Window Solution List

Use the Euler 3D >  Window Solution List menu option (E3WINDOW GX) to remove certain solutions if they exceed acceptable limits of depth, weight, or other parameters.

Refine Solution List dialog options

Solution list	The Name of the "group" line with solutions. This value is the same as the most recently specified solution list from any of the other GXs that require a Solution List. Script Parameter: EULER3D.SOLUTIONS
Channel with results	Channel of data which is to be examined. Script Parameter: E3WINDOW.CHAN
Mask channel	The mask channel is updated by the windowing operation. The mask channel is used for selecting a subset of solutions from the solution list. This channel is initially set 1 to indicate that all solutions are selected. If the value is set to 0 or dummy (*), then this solution will be ignored in operations making use of the mask channel. Script Parameter: EULER3D.MASK
Mask results less than	Mask all the solutions where the data value in the selected channel is less than the specified value. If this value is left blank, no minimum value is enforced. Script Parameter: E3WINDOW.MIN
and greater than	Mask all the solutions where the data value in the selected channel is greater than the specified value. If this value is left blank, no maximum value is enforced. Script Parameter: E3WINDOW.MAX
Masking mode	The masking mode has two options: In the Append mode, the mask channel values are set to dummy ("*") for all values outside the specified range. No values are reset from dummy to 1 if they happen to be inside the range. In the Preset mode, the mask channel value of every item where there is valid data in the selected channel is first set to 1, and then the windowing is performed. (Solutions where the data channel value is a dummy will have the mask channel value dummy as well). Script Parameter: E3WINDOW.MODE 0: Append Mode, 1: Preset Mode.

Application Notes

The GX allows the user to window the solutions prior to creating a final solution list. This GX will apply a minimum and maximum cutoff to any single channel. The windowing works by updating the Mask channel. If a value is outside the specified range, the mask channel value is set to dummy "*". Working with a mask channel allows the full data set to remain unchanged, while allowing the user to select a subset of solutions for plotting.

The windowing may be performed on a number of channels in succession by using the Append mask mode. To restart the windowing process, you may manually reset the mask values in the Mask channel to 1, or you may run this GX using the Preset mask mode.

Generally the channels most commonly windowed are the depth and apparent weight values. The analytic signal amplitude channel is also windowed to remove values below a minimum threshold.

Typical Applications

Windowing on Depth (Z)

The user may not be interested in finding sources outside a certain depth range. Also, the width of the search window in E3DECON.GX determines the depth range for which solutions are meaningful. Although the relationship is complex and depends on the anomaly model used and the character of the data, generally solutions at depths much greater or much smaller than the width of the search window may be considered as errors, resulting from either multiple sources, a source which does not fit the model geometry, or else no significant source in the vicinity of the search window.

Windowing on X and Y Offset

Similarly to above, solutions lying too far from the centre of the search window are most likely errors resulting from the failure to find a single, clear anomaly that matches the model. Windowing on solution offset is particularly useful as a means of "focusing" the solutions onto the location of a real source. It may be used to help correct the scattering of solutions caused when the real source geometry differs from the model geometry chosen in E3DECON.GX. Windowing on Depth Uncertainty (dZ): E3DECON.GX allows the user to reject solutions with a depth uncertainty greater than a certain percentage (default 15%). However it is best not to set this parameter too low in E3DECON.GX, since it is easy to eliminate solutions afterward with E3WINDOW.GX, but the only way to add solutions is to run E3DECON.GX again, which is more time-consuming. Also the uncertainty is not necessarily the best criterion for rejecting solutions, since a geological anomaly may be important even if it does not exactly conform to the shape of the model anomaly used in E3DECON.GX.

Windowing on Location Uncertainty (dXY)

E3DECON.GX does not restrict the location uncertainty of output solutions, so it is generally a good idea to window on dXY with E3WINDOW.GX, in order to eliminate at least the worst cases for location uncertainty. However the maximum dXY limit need not be the same as the maximum dZ limit. For instance: if Euler deconvolution is being used to locate drill solutions, then the location error will likely be more critical than the depth error. Windowing on New Channels: The user may wish to add new channels to the solution database, in order to help select more meaningful or relevant solutions. For example, if geological information is available in digital format, then the user may create a geology channel, and then use E3WINDOW.GX to select only solutions lying within a certain formation.