Working with Contours

Contours can be added to the 3D map from the “Contour/Route” page of the 3D options form, or by choosing “Contours” from the Functions menu .

The Contour List Window

The contour list window consists of two lists: a list of transmitters and a list of contours associated with the selected transmitter. To add a contour, start by adding a transmitter using the “Add Transmitter” button. This will open the standard transmitter properties window where the transmitter parameters can be entered (or a transmitter can be loaded from the FCC database). Once the transmitter has be loaded, select it in the “Transmitters” list and press the “Add Contour” button, which will open the contour parameters window. Any number of transmitters with any number of contours is allowed. Clicking the “Transmitter Info” button will generate a text report listing the transmitters properties and display the calculation parameters of all of the transmitter contours.

The Contour Edit Window

The contour editing window is set up as a series of tab sheets which contain the various options for each contour. The "General " tab contains the settings for drawing, the "Calc Area" tab contains the settings for the number of points and arc calculation, and the third tab will change depending on what type of contour is being edited. At the top of this window there is a drop down list box, where you can change the contour type, available types are: FCC Contour, FMPTP Contour, Circle, and Import. An Import contour is used for importing and displaying contours created by other programs. Terrain-3D currently supports importing DTC and PLT files. When "OK" is pressed, the program will perform any necessary calculations for the contour and return the user to the contour list form, where pressing the close button will plot any new/edited curves on the map.

The General Tab

Clicking on the "General" tab will display the general contour display options. Here you can set the color, line width, and choose whether or not to have a label shown with the contour on the map.

The Calc Area Tab

When calculating an entire contour, the number of points (radials) to be calculated can be set to 36, 72, 180, or 360. The calculation of an arc instead of the entire contour is supported (this is useful when using FMPTP because of the large amount of time PTP contours take to calculate). You can specify the start and stop bearing for calculation by using the drop down list boxes. When an arc is calculated, calculations are made for every degree radial.