Calculate Forward Model

Use the Calculate Forward Model option (Geosoft.uxo.gxnet.dll(Geosoft.GX.UXO.UxaCalculateForwardModel;Run)*) to calculate a forward model reference response of static or dynamic (multi-shot) measurements. You can configure up to six TOI items and calculate their responses for a specified sensor configuration.

Expand to see the locations (menus) where this option is available.

Calculate Forward Model dialog options

Sensor

Model

Select the sensor model (type). The values are read from the sensor configuration table; refer to the Application Notes below.

Script Parameter: UXACALCFRW.MODEL

Configuration

Select a configuration for the selected sensor model. The values are read from the sensor configuration table; refer to the Application Notes below.

If the Model field is set to "All", the Configuration list will contain the configurations for all the sensor models.

Script Parameter: UXACALCFRW.SENSOR

Height above ground (m)

Specify the height of the sensor above the ground surface, i.e., the "Height of Transmitter Assembly above ground". This is used to determine the height of the receiver coils above the ground, which is the sum of "Height of Transmitter Assembly above ground" and "Height of Z Coil above the Transmitter Assembly". For example:

Sensor	Height of Transmitter Assembly above ground (m)	Height of Z Coil above the Transmitter Assembly (m)	Height of the EM receiver coils above the ground surface
TEM2x2	0.2	0	0.2
MetalMapper	0.16	0	0.16
MetalMapper2x2	0.26	0.05	0.31

The height should be between 0 and 2 metres.

Script Parameter: UXACALCFRW.HEIGHTABV

Survey

Survey type

Dynamic

Select this option to calculate the forward model for dynamic (multi-shot) measurements.

Script Parameter: UXACALCFRW.SURVEYTYPE [DYNAMIC (default)]

Static

Select this option to calculate the forward model for static measurements. The Line/Station spacing parameters are disabled for this option.

Script Parameter: UXACALCFRW.SURVEYTYPE [STATIC]

Line spacing (m)

Specify a value between 0.00 and 10.00 for the line spacing. The default is 0.8 times the maximum of the transmitter coils LengthX or sum of LengthXs.

Script Parameter: UXACALCFRW.LINESPCN

Station spacing (m)

Specify a value between 0.00 and 10.00 for the sample spacing along the line. The default is 0.2 times the maximum of the transmitter coils LengthY or sum of LengthYs.

Script Parameter: UXACALCFRW.STATIONSPCN

Data chip size

Specify the data chip size. This is the window over which the forward model will be calculated:

Across line (m)

Enter a number from 0.00 to 100.00. The default for a Dynamic survey is three times the line spacing. For a Static survey, the default is the maximum of the transmitter coils LengthX or sum of LengthXs.

Script Parameter: UXACALCFRW.ACROSSLINE

Along line (m)

Enter a number from 0.00 to 100.00. The default (Dynamic and Static surveys) is the maximum of the transmitter coils LengthY or sum of LengthYs.

Script Parameter: UXACALCFRW.ALONGLINE

This window bounds the locations where you will be able to place the TOI. An additional two lines are added beyond the data chip extent to limit edge effects.

Library Database

Name

Use the browse button or the drop-down arrow to select the signature library database. The library database must contain the following channels:

UXA_FIT_B1
UXA_FIT_B2
UXA_FIT_B3
UXA_GATECENTERS

A warning tooltip will be displayed if the pulse length of the library data and the sensor configuration differ by more than 15%.

Script Parameter: UXACALCFRW.LIBRARYDB

Group

Select the TOI library group.

Default: the first group (line) in the selected library database.

Script Parameter:UXACALCFRW.LIBRARYGRP

Mask

Select a mask channel. When this channel is set to 1, the action will be performed on the data entry; if the value is set to 0 or dummy (*), the corresponding data entry will be ignored.

Script Parameter: UXACALCFRW.LIBRARYMASK

TOI class channel

From the library list, select the channel that contains the TOI types. This channel will filter the TOI list, making it easier to find and select the TOI items.

Default: UXA_Class (if the channel exists in the database)

Script Parameter: UXACALCFRW.LIBRARYCLASS

TOI description channel

Select the channel that contains the name or description of the items. This channel must contain unique values for each library item – typically this is the Library ID channel.

Default: UXA_LIBRARY_ID (if the channel exists in the database)

Script Parameter: UXACALCFRW.LIBRARYDESCRIPTION

Output database prefix

Specify the prefix for the output databases (see the Application Notes below for further details).

