Grid Noise Map SoundPLAN

Grid Noise Map SoundPLAN

SoundPLAN modules Description

(Last Updated On: April 25, 2015)

Grid Noise map in 3D SoundPLAN

Grid Noise map in 3D SoundPLAN

Grid Noise

The Grid Noise Map comes in two variants, as a horizontal map (Grid Noise Maps) where the receivers follow the terrain or in the vertical format as Cross-sectional Noise Map. Spacing of receivers and height above the ground are user selectable. There is no size limit for Grid Noise Maps, however as SoundPLAN can load an unlimited number of Grid Noise Maps into each sheet, it is probably wise to partition the Grid Noise maps for very big areas. Grid Noise Maps have a whole gambit of output options to generate contour lines and smooth them or to leave the grid in place and show the values or have the grid painted in a fluid scale. Cross-sectional Noise Maps are noise maps that start at the terrain and reach to a user selected height, again the receiver spacing us user defined. This mapping option is very user friendly allowing the calculation to be interrupted and resume later on or to calculate a new grid or to re-calculate only part of the grid. If the single PC with multi threaded calculation proves to take too long for the job, with Distributed Computing (DC description is under Tools) the application is scalable to the need of the user.

Transparent triangulation to set the height of receivers

Noise maps show the simulated noise at a given height above the terrain, often at 2 meters. The noise maps are based on a fixed grid of receivers with a customary spacing of either 2, 5 or 10 meters (any spacing is possible in SoundPLAN). To set the elevation of all receivers of a Grid Noise Map, a triangulation of all relevant objects is made (spot elevations, elevation lines, roads, buildings…). The triangulation is the same that is used for the elevation supply in the calculations. These triangulations are part of the “Situation” that is made of relevant objects.

Grid Noise map transparant triangulation SoundPLAN

Grid Noise map transparant triangulation SoundPLAN

In the Geo-Database and in the Graphics, these triangulations can be checked in 2D and in 3D. If the triangulation doesn’t represent the terrain correctly, insert elevation lines or spot elevations to further define the surface. The triangulation follows certain rules, elevation lines, roads, railways and line sources are never intersected by the triangulation to ensure these objects are always on the surface.

Grid versus Calculation Area

Grid Noise Maps have an internal structure of a fixed grid. Multiple Grid Noise Maps share the same origin so it is possible to combine multiple maps to form a singe noise map. Receivers for the maps are only calculated when the receiver falls within the selected calculation area. These calculation areas can be shaped at will.

The lower picture depicts an option in the Graphics where it is possible to highlight the calculation area and dampen the rest of the map.

Grid Noise map free shape calculation area SoundPLAN

Grid Noise map free shape calculation area SoundPLAN

Grid Cross-Sectional Noise Map

Aside from the “normal” terrain following noise map, SoundPLAN offers a mapping option where a vertical noise map is calculated on top of a calculation line. SoundPLAN calls this the Grid Cross-Sectional Noise Map. These noise maps are perfectly suited to document the effectiveness of a noise barrier like in the lower picture. One or multiple Grid Cross-Sectional Noise maps can be combined with other maps and displayed in a 3D solid model.

Grid Noise cross sectional map SoundPLAN

Grid Noise cross sectional map SoundPLAN

The object concept of noise maps

SoundPLAN is capable of calculating and managing a virtually unlimited number of noise maps. In the Graphics you can activate multiple Grid Noise Maps to be displayed at the same time, and it is also possible to view multiple noise maps in 3D along with multiple Grid Cross-Sectional Noise Maps. Just like the Situations and Geo-Files, these objects are the building blocks that can be assembled into the SoundPLAN graphics. Just drag and drop!

Inserting specific contour lines

Often it is important to insert a specific contour line into the graphics. SoundPLAN allows you to insert any number of discrete contour lines and format them the way you want (color, line width, dB value, etc.). As these sub-objects are independent of all other objects, the noise limit contour lines can be used in conjunction with any other formatting option.

Grid Noise map with particular contour lines SoundPLAN

Grid Noise map with particular contour lines SoundPLAN

Grid Noise Maps in 3D

Grid Noise Maps can be displayed in 3D either as the grid map or as a contoured noise map. Fluid scale grid maps are not possible. In order to display the grid map (which was calculated 2 meters above the ground) and not have it cover the road, the grid map was artificially lowered 10 cm below the road surface.

Hot Spots Grid Noise Map

In cities, it can be difficult to point out where noise problems are located. Roads are narrow, and it may be difficult to see on the narrow band along the road where the high noise levels occur. Furthermore, the normal Gris Noise Map does not take affected population numbers into account. The Hot Spot analysis finds how many residents in a radius of 20 or 50 or 100 meters are affected by high noise levels for every grid cell. The radius and the threshold value are user defined. With one glimpse it is possible to see in the entire city where the problem zones are.

This is a great presentation tool!

Grid Noise Map Hot Spots City map SoundPLAN

Grid Noise Map Hot Spots City map SoundPLAN

Noise maps frequency by frequency

For small to medium projects, the Meshed Noise Map not only delivers a high quality alternative to the Grid Noise Map, but also delivers something absolutely unique to SoundPLAN. When a noise map with industrial, frequency dependant sources is calculated using the Meshed Noise Map, it is possible at loading time (in the Graphics when the noise map is selected and loaded into memory) to select which of the frequencies or partial frequency bands the noise map shall display.

As it is possible in SoundPLAN to have multiple noise maps in a single graphics sheet, you can display the same noise map multiple times, one for the low frequencies, one for 500 Hz, one for 1000 Hz and one for all higher frequencies. In the picture to the left, the same noise map was displayed for 31 Hz, 63 Hz, 125 Hz, 250 Hz, 500 Hz, 1 kHz, 2 kHz, 4 kHz and 8 kHz.

The middle picture is an enlargement of a section of the picture above. The picture below shows the selection options for the frequencies and frequency filters.

Grid Noise Map by frequency SoundPLAN

Grid Noise Map by frequency SoundPLAN

Animated Noise Map

SoundPLAN contains a powerful animated noise map for train noise. The calculation that results in this noise map is the basis for finding the maximum noise level, but it can also be presented stand alone.

Click here to see an example of an animated Noise Map by SoundPLAN.