MultiLoop III - Tutorial 3 Creating a Grid & Plotting Vectors (Continued from Tutorial 2)

Step 1: Create the grid Complete Tutorial 1 and 2. Complete Tutorial 1 and 2. From the “Survey” menu, select “Edit Grids” From the “Survey” menu, select “Edit Grids” The “Define Grid” dialogue will appear The “Define Grid” dialogue will appear Enter the properties of the grid to create Enter the properties of the grid to create Select “New” Select “New” A grid will be created. A grid will be created. Go. Go.

From the “Survey” menu, select “Edit Grids ”

The “Define Grid” Dialogue appears, sensible default values will be computed. The grid location in space The coordinate on the grid located in space Orientation Length of the sides Calculated strike and dip Discretization Hatching and back-plane toggles Colouring options Grid selector Create a grid with the parameters given in the edit boxes to the right Replots the grid with the parameters selected, recomputes scattered vectors

Edit the reference point, rotations, strike length and dip extensions to parameterize the grid you want. …these parameters can be changed later, so don’t be too concerned to set them perfectly the first time through. When, done, click “New” to create the grid

When a new grid is created, the “Grid Selector” will need a name for it. A suggested name will be automatically generated. Set the name you want and click “OK” to create the grid. Often the suggested name will be good enough, and does not need changing. If a duplicate grid name is entered, a grid will not be created.

The new grid name appears in the grid selector

The grid should appear in the graphic window. If it does not, check the orientation and reference point parameters to ensure the grid is properly located. Check the strike length and dip extension to ensure the grid is the proper size. Hint: If the grid cannot be seen, Turn on the backplane to help locate the grid. Also check the “Show” option in the “Plot” menu, to ensure that grids are showing.

Step 2: Compute scattered fields Add hatching to the grid Add hatching to the grid Compute the scattered vector fields and view the default plot Compute the scattered vector fields and view the default plot Remove the profile plot from view Remove the profile plot from view Select a new channel to view as scattered vectors Select a new channel to view as scattered vectors Go Go

Click on “Hatching“ to add hatching

Hatch marks are then shown at the discretization points

Click “Update” to update the scattered vector fields on the grid.

A confirmation message will appear to confirm that the scattered vectors should be recomputed. Click “Yes”

The scattered vector fields are recomputed and plotted

To work more with scattered vectors, exit the “Define Grid” dialog

To remove the profiles from the display (the profiles will still exist, but will just not be shown), from the “Plot” menu, select “Show” and click on “Response Profiles”. This makes the display less cluttered, so working with the scattered vector plots is easier. This is done as a matter of convenience only. The Response Profiles can be redisplayed at any time by repeating this operation.

The profile plots are removed; the grid with the scattered vectors is easier to see.

To edit the scattered vectors, click “Vectors” on the “Plot” menu

This brings up the “Plot Magnetic Field Vectors” dialogue

Vector Data Selector: shows existing vector data Normalized or unnormalized vectors can be plotted The “Plot Magnetic Field Vectors” dialogue The scale sets the size of vectors plotted Vector plots can be created or deleted. Here are no vector data available to create a plot, so “Create Plot” is grayed out. Settings: “Auto” sets the scales and colours automatically Two vector fields can be overlain A 3-component (X,Y,Z) field is plotted No field is plotted in the second selection The vector plot can be hidden from view The vector field for channel “Eq_0” is plotted

To change the channel plotted, click on the button in the Channel column A “Select the gate name” dialogue will appear. Select the gate name from the list box Click “OK” when done

The vector field for the selected channel will be plotted

Step 3: Plot a second channel Select how the vectors will be plotted Select how the vectors will be plotted Select the channel to plot Select the channel to plot Go Go

To plot the second vector field, click on the Component, in this Case “No Selection” is showing A “Set Component” dialogue will appear. Select the component from the radio button list Click “OK” when done

As before, to change the channel plotted, click on button in the Channel column A “Select the gate name” dialogue will appear. Select the gate name from the list box Click “OK” when done

Two 3-component vector fields are now plotted The vector fields compare channels UT_6 and UT_1

Detail of the vector field To zoom in, use the magnifying glass or type “i” Each vector field is plotted with its own colour scheme. The colour used varies with the magnitude of the vector. Channel UT_6 is plotted in purple (large) and blue (small) Channel UT_1 large amplitudes are plotted in red, smaller amplitudes in purple