To help determine optimal grid refinement and analysis of bathymetric data, Grid+ provides options for viewing elevation profiles of cross-sections such as DEMs (Digital Elevation Model), and TIN (Triangulated Irregular Network). This page describes the options for viewing elevation profiles for each data type.
View elevation profile of cross-sections
When a cross-section data file is available, it may be imported and view in Grid+. To do this, click the Import button from the main toolbar, then select Import Cross-Sections as shown in Figure 1. After selecting that option, the Import Cross-Sections form will be displayed. Browse to the cross-sections file, then select Open button as shown in Figure 2. The Coordinate System form will be displayed, and we must define the correct projection for the cross-section data file. Click the OK button to finish as shown in Figure 3.
After importing the cross-section data, to locate in the cross-section location, RMC on the XS layer in the Layer Control, then select Zoom to Layer as shown in Figure 4.
Figure 1 Import cross-sections option.
Figure 2 Import Cross-Sections form.
Figure 3 Define Coordinate System.
Figure 4 Zoom to Layer.
When the cross-section data file is opened in a text editor, it is seen that the last column (the third one) contains the elevation value, as shown in Figure 5. Based on these values, we a range for the elevation color ramp of the cross-section may be set. Press Alt + C on the keyboard, and the Specify Elevation form will be shown. Enter the minimum and maximum values in the form, then click the OK button as shown in Figure 6. The color ramp for cross-sections will be displayed as shown in Figure 7.
Figure 5 Elevation values in Cross-Section data file.
Figure 6 Enter elevation range.
Figure 7 Cross-sections color ramp.
Next, select the Selection mode by pressing the S key and then LMC on a cross-section to select it. Then its information is shown in the lower left corner as shown in Figure 8. Next, RMC to display options and select View Cross-section Profile as shown in Figure 9. The cross-section elevation profile is shown as the plot in Figure 10.
Figure 8 Select add a polyline option.
Figure 9 View Cross-section Profile.
Figure 10 Cross-section elevation profile.
There are three buttons on the Cross-section Elevation Profile which allows the saving of the profile out, as shown in Figure 11. They are described below.
| Option | Description |
|---|---|
| This option saves the profile to a file, which can be in *.txt or *.dat format. After saving the profile to an external file, open the file in a text editor. Four columns will be displayed. The first two columns are coordinates (X, Y), the third one is the elevation (Z), and the last one is the length (L) calculated from the starting point. |
| This is copy profile data button. Once this button is selected, the profile is copied to the clipboard and can be pasted to a text editor or Excel. The data contains two columns, one is X values, and the other is Y values of the plot. |
| This option allows saving the profile image to a file, which can be saved in different formats such as *png, *jpg, etc., as shown in Figure 12. |
Figure 11 Saving profile options.
Figure 12 Export cross-section profile image.
View elevation profile of DEM
Suppose that a DEM data file is available. Click the Import button from the main toolbar, then select Import DEM as shown in Figure 13. After selecting that option, the Import Overlay Layer form will be displayed. Browse to the DEM file, then select Open button as shown in Figure 14. The Coordinate System form will be displayed, and we must define the correct projection for the cross-section data file. Click the OK button to finish as shown in Figure 15.
After importing the DEM data, to locate in the DEM location, RMC on the XS layer in the Layer Control, then select Zoom to Layer as shown in Figure 16.
Figure 13 Import DEM option.
Figure 14 Import Overlay Layer form.
Figure 15 Define Coordinate System.
Figure 16 Zoom to Layer.
Next, click the Add a New Polyline button from the toolbar, draw the start point of a polyline by LMC and the endpoint by RMC. Note that the polyline must overlay the DEM area. Select the Selection mode by pressing the S key and then LMC on the polyline to select. Next, RMC to display options, and select Show DEM or TIN Profile as shown in Figure 17. The DEM profile is shown as the plot in Figure 18.
Figure 17 Show DEM Profile.
Figure 18 DEM Profile.