Oscillatory shear measurements

Atoll lists the imported DTM, clutter class or traffic objects in their respective folders and creates a separate folder for each imported vector data file and scanned image. Each object is placed on a separate layer. Thus, there are as many layers as imported objects. The layers are arranged from top to bottom in the map window as they appear in the Geo explorer.

It is important to remember that all objects in the Network explorer, such as transmitters, antennas, and predictions, are displayed over all objects in the Geo explorer.

2.11.1 Setting the Display Priority of Geo Data

There are several factors that influence the visibility of geo data:

• The display check box: The check box immediately to the left of the object name in the Geo explorer controls whether or not the object is displayed on the map. If the check box is selected ( ), the object is displayed; if the check box is cleared ( ), the object is not displayed. If the check box, is selected but shaded ( ), not all objects in the folder are displayed. For more information, see "Displaying or Hiding Objects on the Map" on page 31.

• The order of the layers: The layer at the top of the Geo explorer is on top of all other layers in the map window. Data on layers below is only visible where there is no data on the top layer or if you adjust the transparency of the objects on the top layer. You can use drag and drop to change the order of layers by dragging a layer in the Geo explorer towards the top or the bottom of the tab.

• The transparency of objects: You can change the transparency of some objects, such as predictions, and some object types, such as clutter classes, to allow objects on lower layers to be visible on the map. For more information, see "Set-ting the Transparency of Objects and Object Types" on page 34.

• The visibility range of objects: You can define a visibility range for object types. An object is visible only in the map window if the scale, as displayed on the zoom toolbar, is within this range. For more information, see "Setting the Vis-ibility Scale" on page 34.

In Figure 2.6, vector data (including the linear vectors HIGHWAYS, COASTLINE, RIVERLAKE, MAJORROADS, MAJORSTREETS, RAILWAYS and AIRPORT), clutter classes, DTM and scanned image have been imported and a UMTS environment traffic map has been edited inside the computation zone. In the map window, the linear objects (ROADS, RIVERLAKE, etc.) are visible both inside and outside the computation zone. The clutter class layer is visible in the area where there is no traffic data (outside the computation zone). On the other hand, the DTM layer which is beneath the clutter class layer and the scanned map which is beneath the DTM layer, are not visible.

All objects in the Network explorer, such as transmitters, antennas, and predictions, are displayed over all objects in the Geo explorer. Vector geo data, however, can be trans-ferred to the Network explorer, where they can be placed over data such as predictions.

In this way, you can ensure that certain vector geo data, for example, major geographical features, roads, etc., remain visible in the map window For more information, see "Moving a Vector Layer to the Network Explorer" on page 112.

2.11.2 Setting the Priority of Geo Data in Calculations

The priority of geo data in calculations is determined in much the same way as it is for display.

When you make calculations in Atoll, the data taken into account in each folder (Clutter Classes, DTM, etc.) is the data from the top down. In other words, Atoll takes the object on top and objects below only where there is no data in higher levels;

what is used is what is seen.

Object folders, for example, the DTM, clutter classes, clutter heights, and traffic density folders, can contain more than one data object. These objects can represent different areas of the map or the same parts of the map with the same or different resolutions. Therefore for each folder, you should place the objects with the best data at the top. These are normally the objects which cover the least area but have the highest resolution. For example, when calculating coverage in an urban area, you might have two clutter class files: one with a higher resolution for the downtown core, where the density of users is higher, and one with a lower resolution but covering the entire area. In this case, by placing the clutter class file for the down-town core over the file with the lower resolution, Atoll can base its calculations for the downdown-town core on the clutter class file with the higher resolution, using the second file for all other calculations.

The following sections provide examples that illustrate how data is used in Atoll:

• "Example 1: Two DTM Maps Representing Different Areas" on page 117

• "Example 2: Clutter Classes and DTM Maps Representing the Same Area" on page 118

• "Example 3: Two Clutter Class Maps Representing a Common Area" on page 118.

2.11.2.1 Example 1: Two DTM Maps Representing Different Areas

In this example, there are two imported DTM files:

• "DTM 1” represents a given area and has a resolution of 50 m.

• “DTM 2” represents a different area and has a resolution of 20 m.

In this example, the file order of the DTM files in the Explorer window does not matter because they do not overlap; in both Case 1 and Case 2, Atoll will take all the data from both "DTM 1” and "DTM 2” into account.

Figure 2.6: Displaying Geo data layers

The visibility in the context of calculations must not be confused with the display check box ( ). Even if the display check box of an object is cleared ( ), so that the object is not displayed on the map, it will still be taken into consideration for calculations.

Figure 2.7: Multi-layer management in calculations – two DTM maps representing different areas

2.11.2.2 Example 2: Clutter Classes and DTM Maps Representing the Same Area

In this example, there are two imported maps:

• A clutter class map called “Clutter.”

• A DTM map called “DTM”.

Independently of the order of the two maps in the Explorer window, Atoll uses both the clutter and DTM data in calculations.

In Case 1, the clutter class map is on top of the DTM map. In Case 2, the DTM map is on top of the clutter class map. In both Case 1 and Case 2, Atoll will use both the clutter and DTM data in calculations.

Figure 2.8: Multi-layer management in calculations – Clutter and DTM maps representing the same area

2.11.2.3 Example 3: Two Clutter Class Maps Representing a Common Area

In this example, there are two imported clutter classes maps:

• "Clutter 1" represents a large area with a resolution of 50 m.

• "Clutter 2" represents a smaller area with a resolution of 20 m. This area is also covered by "Clutter 1"

In the case of two clutter class maps, Atoll uses the order of the maps in the Clutter Classes folder in the Geo explorer to decide which data to use. In Case 1, "Clutter 2" is on top of "Clutter 1". Atoll will therefore use the data in "Clutter 2" where it is available, and the data from "Clutter 1" everywhere that is covered by "Clutter 1" but not by "Clutter 2." In Case 2,

"Clutter 1" is on top and completely covers "Clutter 2." Therefore, Atoll will only use the data from "Clutter 1."

Explorer window Work space

Case 1 DTM

• DTM 2 (20m)

• DTM 1 (50m)

Case 2 DTM

• DTM 1 (50m)

• DTM 2 (20m)

Explorer window Work space

Case 1 Clutter classes

• Clutter

DTM

• DTM

Case 2 DTM

• DTM

Clutter classes

• Clutter

Figure 2.9: Multi-layer management in calculations – two clutter maps representing the same area