How are topo data included in a city?

Altair Forum User

What is the process of including the topography data of a city along with the buildings?

Am I correct in assuming that topography data contains the information about the ground on which the city is located (as the ground is not always flat in real life). Does the topography data also contain the information about where is water, where is vegetation, what type of soil is present at a specific location on the map?

If we don’t include the topography data in an Urban propagation analysis, is the ground always treated to be flat? Is the presence of a flat ground taken into account by adding some losses (internally by ProMan)?

MartinV_20771

The topo data file contains the height above sea level and can be combined with the urban building vector data if the city is not flat.

Typically the building heights are given relative to ground and are then shifted according to the terrain profile (topo data).

This forms the urban scenario for WinProp: building vectors plus topo and optional vegetation also as vector objects. In case of an urban scenario without topo a flat ground without additional losses is assumed. However, you can adapt the propagation exponents if required, or you can consider additional vegetation objects in the urban scenario (with specific loss in dB/m) if needed.

If you wish to include the properties of the ground (water, forest, field, urban, residential, …) then you need also also the clutter file (with the clutter losses and/or heights). This then limits you to a so called rural scenario. An urban scenario doesn't support the clutter map.