to import ( in this example IP6.DMP, which can be found in the Geosoft install folder "..\Geosoft\Oasis montaj\resourcefiles\data\ip"). 8. From the IP Instrument dropdown list, select the instrument type (in this example Iris Elrec-6). 2

You can accept the intelligent default values and click Finish to continue. The data are imported into the database and displayed in the spreadsheet pane.

3 9. Click Next. The Iris Elrec-6 Parameters dialog appears. The dialog varies based on the selected type of IP instrument. 10. Use this dialog to set the import file parameters that are not explicitly set in the import dump file. You can accept the intelligent default values and click Finish to continue. The data are imported into the database and displayed in the spreadsheet pane. Saving Database Changes The imported data resides in memory until it is committed to file (saved). While the information is in memory, although you see it in your project, it is not actually saved. It is a good practice to save your database immediately after importing it and avoid losing valuable work. 3

4 To Save Database Changes 1. From the Database menu, select Save Database Changes. The Save Changes dialog appears. You can also select the Save Database Changes icon on the main toolbar to save your changes. 2. Click Yes to save all changes to the current database. To revert back to the last saved version of the database you can use the Database / Discard Database Changes menu option or click the Discard Database Changes icon on the main toolbar. Creating a Windowed Channel from an IP Array Channel Use the windowing utility to create a new channel of IP values to store one or more of the windows in an array channel column. This utility is useful when you want to plot a single channel (from an array) in a pseudo-section. When plotting an array channel, the system averages the channel values and creates a new channel with the averaged values. For time domain array data, multiple channels are summed using a weighted average based on the width of each time window. For frequency domain data, values are simply averaged. To Window an Array Channel 1. In your IP database spreadsheet window, select the header cell for your IP array channel. Right-click and from the pop-up menu, select Array to Database Channels. The Array to Database Channels dialog appears. 4

2. Using the Array Channel dropdown list, you can select an array channel to window. 3. In the Array channel elements window, select the channels to add to the database and click the button.

5 2. Using the Array Channel dropdown list, you can select an array channel to window. 3. In the Array channel elements window, select the channels to add to the database and click the button. The channels will be added to the Database channels window. To remove channels from the Database channels window, select the channels to remove and click the button. 4. Click OK. The new channels are created in the database containing the average of the windowed values you specified. Closing Current Database When you are finished working with your current database, or are ready to import data into a new database, you can close your current database. To Close Current Database 1. From the Database menu, select Close Database. The Save Changes dialog appears. 5

6 2. Click Yes. The system updates and closes your database. Importing Frequency Domain Data The IP system can import data from a variety of instrument dump files, in the following example we in demonstrate importing a frequency domain data. Zonge IP Pole-Dipole IP survey. You can experiment importing data from a Zonge IP Pole-Dipole IP survey, by importing the "CRPD132.FLD" data file, found in the "...\Geosoft\Oasis montaj\resourcefiles\data\ip" folder. Warning! If you have a database open, the new data is imported into that database overwriting any existing data. To Import a Frequency Domain IP File 1. From the IP menu, select Import and then select IP Data. The Create New Database dialog appears. 2. Specify a New database name. 3. Click OK. The database is displayed in the background. The Import IP Data dialog appears in the foreground. 6

4. From the Import from dropdown list, select the format of the file you want to import. (In our example we selected the Zonge FLD Format.) 5. Accept the default in the Import mode entry.

7 4. From the Import from dropdown list, select the format of the file you want to import. (In our example we selected the Zonge FLD Format.) 5. Accept the default in the Import mode entry. If you select Overwrite, all existing data are deleted from the database before the import is performed. If you select Append, the newly imported data are appended to the existing data, line by line. In our case, it is irrelevant as there is no pre-existing data. 6. Click OK. The Import Zonge FLD Format File dialog appears. 7. Use the Browse button to select the Zonge FLD file to import. 8. From the Station Scaling dropdown list, select the scaling method. Sometimes, the station values represent actual distances and other times they may be simply sequential numbers. The Scale factor is only used when the Station scaling is set to Scale Factor 9. Click Finish. The data are imported into the database and displayed in the spreadsheet pane. If you are importing frequency data with more than one base frequency, an amplitude and phase channel are created in the database for each frequency. Depending on the survey instrument, the survey data might also have additional specialized channels not listed in the Database Channels table. 10. From the Data menu, select Save Database Changes. The Save Changes dialog appears. 7

