Basemap: Quick Grid and Contour Properties

Geoscience > Main Launcher > Launch Menu > Basemap > Additional Resources > Quick Grid and Contour > Properties

Quick Grid and Contour Properties

To define the quick grid and contour properties, use this page, which you can open using the icon ( ) or from the Tools menu.

Gridding

Keep and attach grid to project: This determines if gridding is to be performed, and if the result is to be attached. It is possible that gridding will still occur if this check box is off (e.g. for computing a residual) though the results will not be saved.

Technique: Select the desired algorithm. A brief description of the algorithm is provided under "Description of Technique". For more information refer to the Gridding Techniques in the Grid and Contour help.

Column width and row height: Specify the column width and row height in map units. this is either meters or feet depending on the coordinate system being used.

Smooth grid: Enable this to use a smoothing algorithm to eliminate spikes in the grid.

Gridding distance: The farthest distance the output grid will extend from any seed data point. When gridding 2D data or irregular 3D data this can be used when you don't want to fill in all the gaps. This value is specified in map units, usually meters.

Constraint Polygons (optional): Use this option to specify a region of seed points to use for the grid. If using an Inclusion/Constraining Polygon only the seed points within the polygon will be used to create the grid. If using an Exclusion/Constraining Polygon only the seed points not within the polygon will be used. This polygon will not affect the size or shape of the output grid.

Clearing Polygons (optional): Once the grid is created this polygon will be applied to clear parts of the grid. If using an Inclusion/Constraining Polygon all parts of the grid will be cleared except for what is within the polygon. If using an Exclusion/Constraining Polygon everything will be kept except for what is in the polygon.

Fault Polygons (optional): Use this option to define fault regions. When gridding seed data points that are across a fault they are ignored and not used to determine grid values.

Trend Bias

Use defaults: When searching for a set of points to consider when calculating the value for a grid node, this option tells it to search within a circle where the radius is one half the distance of the grid diagonal.

When using Kriging as the gridding method, you can specify the Search Ellipse and Anisotropy independently to skew the resulting grid.

For information on all parameters see the Anisotropy and Search Options page in Grid and Contour.

Contouring

Keep and attach contour to project: If the check is off, no contouring will occur. If contouring is necessary for an internal operation the results will not be preserved.

Use default intervals: If toggled on, the software will estimate an appropriate contouring interval. Turn off to manually specify the contouring intervals.

Smooth Contours: Indicates whether the contour should be smoothed or not. A smoothed contour will have more control points in it. You have the option to smooth a contour using a spline or using a grid method. When using a grid to smooth the line, the original grid is resized to 5 times its original size and then the contours are generated as normal, which produces a smoother line because the grid is finer. Using a grid to smooth the contours means that you will not get overlapping contours or loops happening where there are cusps in the contour line.

Thick Line Color: The color for the thick contour lines.

Thick Interval: Interval between each thick contour line. This should be a multiple of Thin Interval below.

Thin Line Color: The color for the thin contour lines.

Thin Interval: Interval between each thin contour line. If this value is too small, then the resulting output will be too dense. The contouring process will also take much longer.

Generate contour labels: Controls whether or not contour labels will be generated.

Label Distance: The distance on the same contour line that has to traverse before another contour label will be generated.

Label Interval: Interval value for each contour to be labeled. Typically, users set this to the same value as "Thick Interval". It is a good idea to set this to a multiple of "Thin Interval".

Label Font, Label Size: These control the appearance of the labels posted.

Num Decimals: The number of decimal places the contour labels will have.

Residuals

Create and attach surface trend: This option creates a trend surface. The trend surface is calculated using a polynomial regression algorithm to create a smooth surface that approximates the seed points. The higher the order of the polynomial used, the more closely the trend surface will match the seed points.

Create and attach residual: A residual surface is the difference between the trend surface and the gridded surface. The residual surface can show anomalies between the gridded surface and the trend surface.

Trend surface polynomial order: The order of the polynomial that will be used in generating the trend surface. The higher the order, the more closely the trend surface will match the seed points. Also, the higher the order, the longer it will take to calculate the trend surface.

Well Tops

Include well tops: To grid and contour well tops in conjunction with the seismic data, ensure that this is checked on.

Use shallowest value: In the case of multiple well tops values, only the shallowest one will be used.

Use deepest value: In the case of multiple well tops values, only the deepest one will be used.

Use all values: In the case of multiple well tops values, all data values will be used. This may result in averaging.

Also See

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