The drop-down list is populated with the prefixes of the static/dynamic databases that reside in the current project; the list is filtered based on the Survey type selection. Selecting an existing prefix will run the tool on the databases corresponding to the selected prefix; no new databases will be created.

Script Parameter: UXACALCFRW.OUTPUTPREFIX

Group

Specify the name that will be applied to the groups generated in the output databases:

Static survey: the group naming is applied to the Target and Seed databases.
Dynamic survey: the group naming is applied to the Parameter and Seed databases.

You can also select an existing group available within the databases, from prior runs: the drop-down list is populated with the groups associated with your current Output database prefix selection.

Script Parameter: UXACALCFRW.OUTPUTGROUPPREFIX

TOI

TOI Items

Configure up to six items

Class

You can select a specific TOI type from the list or keep the default entry "All". The list is populated with the values of the TOI class channel.

Script Parameter: UXACALCFRW_TOI_#.CLASSTOI

Item

Select the TOI name/description from the list. The list is filtered based on the selected Class entry. If "All" is selected, the list will contain all the entries from the description channel.

Default: the first entry in the list

Script Parameter: UXACALCFRW_TOI_#.ITEM

X Offset (m)

Specify the X coordinate of the middle point of the target window (± 0.5 times the chip size across line).

Default: 0.00

Script Parameter: UXACALCFRW_TOI_#.X_OFFSET

Y Offset (m)

Specify the Y coordinate of the middle point of the target window (± 0.5 times the chip size along line).

Default: 0.00

Script Parameter: UXACALCFRW_TOI_#.Y_OFFSET

Depth (m)

Enter the TOI depth below the ground surface. The depth should be between 0 and 10 meters.

Default value: 0.01

Script Parameter: UXACALCFRW_TOI_#.DEPTH

Inclination

Select an option for the item's inclination:

Horizontal (0^o)
Inclined 45 (45^o)
Vertical (90^o)

Default: Horizontal

Script Parameter: UXACALCFRW_TOI_#.INCLINATION [0: Horizontal (default); 45: Inclined 45; 90: Vertical]

Declination /azimuth

Select an option for the declination of the item:

In-Line (default)
Inclined 45
Cross-line

Default: In-line

Disabled when the Inclination is set to "Vertical".

Script Parameter: UXACALCFRW_TOI_#.DECLINATION [0: In-line (default); 45: Inclined 45; 90: Cross-line]

[Restore Defaults]

Click on the Restore Defaults button to return all of the parameters to their default values.

Application Notes

The tool will generate a TOI reference database of the forwarded model response of the selected item(s). This can help you better understand the theoretical response you can expect to measure for TOI. In addition, for static data this can be used with the Background Location Validation Test when trying to determine suitable background locations and the detectability of a TOI at your site.

The response is first determined for each configured TOI item. Then, the combined response of the TOI items is calculated.

When calculating the response, to help prevent two items occupying the same space, the position (X offset, Y offset and Depth), orientation (Inclination and Declination), and size of the items (the UXA_Dimensions field in the library database) are checked, and a warning is issued if two or more items do occupy the same space.

The following dynamic (DMD) /static (SMD) databases are created:

[DBPREFIX]_DMD/SMD_Data: contains the calculated response data.
[DBPREFIX]_DMD/SMD_Source: contains a copy of the polarizabilities and other information from the library. An entry for each forward model and TOI item is created. The channel UXA_Description is populated with the individual TOI items descriptions.
[DBPREFIX]_DMD/SMD_Target: contains any target or parameters information. A single entry is created for each run. The channel UXA_Identifcation is populated with compounded UXA_Description values and prefixed with the UXA_Target_ID values for the static option. The channel UXA_NumTOIItem records the number of TOI items.
[DBPREFIX]_DMD_Parameter - contains information for each survey line.
[DBPREFIX]_DMD_Located - contains information for each survey line and receiver version number.

The dynamic option does not support multiple models/runs in a single set of databases: the DMD databases will be overwritten when the GX is executed against the same output databases.

Sensor Table

The sensor configuration parameters are read from the sensor table: the default sensor table file "SensorTableAdvanced.xml" is in the "C:\Program Files\Geosoft\Desktop Applications \etc" folder.

To add new sensors or configurations to the table, you can use the Add Sensor Configuration tool. The edited file is then saved in the "%USERPROFILE%\Documents\Geosoft\Desktop Applications \etc" folder.

UX-Analyze Configuration File

The configuration file contains various default or standard settings for the tools. It is recommended that you edit this file only if directed by Support. The file, "uxa.config", is in the "C:\Program Files\Geosoft\Desktop Applications \etc" folder.