8 11. Click Yes. All of your changes to the newly imported database will be saved. To revert back to the last saved version of the database, you can use the Database Discard Database Changes menu option. Sample IP Data Files This Sample IP Data Files section describes the survey parameters for each sample data file in the Induced Polarization system. These data files are installed in your../program Files (x86)/geosoft/resourcefiles/data/ip directory. The IP data directory contains a collection of files from a variety of instruments and data formats. Some formats can be imported directly into a Geosoft database. Others require some preparation involving setting default parameters, because the files do not contain all the information required during import. For the default setting procedure, see the Setting the IP Configuration section in the Getting Started Guide. If you do not edit the system default settings, the default values will be used (Dipole-dipole array, E-W line direction, distant electrode locations are assumed to be at infinity). Instrument Dump Files Iris Elrec-2 (Time Domain) Parameters to pre-set: Array Type, Line Direction IP2DPDP.DMP: Dipole-dipole data IP2GRAD.DMP: Gradient data IP2PLDP.DMP: Pole-dipole data Iris Elrec-6 (Time Domain) Parameters to pre-set: None IP6.DMP: Dipole-dipole This file is useful to demonstrate the pseudo-section and stacked pseudo-section plots because it contains a wellpopulated data set with four lines of data. IRIS6A.DMP: Dipole-dipole V9.1 format Iris SYSCAL-R2 (Time Domain) Parameters to pre-set: Line Direction 8

9 SDPDP.DMP: Dipole-dipole data SGRAD.DMP: Gradient data SPLDP.DMP: Pole-dipole data Scintrex IPR11 (Time Domain) Parameters to pre-set: Line Direction IPR-11.DMP Scintrex IPR12 (Frequency Domain) Parameters to pre-set: None IPR-12.DMP Phoenix V4-V5 (Frequency Domain) Parameters to pre-set: None V4.DMP Zonge Import Data Formats The Induced Polarization system supports import for two Zonge data formats: FLD and AVG. The FLD format is produced by running the Zonge program SHRED on the instrument dump files. The AVG format is produced by running the Zonge programs TDAVG (for time domain data) and CRAVG (for frequency domain data) on FLD format files. Both TD (time domain) and CR (complex resistivity, or frequency domain) versions exist for both the FLD and AVG files. Station numbering in Zonge files does not always correspond directly to station position in meters. In many cases, however, the station numbers may be converted directly into locations by multiplication with the A-spacing. For example, if A = 50, and the stations are numbered in Zonge as 0, 1, 2, and 3, the actual station locations will be 0, 50, 100, and 150. The conversion method is specified during the import process. Failure to set the conversion correctly results in nonsensical "N" and ResCalc (calculated resistivity) values in the database. Zonge FLD Format Parameters to pre-set: None CRDD921.FLD: Frequency Domain; A-Scaling; Dipole-dipole CRPD132.FLD: Frequency Domain; None; Pole-dipole SAMCR.FLD: Frequency Domain; A-Scaling; Dipole-dipole SAMTDIP.FLD: Time Domain; A-Scaling; Dipole-dipole TDIPDPDP.FLD: Time Domain; A-Scaling; Dipole-dipole TDIPGRD.FLD: Time Domain; None; Gradient TDIPPDP: Time Domain; None; Pole-dipole Zonge AVG Format Parameters to pre-set: Array Type, Line Direction CRDD921.AVG: Frequency Domain; A-Scaling; Dipole-dipole CRPD132.AVG: Frequency Domain; None; Pole-dipole SAMTDIP.AVG: Time Domain; A-Scaling; Dipole-dipole 9

10 TDIPDPDP.AVG: Time Domain; A-Scaling; Dipole-dipole TDIPGRD.AVG: Time Domain; Factor = 3.26 (see note below); Gradient TDIPPDP.AVG: Time Domain; None; Pole-dipole The distance units in the database are taken from the $ ASPACE line. If you want to use meters, convert the value in feet to the one in meters. For instance, in the TDIPGRD.AVG file, the A-spacing is given as 15 ft, but the station numbering is based on meters. To get correctly scaled station positions in feet the station numbers must be multiplied by If you want to use meters, edit the AVG file, and change the "$ ASPACE= 15.ft" line to "$ ASPACE= 4.6m", and use "None" for the station-position conversion. Publication Date: January Copyright 2016 Geosoft Inc. All rights reserved. 10

Processing your Induced Polarization Data

Processing your Induced Polarization Data This Processing your IP Data How-To Guide will introduce you to a variety of IP processing tools including how to: 1. Set up a database for IP processing 2. Adding